The Dietary Guidelines for Americans: Development, Implementation, and Considerations for Congress
Congressional research reportMar 28, 2023
Ask Donna
What actually matters in this document.
Text
The Dietary Guidelines for Americans:
Development, Implementation, and
Considerations for Congress
March 28, 2023
Congressional Research Service
https://crsreports.congress.gov
R47488
SUMMARY
The Dietary Guidelines for Americans:
Development, Implementation, and
Considerations for Congress
R47488
March 28, 2023
Matthew B. Barry,
Coordinator
Section Research Manager
The Dietary Guidelines for Americans (DGA) provides federally developed food-based
recommendations designed to promote health and prevent disease. As mandated by the National
Nutrition Monitoring and Related Research Act of 1990 (P.L. 101-445), the guidelines must be
reviewed and updated at least every five years by the Secretaries of the Department of Health and
Human Services (HHS) and Agriculture (USDA). The lead role alternates between the two departments every five years.
To facilitate the development of the DGA, HHS and USDA convene a Dietary Guidelines Advisory Committee (DGAC) on a
periodic basis. The DGAC comprises experts from outside the federal government who are responsible for reviewing the
scientific evidence regarding diet and nutrition and submitting the committee’s conclusions and recommendations in an
advisory report to the HHS and USDA Secretaries. The Secretaries use the DGAC’s report in drafting the DGA.
The DGA is written for a professional audience—for example, policymakers, health care professionals, and federal nutrition
program operators—that is then responsible for translating and implementing the recommendations for the U.S. population.
The USDA has created several educational tools to help translate the DGA into actionable consumer messages. These
educational tools include the Food Guide Pyramid, MyPyramid, and MyPlate. Some research has demonstrated that use of
these tools is associated with more healthful dietary behaviors in U.S. adults. However, the diet quality of the U.S. population
as a whole has not noticeably improved since the DGA was first introduced to consumers in 1980.
By law, the DGA must be based on “the preponderance of the scientific and medical knowledge which is current at the time
the report is prepared.” It is an evidence-based and authoritative policy document that affects nutrition policies and programs
in the United States, including the National School Lunch Program (NSLP); the Supplemental Nutrition Assistance Program
(SNAP); the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC); and the Senior Nutrition
Programs funded by the Older Americans Act (OAA). The guidelines also influence food and nutrition labeling; guide local,
state, and national health promotion and disease-prevention initiatives; and inform various organizations and industries (e.g.,
products developed and marketed by the food and beverage industry).
Due to its impact on federal nutrition policy and consumer choices, the DGA is of interest to public health, nutrition,
agriculture, and food industry stakeholders, who are given opportunities to provide input throughout the DGA development
process. In some years, stakeholders and policymakers have expressed concerns with various aspects of the DGA
development process, such as the scope of the DGAC’s recommendations, the process by which the DGAC made its
conclusions and recommendations, and specific recommendations. In response to these concerns, Congress has included
DGA-related policy riders in appropriations laws. For example, provisions in the FY2016 Consolidated Appropriations Act
(P.L. 114-113) limited the scope of the DGA and directed the National Academies of Science, Engineering, and Medicine
(NASEM) to review the DGA and its development process. Subsequent appropriations provisions required NASEM to study
HHS and USDA’s implementation of its recommendations. Pursuant to these directives, NASEM published a series of
reports providing recommendations for modifying the DGA development process and evaluating HHS and USDA’s adoption
of its recommendations.
The development process for the 2025-2030 DGA, the 10th edition of the policy document, is underway, with the 2025
DGAC having held its first public meeting on February 9, 2023. Like the 2020 DGAC, the 2025 committee will take a
lifespan approach, examining the relationship between diet and health across all life stages, from birth through older
adulthood. The 2025 DGAC will approach its evidence review with a “health equity lens.” The 2025 DGAC is scheduled to
meet six times throughout 2023 and 2024 and to submit its advisory report to HHS and USDA by October 2024.
This report describes the history of the DGA, the process by which HHS and USDA update the DGA, and implementation of
the DGA in selected federal programs. This report also provides an overview of issues that have arisen with the DGA in
recent years, discusses the DGA’s impact on the health of the U.S. population, and concludes with a discussion of the role of
and considerations for Congress.
Congressional Research Service
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Contents
Introduction ..................................................................................................................................... 1
History of the DGA ......................................................................................................................... 3
Changes in Methods for Reviewing the Evidence .................................................................... 6
Changes in the Populations Addressed by the Guidelines ........................................................ 8
Changes in Scientific Evidence ................................................................................................. 9
Dietary Patterns................................................................................................................... 9
Cholesterol ........................................................................................................................ 10
Added Sugars ..................................................................................................................... 11
The DGA Development Process .................................................................................................... 12
Establishment of a DGAC ....................................................................................................... 13
NASEM Recommendations .............................................................................................. 14
Identification of Scientific Questions ...................................................................................... 15
NASEM Recommendations .............................................................................................. 17
DGAC Review of the Evidence .............................................................................................. 17
NASEM Recommendations .............................................................................................. 18
HHS and USDA Develop the DGA ........................................................................................ 20
NASEM Recommendations .............................................................................................. 21
Examples of Implementation of the DGA ..................................................................................... 21
FDA and Nutrition Labeling ................................................................................................... 21
USDA and School Meal Programs .......................................................................................... 22
Controversies in the DGA ............................................................................................................. 23
The 2015-2020 DGA............................................................................................................... 23
The 2020-2025 DGA............................................................................................................... 25
The DGA and the Health of the U.S. Population........................................................................... 26
Communication of Dietary Recommendations ....................................................................... 27
Access to Healthy Food and the Food Environment ............................................................... 29
Trust in Nutrition Science ....................................................................................................... 30
Congress and the DGA .................................................................................................................. 31
Figures
Figure 1. The DGA Development Process .................................................................................... 13
Figure 2. Healthy Eating Index (HEI)-2015 Scores 2005-2018 .................................................... 27
Figure 3. Nutrition Education Tools .............................................................................................. 28
Tables
Table 1. The DGA: 1980 to Present ................................................................................................ 5
Appendixes
Appendix A. Summary of NASEM Reports ................................................................................. 33
Congressional Research Service
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Appendix B. The DGAC’s Approaches to Reviewing the Evidence ............................................ 35
Contacts
Author Information........................................................................................................................ 37
Congressional Research Service
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Introduction
The Dietary Guidelines for Americans (DGA) is a policy document that provides federally
developed food-based recommendations to promote health and prevent disease in the United
States. As mandated by the National Nutrition Monitoring and Related Research Act of 1990 (P.L.
101-445), the DGA must be reviewed and updated at least every five years by the Secretaries of
the Department of Health and Human Services (HHS) and Agriculture (USDA).
The DGA is issued jointly by HHS and USDA, with the lead role alternating between the two
departments every five years. USDA was the administrative lead for the 2020-2025 DGA, and
HHS is the administrative lead for the 2025-2030 DGA. Among other responsibilities, the
administrative lead for the DGA is responsible for chartering the Dietary Guidelines Advisory
Committee (DGAC)—a group of experts from outside the federal government charged with
reviewing the scientific evidence regarding diet and nutrition and submitting its conclusions and
recommendations in an advisory report to the HHS and USDA Secretaries.1 The Secretaries
consider the DGAC’s report when drafting the final DGA policy document.
By law, the DGA must “contain nutritional and dietary information and guidelines for the general
public” and “be based on the preponderance of the scientific and medical knowledge which is
current at the time the report is prepared.”2 In accord with this statutory mandate, the DGA
provides dietary advice in order to promote health and prevent disease.3 While various editions of
the DGA have addressed physical activity, a separate policy document issued by HHS—the
Physical Activity Guidelines for Americans—provides more extensive guidance on the
importance of exercise and is intended to complement the DGA.4
The DGA is written for a professional audience—for example, policymakers, health care
professionals, and federal nutrition program operators—that is then responsible for translating
and implementing the guidelines for the U.S. population. It is an evidence-based and authoritative
policy document that affects nutrition policies and programs in the United States, including the
National School Lunch Program (NSLP); the Supplemental Nutrition Assistance Program
(SNAP); the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC);
and the Senior Nutrition Programs funded by the Older Americans Act (OAA). The guidelines
also influence food and nutrition labeling; guide local, state, and national health promotion and
disease-prevention initiatives; and inform various organizations and industries (e.g., products
developed and marketed by the food and beverage industry).
Due to its impact on federal nutrition policy and consumer choices, the DGA is of interest to
public health, nutrition, agriculture, and food industry stakeholders, who are given opportunities
to provide input throughout the DGA development process. In some years, stakeholders and
policymakers have expressed concerns with various aspects of the DGA development process,
such as the DGAC’s composition, the scope of its recommendations, and the process by which
the DGAC made its conclusions and recommendations. In response to these concerns, Congress
1 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, July 2020, Part C. Methodology, p. 4,
https://www.dietaryguidelines.gov/sites/default/files/2020-07/
ScientificReport_of_the_2020DietaryGuidelinesAdvisoryCommittee_first-print.pdf.
2 P.L. 101-445, §301(a).
3 Ibid. DGA, “Purpose of the Dietary Guidelines,” https://www.dietaryguidelines.gov/about-dietary-guidelines/
purpose-dietary-guidelines.
4 For additional information, see HHS, Physical Activity Guidelines for Americans, 2nd Edition, 2018,
https://health.gov/sites/default/files/2019-09/Physical_Activity_Guidelines_2nd_edition.pdf.
Congressional Research Service
1
The Dietary Guidelines for Americans: Overview and Considerations for Congress
included several DGA-related policy riders in the FY2016 Consolidated Appropriations Act (P.L.
114-113) and subsequent appropriations laws.5 These laws limited the scope of the DGA and
directed the National Academies of Science, Engineering, and Medicine (NASEM) to review the
DGA and its development process.
NASEM appointed an ad hoc committee to conduct the evaluation and, in 2017, published two
reports on the DGA development process and recommendations for change.6 Pursuant to a
directive in the FY2021 Consolidated Appropriations Act (P.L. 116-260), NASEM convened a
new ad hoc committee and, in 2022, published two reports evaluating HHS and USDA’s adoption
of its recommendations in the development of the 2020-2025 DGA.7 NASEM’s recommendations
and evaluation of the department’s implementation of the recommendations are summarized in a
text box in Appendix A. Select recommendations are also discussed throughout this report, where
relevant.
The development process for the 2025-2030 DGA, the 10th edition of the policy document, is
underway, with the 2025 DGAC having held its first public meeting on February 9, 2023. Like
the 2020 DGAC, the 2025 committee will take a lifespan approach, examining the relationship
between diet and health across all life stages, from birth through older adulthood. This approach
will include examining the relationship between diet and risk of overweight and obesity, with a
new emphasis on weight loss and weight maintenance.8 In addition, the 2025 DGAC will
approach its evidence review with a “health equity lens ... to ensure factors such as
socioeconomic status, race, ethnicity, and culture are described and considered to the greatest
extent possible based on the information provided in the scientific literature and data.”9 The 2025
DGAC is scheduled to meet six times throughout 2023 and 2024 and to submit its advisory report
to HHS and USDA by October 2024.10
This report begins with a history of the DGA, including how the guidelines have changed over
time. It then describes the process by which HHS and USDA update the DGA, including the work
of the DGAC and changes made to the DGA development process over time, and examples of
implementation of the DGA in federal programs. It then provides an overview of controversies
that have arisen with the DGA in recent years, discusses the DGA’s impact on the health of the
U.S. population, and concludes with a discussion of the role of and considerations for Congress.
Historically, the title of the DGA has reflected the year in which the document was published (or
was intended to be published). For example, the sixth edition of the DGA, published in December
2005, was titled Dietary Guidelines for Americans 2005. Beginning with the 2015-2020 DGA,
HHS and USDA have titled the policy document using the five-year period it is intended to cover
(e.g., Dietary Guidelines for Americans 2015-2020, Dietary Guidelines for Americans 20202025). Consistent with the departments’ naming convention, this report refers to DGA editions
published prior to 2015 using the publication year (e.g., 2005 DGA); editions published in 2015
and later are referred to using the five-year period that they cover (e.g., 2015-2020 DGA). This
5 P.L. 114-113, §735; P.L. 116-6, §766; P.L. 116-260, §796.
6 National Academies of Sciences, Engineering, and Medicine (NASEM), Optimizing the Process for Establishing the
Dietary Guidelines for Americans: The Selection Process, 2017, and Redesigning the Process for Establishing the
Dietary Guidelines for Americans, 2017 (Washington, DC: National Academies Press).
7 NASEM, Evaluating the Process to Develop the Dietary Guidelines for Americans, 2020-2025: A Midcourse Report,
2022, and Evaluating the Process to Develop the Dietary Guidelines for Americans, 2020-2025: Final Report, 2022
(Washington, DC: National Academies Press).
8 DGA, 2025 Dietary Guidelines Advisory Committee, “Proposed Scientific Questions,”
https://www.dietaryguidelines.gov/sites/default/files/2022-07/Proposed%20Scientific%20Questions_508c_Final.pdf.
9 DGA, “About the Committee,” https://www.dietaryguidelines.gov/2025-advisory-committee.
10 2025 Dietary Guidelines Advisory Committee: Meeting 1, February 9 and 10, 2023.
Congressional Research Service
2
The Dietary Guidelines for Americans: Overview and Considerations for Congress
report refers to each DGAC using a single year (e.g., the 2015 DGAC refers to the committee that
assisted with development of the 2015-2020 DGA), also consistent with HHS and USDA
documents.
Key Terms Used Throughout This Report
Dietary Guidelines for Americans (DGA): the policy document issued by HHS and USDA every five years
that serves as the basis for nutrition policies and programs in the United States.
Dietary Guidelines Advisory Committee (DGAC): the committee of experts from outside the federal
sector that is responsible for reviewing the current science and submitting its recommendations, as well as the
scientific rationale for those recommendations, in an advisory report to the Secretaries of HHS and USDA.
DGAC’s Report: the scientific advisory report of the DGAC, which is used by the Secretaries of HHS and
USDA to inform the DGA policy document.
National Academies of Sciences, Engineering, and Medicine (NASEM): independent institution that
provides expert advice on various topics, including the DGA development process.
Nutrition Evidence Systematic Review (NESR): the staff at USDA who specialize in conducting systematic
reviews to answer nutrition- and health-related questions to inform federal nutrition policies and programs.
History of the DGA
The federal government has been issuing dietary guidance for the public as far as back as 1894,
when the USDA published its first dietary recommendations.11 Early nutrition guidance generally
focused on nutrition adequacy (i.e., consuming enough nutrients). By the 1970s, however, a
growing body of research had identified a link between overconsumption of certain nutrients
(e.g., saturated fat and sodium) and the development of chronic diseases such as cardiovascular
disease (CVD) and stroke.12
To help improve the diet of the U.S. population and reduce the risk of diet-related chronic
disease, in February 1977, the U.S. Senate Select Committee on Nutrition and Human Needs
published Dietary Goals for the United States, a predecessor to the DGA. Among other things,
Dietary Goals for the United States made several quantitative recommendations around dietary
intake; for example, to increase carbohydrate intake to account for 55%-60% of total daily
calories and to reduce fat intake from 40% to 30% of total daily calories.13 This document was
criticized by some industry groups and scientific experts who questioned whether the available
evidence supported these quantitative goals.14 After a series of hearings and input from industry,
scientists, and the public, in December 1977, the committee issued an updated document, Dietary
Goals for the United States, Second Edition.15 Although many of the same goals and quantitative
recommendations carried over to the second edition, there were several modifications. For
11 C. Davis and E. Altos, “Dietary Recommendations and How They Have Changed Over Time,” in America’s Eating
Habits: Changes and Consequences, Agriculture Information Bulletin No. 750 (1999, Washington DC; Economic
Research Service, USDA), pp. 33-50.
12 Ibid.
13 U.S. Congress, Senate Select Committee on Nutrition and Human Needs, Dietary Goals for the United States,
committee print, 95th Cong., 1st sess., February 1977.
14 2015 Dietary Guidelines Advisory Committee DGAC MEETING 1: Materials and Presentations, June 13-14, 2013,
https://web.archive.org/web/20151117075627/http://health.gov/dietaryguidelines/2015-BINDER/meeting1/
historyCurrentUse.aspx. See also L. Jahns, W. Davis-Shaw, A. Lichtenstein, “The History and Future of Dietary
Guidance in America,” Advances in Nutrition, March 2018, vol. 9, no. 2, pp. 136-147.
15 U.S. Congress, Senate Select Committee on Nutrition and Human Needs, Dietary Goals for the United States,
Second Edition, committee print, 95th Cong., 1st sess., December 1977.
Congressional Research Service
3
The Dietary Guidelines for Americans: Overview and Considerations for Congress
example, the second edition included a new goal to consume only as many calories as are
expended to avoid weight gain and to decrease calorie intake and increase calorie expenditure if
overweight. The goal to increase carbohydrate consumption from 55% to 60% was changed to
increase consumption of complex carbohydrates and “naturally occurring” sugars from 28% to
48% of daily caloric intake.16
In response to continued criticisms of the Senate committee’s reports, HHS (then called the
Department of Health, Education, and Welfare) and USDA selected scientists from the
departments to review the evidence, with input from the scientific community, in order to provide
authoritative and consistent guidance on diet and health.17 This work resulted in the publication of
the first edition of the DGA—a brochure titled Nutrition and Your Health: Dietary Guidelines for
Americans—which provided seven principles for a healthful diet.18
Some industry and scientific groups continued to express concerns regarding the science used to
develop the recommendations, and in 1980, a Senate Committee on Appropriations report
directed that an external committee be established to review scientific evidence and recommend
revisions to the DGA.19 In 1983, an advisory committee of nine nutrition scientists from outside
the federal government was convened to review the 1980 DGA and make recommendations for
revisions, which were submitted in a report to the Secretaries of USDA and HHS. In 1985, USDA
and HHS published Nutrition and Your Health: Dietary Guidelines for Americans, 2nd edition,
which contained almost the same recommendations as the first edition but was more widely
accepted.20 Subsequently, in 1987, a House Committee on Appropriations conference report
directed HHS and USDA to “reestablish a Dietary Guidelines Advisory Group on a periodic
basis. This Advisory Group will review the scientific data relevant to nutritional guidance and
make recommendations on appropriate changes to the Secretaries of the Departments of
Agriculture and Health and Human Services.”21 A DGAC has been used to develop the DGA
since then.
In 1990, Congress passed the National Nutrition Monitoring and Related Research Act (P.L. 101445), which required the Secretaries of HHS and USDA to publish, at least every five years, a
report titled Dietary Guidelines for Americans, which “shall contain nutritional and dietary
information and guidelines for the general public, and shall be promoted by each Federal agency
in carrying out any Federal food, nutrition, or health program.”22 The 1995 DGA was the first
statutorily mandated edition of the DGA. (The 1980, 1985, and 1990 editions were issued
voluntarily by HHS and USDA.)
Over the years, the DGA has evolved from an educational brochure for consumers to a policy
document for policy officials, health care providers, nutrition educators, and federal nutrition
16 Ibid.
17 2015 Dietary Guidelines Advisory Committee DGAC MEETING 1: Materials and Presentations, June 13-14, 2013.
18 USDA and HHS, Nutrition and Your Health: Dietary Guidelines for Americans, February 1980,
https://www.dietaryguidelines.gov/about-dietary-guidelines/previous-editions/1980-dietary-guidelines-americans.
19 2015 Dietary Guidelines Advisory Committee DGAC MEETING 1: Materials and Presentations, June 13-14, 2013.
U.S Senate Agricultural Appropriations Committee (US Senate). 96th Cong., 1st sess., 1980, S.Rept. 96-1030.
20 USDA and HHS, Nutrition and Your Health: Dietary Guidelines for Americans, 2nd edition, August 1985,
https://www.dietaryguidelines.gov/about-dietary-guidelines/previous-editions/1985-dietary-guidelines-americans. See
also, 2015 Dietary Guidelines Advisory Committee DGAC MEETING 1: Materials and Presentations, June 13-14,
2013.
21 U.S. House of Representatives Conference Committee, 100th Cong., 1st sess., 1987, H.Rept. 100-498.
22 P.L. 101-445, §301(a).
Congressional Research Service
4
The Dietary Guidelines for Americans: Overview and Considerations for Congress
program operators.23 The first four editions of the DGA contained seven guidelines (see Table 1).
By 2005, that number had increased to 41 (23 for the general public and 18 for specific
populations). The 2015-2020 DGA included five overarching guidelines, and the 2020-2025 DGA
included four overarching guidelines, supported by “key recommendations” such as quantitative
limits on certain nutrients. Despite fluctuations in the number of guidelines, the basic tenets of the
seven original guidelines have been carried through across editions.
Table 1. The DGA: 1980 to Present
Title and
Edition
Date
Issued
Nutrition and Your
Health: Dietary
Guidelines for
Americans
February
1980
Method for
Reviewing the
Evidence
Target
Audience
Focus of
Guidance
Number of
Guidelines
Review of current
Consumers
science by select
scientists from HHS and
USDA, along with
expertise of the
scientific community
Healthy
Americans (age
not specified)
7
Nutrition and Your
Health: Dietary
Guidelines for
Americans, 2nd
edition
August 1985 Establishment of DGAC Consumers
and use of DGAC’s
collective knowledge of
nutrition; search and
review of the scientific
literature
Healthy
Americans (age
not specified)
7
Nutrition and Your
Health: Dietary
Guidelines for
Americans, 3rd
edition
November
1990
DGAC’s collective
Consumers
knowledge of nutrition;
search and review of
the scientific literature
Healthy
Americans, two
years of age and
older
7
Nutrition and Your
Health: Dietary
Guidelines for
Americans, 4th
edition
December
1995
DGAC’s collective
Consumers
knowledge of nutrition;
search and review of
the scientific literature
Healthy
Americans, two
years of age and
older, to
promote health
and prevent
disease
7
Nutrition and Your
Health: Dietary
Guidelines for
Americans, 5th
edition
May 2000
DGAC’s collective
knowledge of nutrition;
search and review of
the scientific literature
Consumers,
Healthy
policy officials, Americans two
nutritionists, years of age and
nutrition
older, to
educators
promote health
and decrease risk
of certain chronic
diseases
10 (clustered into
three groups)
Dietary Guidelines
for Americans
2005, 6th edition
January 2005 Modified evidencebased approach, data,
analyses, food pattern
modeling analyses
Policy officials, Americans two
nutritionists, years of age and
nutrition
older, to
educators
promote health
and decrease risk
of major chronic
diseases
41 (23 for general
population, 18 for
specific population
groups)
23 DGAC Meeting 1, “The Dietary Guidelines for Americans: 1980 to Present,” https://web.archive.org/web/
20150920083150/http://health.gov/dietaryguidelines/2015-binder/meeting1/evolutionOfDietaryGuidelines.aspx.
Congressional Research Service
5
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Title and
Edition
Date
Issued
Method for
Reviewing the
Evidence
Target
Audience
Focus of
Guidance
Number of
Guidelines
Dietary Guidelines
for Americans
2010, 7th edition
January 2011 NESR, data analyses,
food pattern modeling
analyses, and other
scientific reports
Policy officials, Americans two
nutritionists, years of age and
nutrition
older, including
educators
those at risk of
chronic diseases,
to promote
health and
decrease risk of
major chronic
diseases
29 (23 for general
population, 6 for
specific population
groups)
Dietary Guidelines
for Americans
2015-2020, 8th
edition
January 2016 NESR, data analyses,
food pattern modeling
analyses, and other
scientific reports
Policy officials, Americans two
nutritionists, years of age and
nutrition
older, including
educators
those at risk of
chronic diseases,
to promote
health and
decrease risk of
major chronic
diseases
5 overarching
guidelines
(accompanied by
recommendations)
Dietary Guidelines
for Americans,
2020-2025, 9th
edition
December
2020
NESR, data analyses,
and food pattern
modeling analyses
Policy officials, Americans from
nutritionists, birth until older
nutrition
adulthood to
educators
promote health
and decrease risk
of major chronic
diseases
4 overarching
guidelines
(accompanied by
recommendations)
Dietary Guidelines
for Americans,
2025-2030, 10th
edition
Expected
December
2025
NESR, data analyses,
and food pattern
modeling analyses
Policy officials, Americans from
nutritionists, birth until older
nutrition
adulthood to
educators
promote health
and decrease risk
of major chronic
diseases
To be determined
Source: Created by CRS based on the 1980 through 2020-2025 DGA and accompanying DGAC reports, as
well as materials from DGAC Meeting 1, “The Dietary Guidelines for Americans: 1980 to Present”; see
https://web.archive.org/web/20150920083150/http://health.gov/dietaryguidelines/2015-binder/meeting1/
evolutionOfDietaryGuidelines.aspx.
Notes: DGA = Dietary Guidelines for Americans DGAC = Dietary Guidelines Advisory Committee; NESR =
Nutrition Evidence Systematic Review.
Although the nine editions of the DGA have generally contained similar recommendations
regarding what constitutes a healthy diet, the guidelines have evolved to reflect the latest
scientific evidence and to address a broader population. In addition, the approach for DGAC’s
review of the scientific evidence has changed over time. These changes are described in more
detail below.
Changes in Methods for Reviewing the Evidence
Although each edition of the DGA has been based on the scientific evidence available at the time
it was developed, the methods for reviewing the science have evolved, and the DGA has become
Congressional Research Service
6
The Dietary Guidelines for Americans: Overview and Considerations for Congress
more evidence-based over time.24 The DGA editions released from 1980 through 2000 were
generally based on the collective knowledge of the DGAC and literature reviews conducted by
committee members (see Table 1). For the 2005 DGA, the DGAC took a new approach to its
scientific review in which the committee identified specific research questions related to dietary
guidance, which were then subject to an “evidence-based analysis of the science.”25 The 2005
DGAC relied upon existing reports, such as the Dietary Reference Intake reports prepared by
expert committees convened by the Institute of Medicine (now the National Academy of
Medicine) and various Agency for Healthcare Research and Quality (AHRQ) and World Health
Organization (WHO) reports, as well as data analysis and food pattern modeling analyses
completed by USDA.26
In 2008, the USDA Center for Nutrition Policy and Promotion (CNPP) developed the Nutrition
Evidence Library (NEL), now called the Nutrition Evidence Systematic Review (NESR), to
conduct food- and nutrition-related systematic reviews. The NESR has been used by each DGAC
since 2010. In 2019, CNPP changed the name from NEL to NESR to convey that NESR is “a
team of professionals who specialize in conducting systematic reviews on food- and nutritionrelated topics, rather than a library that collects, houses, or conducts original nutrition research.”27
For consistency, this report uses the term NESR throughout.
Today, the DGACs primarily use three approaches to review the scientific evidence: NESR
systematic reviews, data analyses, and food pattern modeling. These approaches are described in
more detail in Appendix B. Some DGACs have also continued to rely upon existing reports and
systematic reviews. For example, the 2010 and 2015 DGAC used existing systematic reviews and
reports to avoid duplicating efforts, and the 2025 DGAC may use non-NESR systematic reviews,
provided they are as rigorous and transparent as NESR systematic reviews.28
Over time, the NESR systematic review process has been modified for the purposes of DGA
development. For example, for the 2020-2025 DGA, HHS and USDA added a peer review step to
the NESR systematic review process, in response to recommendations from NASEM, as well as
stakeholder comments and the understanding that peer review is a best practice for conducting
systematic reviews.29 Specifically, each NESR systematic review was peer reviewed by two
federal scientists, with 47 scientists from various federal agencies participating in the peer review
process.30 In addition, the protocol for each systematic review question was made available for
public comment before the DGAC began its review of the evidence.31 New to the 2025-2030
DGA development process, NESR intends to conduct a limited number of meta-analyses, which
use quantitative analysis to combine data from individual studies.32
24 NASEM, Redesigning the Process for Establishing the Dietary Guidelines for Americans, 2017 (Washington, DC:
National Academies Press), p. 4.
25 Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2005, August 2004,
Letter to Secretaries Thompson and Veneman, August 19, 2004, p. 4, https://www.dietaryguidelines.gov/sites/default/
files/2019-10/FINAL2005DGACReport.pdf.
26 Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2005, Part C.
Methodology, pp. 21-25.
27 USDA, “About NESR (formerly NEL),” https://nesr.usda.gov/about.
28 2025 Dietary Guidelines Advisory Committee, Meeting 1, February 9, 2023.
29 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part C. Methodology, p. 45.
30 Ibid.
31 Ibid., pp. 18-19.
32 2025 Dietary Guidelines Advisory Committee, Meeting 1, February 9 and 10, 2023.
Congressional Research Service
7
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Changes in the Populations Addressed by the Guidelines
Until 2020, the DGA had provided recommendations for individuals two years of age and older,
with the exception of the 1980 and 1985 DGA, which mentioned infants’ nutritional needs and
the importance of human breast milk.33 The Agricultural Act of 2014 (P.L. 113-79, the “2014 farm
bill”) required that beginning in 2020, the DGA include recommendations for the birth-to-24months cohort, as well as pregnant women.34 As a result, the 2020-2025 DGA covers the full
lifespan and includes specific recommendations and chapters that address infants and toddlers, as
well as pregnant and lactating women. Understanding that early food preferences influence food
choices later in life, the 2020-2025 DGA, for the first time, provides recommendations by
lifespan—from birth through older adulthood—identifying dietary and nutrition needs that are
specific to each life stage and considering healthy dietary pattern characteristics that should be
carried through to subsequent life stages.35 This lifespan approach will also be used by the 2025
DGAC for the development of the 2025-2030 DGA.36
The DGA has changed over time to address a U.S. population with high rates of obesity and dietrelated chronic diseases, such as type 2 diabetes and cardiovascular disease (CVD). More than
74% of U.S. adults are overweight or have obesity, and 40% of children and adolescents are
overweight or have obesity.37 An estimated 60% of U.S. adults have at least one diet-related
chronic disease.38
Although the early editions of the DGA were generally intended for healthy Americans, by 2010
the DGA began to explicitly address Americans at risk of diet-related chronic disease.39 The 2010
DGAC report noted that it was different from previous reports in several ways, including that it
addressed “an American public of whom the majority are overweight or obese and yet undernourished in several key nutrients.”40 Similarly, the 2015 DGAC indicated that its work was
33 USDA and HHS, Nutrition and Your Health: Dietary Guidelines for Americans, February 1980, p. 6, and Nutrition
and Your Health: Dietary Guidelines for Americans, 2nd edition, August 1985, pp. 7-8.
34 P.L. 113-79, §4204.
35 USDA and HHS, Dietary Guidelines for Americans, 2020-2025, 9th edition, December 2020, Executive Summary p.
viii, https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdf.
36 DGA, “About the Committee,” https://www.dietaryguidelines.gov/2025-advisory-committee.
37 According to National Health and Nutrition Examination Survey (NHANES) data for 2017 to March 2020, the U.S.
prevalence of adult obesity—defined as obesity in individuals 20 years of age and older—was 41.9%, with prevalence
rates highest among non-Hispanic Black adults (49.9%), followed by Hispanic (45.6%) and non-Hispanic white
(41.4%) adults; obesity prevalence in non-Hispanic Asian adults was 16.1%.37 The prevalence of severe obesity in
adults was 9.2%. NHANES data for 2017 to March 2020 indicate that the prevalence of childhood obesity—defined as
obesity in children and adolescents 2-19 years of age—was 19.7%, with rates highest among Hispanic (26.2%) and
non-Hispanic Black (24.8%) children and adolescents, followed by non-Hispanic white (16.6%) and non-Hispanic
Asian (9.0%) children and adolescents. B. Stierman, J. Afful, and M. Carroll, “National Health and Nutrition
Examination Survey 2017-March 2020 Prepandemic Data Files—Development of Files and Prevalence Estimates for
Selected Health Outcomes,” National Health Statistics Reports, June 14, 2021, no. 158, https://stacks.cdc.gov/view/
cdc/106273. Because the COVID-19 pandemic halted field operations, data collected in the partial 2019-2020 cycle
were not nationally representative and thus were combined with previously released data for 2017-2018 to produce
nationally representative estimates.
38 USDA and HHS, Dietary Guidelines for Americans, 2020-2025, p. 5.
39 USDA and HHS, Dietary Guidelines for Americans 2010, 7th edition, December 2010, Chapter 1: Introduction, p. 1,
https://www.dietaryguidelines.gov/sites/default/files/2019-05/DietaryGuidelines2010.pdf.
40 Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010, May 2010,
Part A: Executive Summary, p. 1, https://www.dietaryguidelines.gov/sites/default/files/2019-10/
FINAL2005DGACReport.pdf.
Congressional Research Service
8
The Dietary Guidelines for Americans: Overview and Considerations for Congress
guided, in part, by the high prevalence of preventable chronic disease among U.S. adults.41 The
2020 DGAC’s report mentioned that like the 2010 and 2015 DGACs, the committee’s work “took
place against a backdrop of several significant nutrition-related issues in the United States,”
noting high rates of obesity and diet-related chronic diseases, as well as food insecurity and lack
of access to affordable healthy food.42
Changes in Scientific Evidence
Each edition of the DGA reflects the state of the scientific evidence available at the time the
DGAC conducts its work. As such, certain recommendations have been modified over time to
reflect newer science. For example, beginning with the 2010 DGAC, the committees noted the
importance of focusing on dietary patterns rather than specific foods, reflecting the more recent
understanding that people do not eat foods in isolation but rather in various combinations over
time. In addition, recommendations for specific nutrients and food components such as
cholesterol and sugar have been modified to reflect new scientific evidence. These changes are
described in more detail below.
Dietary Patterns
Over time, the DGA has evolved from focusing on individual nutrients to dietary patterns, defined
as “the quantities, proportions, variety, or combination of different foods, drinks, and nutrients in
diets, and the frequency with which they are habitually consumed.”43 The DGA shifted its focus
from individual foods and nutrients to dietary patterns because foods and nutrients are not eaten
in isolation. Instead, they are consumed as part of a pattern over the lifespan. Evidence suggests
that foods and nutrients have synergistic effects, and that dietary patterns—rather than single
foods or nutrients—may have a stronger association with specific health outcomes.44 The 2010
DGAC’s report discussed the importance of dietary patterns and recommended more research
into this area. Subsequently, the 2015 DGAC was the first DGAC to explore the impact of dietary
patterns on specific health outcomes, and by 2020, the DGAC “made dietary patterns a
centerpiece of its report.”45
Healthy dietary patterns can be achieved in multiple ways with different foods and beverages.
The USDA has developed three dietary patterns to allow for flexibility in how DGA
recommendations can be met. These are the Healthy U.S.-Style Pattern, the Healthy Vegetarian
Pattern, and the Healthy Mediterranean-Style Pattern. Each of these patterns identifies daily
amounts of foods to eat from five major food groups (i.e., fruits, vegetables, grains, protein, and
dairy) and their subgroups (e.g., dark green vegetables), with an allowance for oils and a limit on
the maximum number of discretionary calories, for example, from added sugars.46
Consistent with the dietary patterns approach, the 2015 DGAC assessed the impact of dietary
patterns on seven broad health outcomes: CVD, body weight, type 2 diabetes, cancer, congenital
41 Scientific Report of the 2015 Dietary Guidelines Advisory Committee, February 2015, Part A: Executive Summary, p.
1, https://health.gov/sites/default/files/2019-09/Scientific-Report-of-the-2015-Dietary-Guidelines-AdvisoryCommittee.pdf.
42 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part A: Executive Summary, pp.1-2.
43 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part D. Chapter 8: Dietary Patterns, p.1.
44 Scientific Report of the 2015 Dietary Guidelines Advisory Committee, Part A. Executive Summary, p. 3.
45 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part A. Executive Summary, p. 2.
46 USDA, “USDA Food Patterns,” https://www.fns.usda.gov/usda-food-patterns.
Congressional Research Service
9
The Dietary Guidelines for Americans: Overview and Considerations for Congress
anomalies, neurological and psychological illnesses, and bone health.47 For example, the
committee examined the relationship between dietary patterns and CVD, concluding that
strong and consistent evidence demonstrates that dietary patterns associated with decreased
risk of CVD are characterized by higher consumption of vegetables, fruits, whole grains,
low-fat dairy, and seafood, and lower consumption of red and processed meat, and lower
intakes of refined grains, and sugar-sweetened foods and beverages relative to less healthy
patterns. Regular consumption of nuts and legumes and moderate consumption of alcohol
also are shown to be components of a beneficial dietary pattern in most studies.48
Subsequently, the 2020 DGAC assessed the relationship between dietary patterns and eight broad
health outcomes, including some of those examined by the 2015 DGAC (e.g., CVD, type 2
diabetes),49 as well as the relationship between dietary patterns and health outcomes during
pregnancy and lactation.
Cholesterol
One nutrient-specific DGA guideline that has been modified over time concerns dietary
cholesterol and, specifically, a quantitative limit for dietary cholesterol. As early as 1977, the
Dietary Goals for the United States Second Edition noted a lack of consensus among nutrition
scientists and research professionals as to whether a specific restriction of dietary cholesterol
intake for the general population was warranted.50 While each edition of the DGA has
recommended keeping dietary cholesterol low, only the 2005 and 2010 DGA included a specific
quantitative limit.
The 2005 DGA was the first edition to include a quantitative intake guideline for dietary
cholesterol. This recommendation was informed by the 2005 DGAC, which concluded that the
relationship between dietary cholesterol and blood low-density lipoprotein (LDL) cholesterol is
“direct and progressive, increasing the risk of [coronary heart disease] CHD,” and recommended
that cholesterol intake should be as low as possible.51 The DGAC recommended a daily dietary
intake of less than 300 mg for the general population and less than 200 mg per day for those with
elevated LDL.52 The DGAC based its conclusion on a systematic review of the evidence, noting
there was a historical basis for this recommendation.53 Similarly, the 2010 DGA recommended
limiting dietary cholesterol intake to less than 300 mg per day. In its advisory report, the 2010
DGAC concluded that there is moderate evidence that links dietary cholesterol intake to clinical
CVD endpoints.54 This conclusion was based on an NESR systematic review, as well as a food
47 Scientific Report of the 2015 Dietary Guidelines Advisory Committee, Part D. Chapter 2: Dietary Patterns, Foods and
Nutrients, and Health Outcomes, pp. 185-186.
48 Ibid., p. 188.
49 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part D. Chapter 8: Dietary Patterns, p. 14. The
2020 DGAC assessed the following eight outcomes: CVD, overweight and obesity, type 2 diabetes, neurocognitive
health, bone health, risk of certain types of cancer, sarcopenia, and all-cause mortality.
50 U.S. Congress, Senate Select Committee on Nutrition and Human Needs, Dietary Goals for the United States,
Second Edition, committee print, 95th Cong., 1st sess., December 1977.
51 Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010, May 2010, p.
129. The DGAC specifically examined the scientific research question, “What Are the Relationships Between
Cholesterol Intake and Cardiovascular Disease?” LDL cholesterol is sometimes called “bad” cholesterol because it can
build up in blood vessel walls, restricting blood flow to the heart and other organs.
52 Ibid.
53 The 2005 DGAC specifically identified the American Heart Association’s 1968 recommendation and the 1977
Dietary Goals for the United States, both of which recommended 300 mg/day of cholesterol.
54 Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010, pp. 225-226.
Congressional Research Service
10
The Dietary Guidelines for Americans: Overview and Considerations for Congress
pattern modeling analysis. Although the 2010 DGA recommended limiting cholesterol intake to
less than 300 mg per day, it also explained that while dietary cholesterol is associated with higher
LDL levels in certain individuals, the effect of dietary cholesterol on LDL levels is reduced when
saturated fatty acid intake is low. Furthermore, “the potential negative effects of dietary
cholesterol are relatively small compared to those of saturated and trans fatty acids.”55
Subsequent editions of the DGA have not included a quantitative intake recommendation for
cholesterol. The 2015 DGAC concluded that available evidence “shows no appreciable
relationship between consumption of dietary cholesterol and serum cholesterol.” As a result, the
committee did not recommend limiting daily cholesterol to 300 mg per day.56 Consistent with the
DGAC’s report, the 2015-2020 DGA did not include a quantitative recommendation for
cholesterol intake, explaining that although dietary patterns low in cholesterol are associated with
reduced risk of CVD and obesity, eating patterns consist of numerous interacting components.
For example, diets low in cholesterol also tend to be lower in saturated fat, which may play a
bigger role in blood cholesterol levels.57 The 2015-2020 DGA further stated that more research is
needed regarding the dose-response relationship between dietary cholesterol and blood
cholesterol, and noted a lack of sufficient evidence to recommend a quantitative limit for dietary
cholesterol.58
Similar to the 2015 DGAC, the 2020 DGAC also found insufficient evidence to determine an
independent relationship between dietary cholesterol intake in adults and blood lipids (e.g., LDL),
given the co-occurrence of cholesterol with saturated fats in foods. The 2020 DGAC did conclude
that there is strong evidence that diets lower in saturated fat and cholesterol in childhood result in
lower levels of total blood and LDL cholesterol throughout childhood, particularly for boys.59
Like the 2015-2020 DGA, the 2020-2025 DGA did not include a quantitative recommendation for
cholesterol, but it did note NASEM’s recommendation that dietary cholesterol intake be as low as
possible.60
Added Sugars
Another guideline that has been present in each version of the DGA but modified over time
concerns sugar consumption. While each of the DGA editions has recommended limiting
consumption of sugars or added sugars,61 the 2015-2020 DGA was the first to include a
quantitative limit for added sugars intake (i.e., no more than 10% of total daily calories). Prior to
that, the 2010 DGAC’s report and the 2010 DGA recommended reducing consumption of added
The 2010 DGAC reviewed the 2005 DGAC’s report and then examined the question: “What Is the Effect of Dietary
Cholesterol Intake on Risk of Cardiovascular Disease, Including Effects on Intermediate Markers Such as Serum Lipid
and Lipoprotein Levels and Inflammation?”
55 USDA and HHS, Dietary Guidelines for Americans 2010, p. 27.
56 Scientific Report of the 2015 Dietary Guidelines Advisory Committee, Part D. Chapter 1: Food and Nutrient Intakes
and Health: Current Status and Trends, p. 58.
57 HHS and USDA, Dietary Guidelines for Americans 2015–2020, pp. 32-34.
58 Ibid.
59 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part D: Chapter 9: Dietary Fats and Seafood,
p. 10.
60 USDA and HHS, Dietary Guidelines for Americans, 2020-2025, p. 44.
61 Added sugars are defined as sugars that are added to food during processing or preparation, including brown sugar,
corn sweetener, corn syrup, dextrose, fructose, fruit juice concentrates, high fructose corn syrup, and honey.
Congressional Research Service
11
The Dietary Guidelines for Americans: Overview and Considerations for Congress
sugars and explained that no more than about 5% to 15% of calories from solid fats and added
sugars combined can be reasonably accommodated in a healthy eating pattern.62
The 2015 DGAC proposed the 10% limit based on food pattern modeling, which found that when
added sugars consumption exceeds 3% to 9% of daily calories, a healthy eating pattern within
recommended calorie amounts may be hard to achieve. The 10% limit was further supported by
the scientific evidence review conducted by the committee, which found “strong and consistent
evidence” linking intake of added sugars from food and/or sugar-sweetened beverages with
excess body weight in children and adults, as well as moderate evidence from prospective cohort
studies suggesting that higher intake of added sugars is consistently associated with increased risk
of hypertension and stroke in adults, among other outcomes.63 Based on this evidence, the 20152020 DGA recommended consuming less than 10% of daily calories from added sugars.64
The 2020 DGAC revisited the topic of added sugars, examining the relationship between added
sugars and CVD and evaluating the impact of added sugars consumption on achieving nutrient
recommendations. The 2020 DGAC recommended lowering the quantitative limit for added
sugars from 10% to 6%, based on food pattern modeling, which showed that the amount of
calories “required to meet food group and nutrient needs using nutrient-dense representative
foods” makes up 85% of recommended daily calories.65 If the remaining calories are distributed
to solid fats and added sugars, based on population-level proportionate intakes, this leaves 6% of
calories for added sugars. USDA and HHS ultimately decided not to include this recommendation
in the 2020-2025, citing insufficient evidence.66
The DGA Development Process
As shown in Figure 1, the DGA development process generally involves four steps, the sequence
of which was modified for the 2020-2025 DGA: (1) establishment of an advisory committee (i.e.,
the DGAC), (2) identification of the topics and scientific questions, (3) DGAC review of the
scientific evidence and submission of its recommendations and conclusions in an advisory report
to the HHS and USDA Secretaries, and (4) development of the final DGA policy document by
HHS and USDA.67
62 Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010, p. 14. USDA
and HHS, Dietary Guidelines for Americans 2010, p. 28.
63 Scientific Report of the 2015 Dietary Guidelines Advisory Committee, Part D. Chapter 6: Cross-Cutting Topics of
Public Health Importance, pp. 342-343, 347.
64 HHS and USDA, Dietary Guidelines for Americans 2015–2020, p. xiii.
65 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part A: Executive Summary, p. 11 and Part D.
Chapter 12: Added Sugars, p. 16.
66 DGA, “USDA-HHS Response to the National Academies of Sciences, Engineering, and Medicine: Using the Dietary
Guidelines Advisory Committee’s Report to Develop the Dietary Guidelines for Americans, 2020-2025,”
https://www.dietaryguidelines.gov/about-dietary-guidelines/related-projects/usda-hhs-response-national-academiessciences-engineering.
67 The DGA website lists “implementation” as the fifth step of the DGA development process; however, for purposes
of this report, implementation of the DGA is described separately.
Congressional Research Service
12
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Figure 1. The DGA Development Process
Comparison of the 2015-2020 and 2020-2025 DGA
Source: Created by CRS based on information on dietaryguidelines.gov.
Each of these steps is described in more detail below. Where relevant, this section also discusses
recommendations made by NASEM in its two reports on the DGA development process
published in 2017 and HHS and USDA’s implementation of those recommendations in the 20202025 DGA cycle. As mentioned above, following some controversies with the 2015-2020 DGA
development process, Congress included several DGA-related policy riders in the FY2016
Consolidated Appropriations Act (P.L. 114-113) and subsequent appropriations laws.68 These
laws, among other things, directed NASEM to review the 2015-2020 DGA development process,
recommend changes, and evaluate the departments’ implementation of NASEM’s
recommendations in the development of the 2020-2025 DGA.
Certain constraints—particularly the timing of the publication of the 2017 reports relative to the
then-ongoing 2020-2025 DGA cycle—may have prevented full implementation of NASEM’s
recommendations.69 Although it appears that HHS and USDA have continued to implement some
of NASEM’s recommendations in the development of the 2025-2030 DGA (e.g., with respect to
managing conflicts of interest), the extent to which they have done so is not yet clear from
publicly available documents.
Establishment of a DGAC
Since the second edition of the DGA, a committee of nonfederal experts has been convened on a
periodic basis to help develop the DGA policy document. The DGAC historically has been
composed of nationally recognized experts in the fields of human nutrition, food science, chronic
disease prevention, and related disciplines (e.g., epidemiology, public health).
The DGAC must comply with the Federal Advisory Committee Act (FACA), which, among other
things, requires that all advisory committees be strictly advisory and prohibits advisory
committees from creating policy or issuing regulations.70 FACA requires that a charter be
68 P.L. 114-113, §735; P.L. 116-6, §766; P.L. 116-260, §796.
69 NASEM, Evaluating the Process to Develop the Dietary Guidelines for Americans, 2020-2025: Final Report, p. 66.
70 For additional information, see CRS report CRS Report R44253, Federal Advisory Committees: An Introduction and
Congressional Research Service
13
The Dietary Guidelines for Americans: Overview and Considerations for Congress
prepared and filed with Congress before a federal advisory committee can meet or take any
action.71 The charter outlines the DGAC’s charge, specific duties, and general operational
characteristics. The DGAC’s work is time-limited and terminates after delivery of its final report
to the HHS and USDA Secretaries or two years from the date the charter was filed with Congress,
whichever is earlier.72
The HHS and USDA Secretaries select committee members based on their education,
professional experience, and scientific expertise, with a goal of “establishing a diverse
membership that is reflective of the racial, ethnic, gender, and geographic diversity within the
United States.”73 DGAC nominees undergo background checks and are screened for conflicts of
interest. The HHS and USDA Secretaries review committee nominations and jointly agree on
committee membership. Individuals who are selected by the Secretaries to serve on the DGAC
are appointed as “Special Government Employees” and are subject to applicable federal ethics
rules.74
DGAC membership and the methods for selecting committee members have changed over time.
For example, the 1985 DGAC included nine members; three were representatives of HHS, three
were representatives of USDA, and three were selected from a list of nominees recommended by
the National Academy of Sciences.75 In contrast, for the 2000 DGAC, an 11-member committee
of experts was appointed after a call for nominations was published in the Federal Register.76 The
2020-2025 and 2025-2030 DGACs each included 20 members who were appointed after a call for
nominations in the Federal Register once HHS and USDA identified the topics and scientific
questions in advance and thus the expertise needed to serve on the DGAC.77
NASEM Recommendations
In its 2017 report Optimizing the Process for Establishing the Dietary Guidelines for Americans:
The Selection Process, NASEM made four recommendations with respect to establishing the
DGAC:
1. The HHS and USDA Secretaries should hire an external third party to review and
narrow the candidate pool to a list of primary and alternate nominees using
criteria developed by the departments. Based on its review of other advisory
committees, NASEM concluded that the nominee screening and the appointment
authority should be separated.
Overview.
71 Ibid.
72 See, for example, HHS, “Establishment of the 2015 Dietary Guidelines Advisory Committee,” 78 Federal Register
8147, February 5, 2013, and HHS, “Announcement of First Meeting of the 2025 Dietary Guidelines Advisory
Committee and Request for Comments,” 88 Federal Register 2423, January 19, 2023.
73
DGA, “Learn about the Process,” https://www.dietaryguidelines.gov/work-under-way/learn-about-process.
74 Ibid.
75 Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, April 10, 1985, p. iii.
76 Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2000. See also
USDA, HHS, “Invitation for Nominations for the Dietary Guidelines Advisory Committee,” 62 Federal Register
48982, September 18, 1997.
77 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, 2020 Dietary Guidelines Advisory Committee
Membership, p. 1. See also DGA, “About the Committee,” https://www.dietaryguidelines.gov/2025-advisorycommittee.
Congressional Research Service
14
The Dietary Guidelines for Americans: Overview and Considerations for Congress
2. The HHS and USDA Secretaries should make available for public comment a list
of provisional appointees to include short biographies and any known conflicts of
interest.
3. The HHS and USDA Secretaries should disclose how provisional nominees’
biases and conflicts of interest are identified and managed, including by
documenting how conflicts of interest were managed in the DGAC report.
4. The HHS and USDA Secretaries should “adopt a system for continuous process
improvement to enhance outcomes and performance” of the DGAC selection
process.
While NASEM’s 2022 reports did not evaluate whether HHS and USDA adopted the 2017
recommendations for the committee selection process, the departments addressed these
recommendations in a presentation.78 The departments did not use a third party for the 2020
DGAC selection process due to time and cost constraints, nor did the departments make public a
list of provisional appointees due to privacy concerns. HHS and USDA did develop screening
criteria that was included in the call for nominations. The departments also took steps to assess
and manage potential conflicts of interest and minimize bias, including by, for the first time,
requesting specific information in nomination packages (e.g., education, employment, peerreviewed publications, presentations, blogs, funding sources, and other affiliations).79 In addition,
individuals under final consideration for appointment to the 2020 DGAC were required to submit
a confidential financial disclosure report before being appointed. This was the first time this
review was conducted before committee appointment.80
The departments have undertaken a similar process for the appointment of the 2025 DGAC, for
example, by requiring specific information to be submitted in nomination packages and
submission of a confidential financial disclosure report prior to final appointment.81
Identification of Scientific Questions
For the 1985 through 2015-2020 editions of the DGA, establishment of the DGAC was the first
step in DGA development, preceding a selection of questions and topics for scientific review.
Typically, HHS and USDA would publish a notice in the Federal Register announcing the
departments’ intent to establish the DGAC and a request for nominations, which included a list of
the areas of expertise being considered for DGAC membership. Once appointed, each DGAC
reviewed the previous edition of the DGA and determined if, based on the current science,
78 USDA and HHS, “Responding to the National Academies of Sciences, Engineering, and Medicine Study on the
Process to Update the Dietary Guidelines for Americans,” Presentation of Eve Stoody, Designated Federal Officer for
the 2020 DGAC, https://www.dietaryguidelines.gov/sites/default/files/2019-05/
Day%201%20Response%20to%20NASEM%20Study.pdf.
79 Ibid. Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part C. Methodology, p. 8.
80 Ibid.
81 HHS, “Announcement of Intent To Establish the 2025 Dietary Guidelines Advisory Committee and Solicitation of
Nominations for Membership,” 87 Federal Register 36137, June 15, 2022. DGA, “Dietary Guidelines for Americans,
2025-2030 Development Process,” https://www.dietaryguidelines.gov/learn-about-process#step-2-appoint-theadvisory-committee.
Congressional Research Service
15
The Dietary Guidelines for Americans: Overview and Considerations for Congress
revisions were warranted.82 The DGAC, working within this broad charge, then identified the
scientific questions it would answer, with input from HHS and USDA.83
Following some controversies with the development of the 2015-2020 DGA (discussed in more
detail in the section “The 2015-2020 DGA”), the process for developing the 2020-2025 DGA was
modified so that the Secretaries of HHS and USDA identified the topics and scientific questions
for consideration before the DGAC members were selected, based on expertise in those areas.84
This was done “to promote a deliberate and transparent process, better define the expertise
needed on the Committee, and ensure the scientific review conducted by the Committee would
address Federal nutrition policy and program needs and help manage resources.”85 HHS and
USDA prioritized topics based on four criteria: relevance, importance, potential federal impact,
and avoiding duplication.86 The potential topics and supporting scientific questions identified by
HHS and USDA were published online for public comment. After HHS and USDA reviewed the
comments, the agencies announced a list of the final topics and questions, along with a call for
nominations to the 2020 DGAC.87
Similarly, for the development of the 2025-2030 DGA, HHS and USDA first selected a list of
topics and scientific questions to identify the expertise needed on the DGAC and then appointed
members accordingly.88 In identifying proposed scientific questions, HHS and USDA conducted a
yearlong process, which involved input from federal experts and a public comment period
resulting in more than 1,400 public comments.89 The departments considered the same four
criteria as for the 2020-2025 DGA (i.e., relevance, importance, potential impact to federal
programs, and avoiding duplication), as well as research availability (new to 2025).90 Additional
questions may be added to the evidence review, provided they meet the five prioritization
criteria.91
82 Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, April 1985, p. iv;
Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 1990, May 1990, p. 3;
Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 1995, September 1995,
p. 5; Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2000, June 2000,
p. viii. Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2005, August
2004, p. 20; Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010, May
2010, Part C. Methodology p. 57; Scientific Report of the 2015 Dietary Guidelines Advisory Committee, February
2015, Part C. Methodology, pp. 30-31.
83 NASEM, Redesigning the Process for Establishing the Dietary Guidelines for Americans, 2017, p. 128.
84 Charter of the 2020 DGAC, https://www.dietaryguidelines.gov/sites/default/files/2019-03/
DietaryGuidelinesAdvisoryCommitteeCharter-10-05-18.pdf.
85 USDA and HHS, Dietary Guidelines for Americans, 2020-2025, p. 8.
86 Health.gov, Call for Public Comments on Topics and Scientific Questions for the 2020-2025 Dietary Guidelines for
Americans, March 1, 2018, https://health.gov/news/news-and-announcements/2018/03/call-public-comments-topicsscientific-questions-2020-2025-dietary-guidelines-americans.
87
USDA and HHS, “Announcement of Intent To Establish the 2020 Dietary Guidelines Advisory Committee and
Solicitation of Nominations for Membership,” 83 Federal Register 45206, September 6, 2018.
88 DGA, “Dietary Guidelines for Americans, 2025-2030 Development Process,” https://www.dietaryguidelines.gov/
work-under-way/learn-about-process.
89 2025 Dietary Guidelines Advisory Committee, Meeting 1, February 9 and 10, 2023.
90 DGA, “Scientific Questions for the Dietary Guidelines for Americans, 2025-2030,”
https://www.dietaryguidelines.gov/most-popular-questions.
91 Charter of the 2025 DGAC, https://www.dietaryguidelines.gov/sites/default/files/2023-01/
2025_DGAC_Charter_Final_12.09.2022.pdf.
Congressional Research Service
16
The Dietary Guidelines for Americans: Overview and Considerations for Congress
NASEM Recommendations
NASEM’s 2017 report raised questions about the sequence of events with respect to the 2015
DGAC appointment and topic selection, as well as the process by which topics were identified
and scientific questions prioritized. With respect to the sequence of events, NASEM noted that
while the call for nominations listed in the Federal Register included the areas of expertise
considered by HHS and USDA, there was no opportunity for the public to provide input on which
areas of expertise and experience should be included.92 With respect to the process by which
topics were identified, NASEM explained that HHS and USDA have encouraged DGACs to
explore specific outcomes without justification for selecting those outcomes and with limited
public input. For example, the departments encouraged the 2015 DGAC to include topics that
have the potential to affect food- and nutrition-related health outcomes.93 Similar ambiguities
were found in the process by which the DGAC selected and prioritized scientific questions. The
NASEM report noted that “this lack of public input into the process for selecting topics and
questions to address does not take full advantage of expertise within the nutrition community,
thus creating the possibility of subject matter imbalance in the composition of the DGA.”94
In its 2017 reports, NASEM did not include, as one of its recommendations, modifying the
sequence of events with respect to DGAC appointment and topic selection. However, as
discussed in the next section, NASEM did recommend redistributing the DGAC’s functions
across three new committees, including the Dietary Guidelines Planning and Continuity Group,
which would be responsible for monitoring and curating evidence to identify and prioritize topics
for inclusion in the DGA, and would provide strategic planning support across DGA cycles.
DGAC Review of the Evidence
Once DGAC members are appointed by the USDA and HHS Secretaries, they conduct a review
of the scientific evidence to develop their conclusions and recommendations, which are then
submitted in an advisory report to the Secretaries. Each DGAC since 1985 has submitted an
advisory report to the HHS and USDA Secretaries.95 (The section “Changes in Methods for
Reviewing the Evidence” provides more information about the methods used by DGACs over
time to review the scientific evidence.)
To accomplish the committee’s charge, DGAC members generally work within subcommittees,
which meet regularly to review evidence for the identified scientific topics and questions. The
2020 DGAC, for example, had six topic area subcommittees (i.e., Pregnancy and Lactation, Birth
to 24 Months, Dietary Patterns, Dietary Fats and Seafood, Beverages and Added Sugars, and
Frequency of Eating), as well as one cross-cutting working group (Data Analysis and Food
92 NASEM, Redesigning the Process for Establishing the Dietary Guidelines for Americans, 2017, p. 128.
93 Ibid.
94 Ibid.
95 Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, April 1985; Report
of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 1990, May 1990; Report of the
Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 1995, September 1995; Report of the
Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2000, June 2000; Report of the
Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2005, August 2004; Report of the
Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010, May 2010; Scientific Report of
the 2015 Dietary Guidelines Advisory Committee, February 2015; Scientific Report of the 2020 Dietary Guidelines
Advisory Committee, July 2020.
Congressional Research Service
17
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Pattern Modeling), that corresponded to the topics and questions identified by HHS and USDA.96
The subcommittee meetings generally have not been open to the public.
At times, DGACs have enlisted the expertise of individuals not appointed to the committee. For
example, the 2015 DGAC, for the first time, used outside consultants to assist with its evidence
review.97 Two subcommittees of the 2015 DGAC—the Diet and Physical Activity Behavior
Change subcommittee and the Food Sustainability and Safety Committee—used outside
consultants, and seven outside experts were invited to present to the full DGAC at two public
meetings.98 The 2015 DGAC’s charter explicitly allowed for use of nonmember special
consultants and/or individuals with certain expertise.99 While consultants are vetted for financial
conflicts of interests and do not vote on DGAC decisions, their use may have raised questions
about the integrity of the DGAC’s review process.100 In contrast to the 2015 DGAC, outside
consultants were not used by the 2020 DGAC. For development of the 2025-2030 DGA, the
departments also identified the topics and scientific questions prior to DGAC appointment.101
As mentioned above, each DGAC has been established for a time-limited term during which the
committee evaluates the science and develops conclusions and recommendations to inform the
development of the DGA. The DGAC’s subcommittees and the full committee meet throughout
the duration of its appointment. Full committee meetings are available to the public, and
throughout the DGAC’s review of the scientific evidence and data, the public can submit
comments in response to the questions and topics being examined. For the first time, the 20202025 DGAC held a public meeting to discuss its draft advisory report one month before the final
advisory report was posted for public comment.102
NASEM Recommendations
In its 2017 report, NASEM found that the current DGA development process, which provides two
years for DGAC’s work and one year for HHS and USDA to develop the policy document, results
in two years of “relative inactivity.”103 NASEM stated “that using the entire 5 years for work on
the DGA will not only provide the opportunity for a more thorough evaluation of the science, but
also allow the DGA process to become more agile, flexible, and effective—and will address more
topics of interest to the general public.”104 In this context, NASEM recommended that the HHS
and USDA Secretaries should redesign the DGA process so that the work occurs over all five
years. NASEM also recommended that HHS and USDA prioritize the topics to be reviewed in
each DGA cycle and redistribute the DGAC’s functions to three separate groups:
A Dietary Guidelines Planning and Continuity Group to monitor and curate
evidence to identify and prioritize topics for inclusion in the DGA, and to provide
strategic planning support across DGA cycles.
96 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part C. Methodology, p. 9.
97 NASEM, Redesigning the Process for Establishing the Dietary Guidelines for Americans, 2017, pp. 128-129.
98 Scientific Report of the 2015 Dietary Guidelines Advisory Committee, Part C. Methodology, pp. 32-33.
99 Charter of the 2015 DGAC, https://web.archive.org/web/20150918165215/http://health.gov/dietaryguidelines/2015-
BINDER/meeting1/docs/fedDocumentation/dgac2015-charter-final.pdf.
100 NASEM, Redesigning the Process for Establishing the Dietary Guidelines for Americans, 2017, pp. 128-129.
101 DGA, “Work Under Way,” https://www.dietaryguidelines.gov/work-under-way/learn-about-process.
102 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part C. Methodology, p. 8.
103 NASEM, Redesigning the Process for Establishing the Dietary Guidelines for Americans, 2017, preface x.
104 Ibid.
Congressional Research Service
18
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Technical expert panels to provide content and methodological consultation
during evaluation of the evidence.
A Dietary Guidelines Scientific Advisory Committee to interpret the scientific
evidence and draw conclusions.105
In its 2022 final report, NASEM concluded that HHS and USDA did not implement the major
elements of this recommendation for the 2020-2025 DGA because the departments did not
redistribute the functions of the DGAC to three separate groups. However, HHS and USDA did
make certain changes to the DGA development process that “partially met the intent of
redistributing some of the functions of the DGAC,” specifically the interpretation and integration
of the data.106
In its 2017 report, NASEM also made several recommendations with respect to the DGAC’s
review of the evidence. For example, with respect to use of the NESR, NASEM recommended
that the HHS and USDA Secretaries clearly separate the roles of the NESR and the proposed
Dietary Guidelines Scientific Advisory Committee, and that NESR systematic reviews be
externally peer reviewed prior to being made available for use by the proposed Dietary
Guidelines Scientific Advisory Committee. In its 2022 report, NASEM found that this
recommendation was partially implemented for the 2020-2025 DGA; the roles of DGAC and
NESR were defined, but some tasks were shared between the two groups, and the peer review
was not external to the federal government (i.e., federal scientists peer reviewed the systematic
reviews rather than outside experts).107 NASEM also recommended that the USDA Secretary
ensure that NESR systematic reviews align with best practices by conducting ongoing training of
the NESR staff; engaging with experts to periodically review NESR’s methods, as well as with
external groups on the forefront of systematic review methods; and investing in technological
infrastructure. NASEM found that HHS and USDA substantially implemented this
recommendation.108
Relatedly, NASEM recommended that HHS and USDA should “enhance food pattern modeling
to better reflect the complex interactions involved, variability in intakes, and range of possible
healthful diets,” and that HHS and USDA should standardize criteria for determining which
nutrients are determined by the DGAC to be of public health concern.109 In its 2022 report,
NASEM concluded that some “refinements” were made to the food pattern modeling used to
develop the 2020-2025 DGA, but the analytic methods did not change.110 With respect to
standardization of criteria, HHS and USDA did implement this recommendation by developing a
framework that standardized terminology, thresholds, analytic methods, and interpretations
related to nutrients of concern.111
105 Ibid., pp. 8-12.
106 NASEM, Evaluating the Process to Develop the Dietary Guidelines for Americans, 2020-2025: Final Report, pp. 5-
7.
107 Ibid., pp. 9-10.
108 Ibid.
109 NASEM, Redesigning the Process for Establishing the Dietary Guidelines for Americans, 2017, pp. 13-15.
110 Ibid.
111 NASEM, Evaluating the Process to Develop the Dietary Guidelines for Americans, 2020-2025: Final Report, p. 11.
Congressional Research Service
19
The Dietary Guidelines for Americans: Overview and Considerations for Congress
HHS and USDA Develop the DGA
The Secretaries of HHS and USDA consider the DGAC’s report, as well as comments on the
report from the public and federal agencies, to draft the DGA policy document. The DGAC’s
report is solely advisory, and DGAC’s conclusions and recommendations are not always included
in the DGA. The DGA must be “based on the preponderance of the scientific and medical
knowledge which is current at the time the [DGA] is prepared.”112 As such, in writing the DGA,
HHS and USDA work to ensure that the final policy document meets this standard and that it is
not based on an individual study or opinion.113
The DGA is drafted by the DGA writing team, which is made up of HHS and USDA staff,
including nutrition scientists with expertise in the DGA and related research and programs, as
well as those with expertise in communicating nutrition information. The writing team is guided
by several “key tenets,” including that the recommendations in the final policy document are
based on the totality of the evidence, that they address the needs of federal programs, and that
they incorporate plain language strategies. The DGA writing team also follows best practices
established by other organizations that provide population-wide health guidance. These best
practices include supporting transparency, managing conflicts of interest, and involving key
stakeholders, among others.114
Once written, the draft DGA document goes through a three-step review process:
1. Federal expert technical review. The draft document is subject to a technical
review by federal scientists, including those who supported the DGAC’s work.
2. External peer review. The draft document goes through external peer review by
outside experts, including former DGAC members.
3. Departmental clearance. This process varies depending on the procedures for
HHS and USDA at the time of review. However, it typically involves two parts:
(1) agency review and (2) Administration review. During agency review, the
agencies within HHS and USDA with nutrition expertise—typically the agency
directors or administrators and subject matter experts—participate in the
clearance process. If substantive revisions are made, additional review and
clearance may be necessary. The Administration review process typically
involves formal review of the draft by the Office of the USDA Under Secretary
of Food, Nutrition, and Consumer Services; the USDA Under Secretary of
Research, Education, and Economics; the HHS Assistant Secretary for Health;
staff from the Offices of the USDA and HHS Secretaries; and departmental
communications and government relations staff. A decision memorandum is then
routed through each department to the HHS and USDA Secretaries, who are
responsible for granting final approval to the document. Once approved, the
DGA is released.115
112 P.L. 101-445, §301(a)(2).
113 DGA, “USDA-HHS Development of the Dietary Guidelines,” https://www.dietaryguidelines.gov/usda-hhs-
development-dietary-guidelines.
114 Ibid.
115 DGA, Current Dietary Guidelines, “Review Process,” https://www.dietaryguidelines.gov/usda-hhs-developmentdietary-guidelines#reviewprocess.
Congressional Research Service
20
The Dietary Guidelines for Americans: Overview and Considerations for Congress
NASEM Recommendations
To increase transparency in the DGA development process, NASEM recommended that USDA
and HHS provide a clear explanation when recommendations made by the DGAC are “accepted,
revised, or discarded.”116 NASEM found that this recommendation was substantially
implemented by the departments for the 2020-2025 DGA.117 For example, the 2020 DGAC report
recommended reducing the quantitative limit for added sugars from 10% to 6% and limiting
alcoholic drinks to one drink per day for both men and women (as opposed to two drinks for
men). HHS and USDA noted that although evidence supports limiting intake of added sugars and
alcoholic beverages, the 2020-2025 DGA did not include changes to the quantitative limits
suggested by the DGAC because such changes were not supported by a preponderance of the
evidence.118
Examples of Implementation of the DGA
The National Nutrition and Related Research Monitoring Act of 1990 requires that federal
agencies promote the DGA in carrying out any federal food, nutrition, or health program.119 This
section provides examples of how two federal agencies—the Food and Drug Administration
(FDA) and USDA—have implemented DGA recommendations and used the policy document to
establish nutrition policies.
FDA and Nutrition Labeling
The Federal Food, Drug, and Cosmetic Act authorizes FDA to regulate nutrition labeling and
health claims on food labels. FDA uses the DGA, in addition to other consensus reports and
scientific information, in establishing nutrition labeling requirements.120 For example, FDA has
used the DGA to support requiring disclosure of added sugars on the Nutrition Facts panel and to
set a Daily Reference Value (DRV) for added sugars. Specifically, in 2014, FDA issued two
proposed rules, which were finalized in 2016, to update the Nutrition Facts panel to better align
with the 2010 DGA, including a key recommendation to reduce consumption of added sugars.
One of the agency’s final rules required, among other things, a new “added sugars” line on the
Nutrition Facts panel distinguishing between added sugars and naturally occurring sugars in a
food.121
While the 2010 DGA did not specify a quantitative limit for added sugars, the 2015 DGAC’s
report provided new scientific evidence to support establishing a reference amount for added
sugar intake. The 2015 DGAC recommended that added sugars should not contribute more than
116 NASEM, Redesigning the Process for Establishing the Dietary Guidelines for Americans, 2017, p. 50.
117 NASEM, Evaluating the Process to Develop the Dietary Guidelines for Americans, 2020-2025: Final Report, pp. 7-
8.
118 DGA, “USDA-HHS Response to the National Academies of Sciences, Engineering, and Medicine: Using the
Dietary Guidelines Advisory Committee’s Report to Develop the Dietary Guidelines for Americans, 2020-2025,”
https://www.dietaryguidelines.gov/about-dietary-guidelines/related-projects/usda-hhs-response-national-academiessciences-engineering.
119 P.L. 101-445 §301(a).
120 FDA, “Food Labeling: Nutrient Content Claims; Definition of Term ‘Healthy,’” 87 Federal Register 59171,
September 29, 2022.
121 FDA, “Food Labeling: Revision of the Nutrition and Supplement Facts Labels,” 81 Federal Register 33741, May
27, 2016. 21 C.F.R. 101.9
Congressional Research Service
21
The Dietary Guidelines for Americans: Overview and Considerations for Congress
10% of total daily calories, a recommendation that was ultimately included in the 2015-2020
DGA. In light of this new evidence, FDA established a DRV of 10% of total calorie intake from
added sugars.122
Another example of how FDA has used the DGA to inform nutrition labeling requirements is
through its proposal to modify the regulatory definition of the term healthy, an implied nutrition
content claim. In order for a food to be labeled as healthy, it must meet certain criteria specified
in FDA regulations. The definition, as codified in 1994, includes limits on total fat, saturated fat,
cholesterol, and sodium, and includes minimum amounts for vitamin A, vitamin C, iron, calcium,
protein, and dietary fiber.123 On September 29, 2022, FDA issued a proposed rule to update the
regulatory definition of “healthy” so that it better aligns with current nutrition science and the
2020-2025 DGA.124
As explained in FDA’s proposed rule, the 1994 definition of healthy is based solely on individual
nutrients because at the time the regulation was issued, nutrition science and federal nutrition
guidance focused on individual nutrients in food. However, the DGA now focuses largely on
dietary patterns rather than individual nutrients, with some exceptions (i.e., recommending limits
on sodium, added sugars, and saturated fat). In addition, among other changes, the DGA no
longer recommends diets low in total fat, but rather recommends decreasing intake of saturated
fat while increasing intake of mono- and poly-unsaturated fats. The DGA also recommends
limiting intake of added sugars to less than 10% of total daily calories. Because of these changes,
the current definition of healthy is inconsistent with the DGA and current nutrition science. For
example, under the 1994 definition, certain nutrient-dense foods are not permitted to be labeled as
healthy (e.g., salmon due to fat content), while other foods that contain high amounts of added
sugar could be labeled as healthy (e.g., certain breakfast cereals). Given this, FDA has proposed
to revise the definition of healthy to require that food products contain a certain amount of food
from at least one of the food groups or subgroups recommended by the 2020-2025 DGA (i.e.,
vegetables, fruits, grains, dairy, and protein foods, and oils) and be limited in sodium, saturated
fat, and added sugars.125
USDA and School Meal Programs
The DGAs inform the nutritional guidelines of several programs administered by USDA. For
example, the Richard B. Russell National School Lunch Act requires that federally funded school
meals reflect the latest DGA.126 In January 2012, following enactment of the Healthy HungerFree Kids Act of 2010, USDA promulgated a final rule updating the meal and nutrition standards
for the National School Lunch Program (NSLP) and the School Breakfast Program (SBP) to align
with the 2010 DGA and NASEM recommendations.127 Among other things, the final rule
established vegetables as their own meal component, separate from fruits, in the NSLP and
122 Ibid. In a 2,000 calorie per day diet, 10% equates to 200 calories from added sugar or about 50 grams of added sugar
(there are 4 calories in a gram of sugar) or 12.5 teaspoons of added sugar.
123 21 C.F.R. 101.65(d)(2).
124 FDA, “Food Labeling: Nutrient Content Claims; Definition of Term ‘Healthy,’” 87 Federal Register 59168,
September 29, 2022.
125 Ibid.
126 42 U.S.C. 1758(a)(4) Section 9(a)(4). Also see 42 U.S.C. 1753(b)(3); Section 4(b)(3) and Section 10 of the Child
Nutrition Act of 1966.
127 USDA, “Nutrition Standards in the National School Lunch and School Breakfast Programs,” 77 Federal Register
4088, January 26, 2012.
Congressional Research Service
22
The Dietary Guidelines for Americans: Overview and Considerations for Congress
required that all vegetable subgroups specified in the 2010 DGA (e.g., dark green, orange, and
legumes) be offered over the course of a week. The rule also restricted grains to only those that
are “whole grain-rich” and restricted milk to unflavored low-fat (1%) and flavored and
unflavored fat-free varieties (subsequent law and rulemaking have altered certain aspects of the
2012 standards, including the whole-grain and milk requirements).128
Not every iteration of the DGA results in major changes to the school meal program and nutrition
standards. For example, following the release of the 2015-2020 DGA, USDA determined that
NSLP and SBP competitive foods (i.e., foods and beverages sold in schools during the school day,
such as in vending machines or a la carte in the cafeteria) standards did not need to be modified
as they were already consistent with the 2015-2020 DGA.129 In 2018, the agency made changes to
sodium, milk, and whole grain requirements “to ensure that school meals regulations work for all
operators, while reflecting the recommendations of the Dietary Guidelines for Americans.”130
In February 2023, USDA issued a proposed rule that would make several changes to school
nutrition standards, in part, to better align with the 2020-2025 DGA.131 Among other things, the
proposed rule includes product-specific and weekly (less than 10% of calories) added sugars
limits for school meals. For example, breakfast cereals would be limited to no more than 6 grams
of added sugars per dry ounce, and yogurt would be limited to no more than 12 grams of added
sugars per 6 ounces.132
Controversies in the DGA
Due to its impact on federal nutrition policy and consumer choices, the DGA is of interest to
public health, nutrition, agriculture, and food industry stakeholders who are given opportunities to
provide input throughout the DGA development process. In some years, stakeholders and
policymakers have opposed various aspects of the DGA development process, for example, the
composition of the DGAC, the scope of the DGAC’s recommendations, the evidence used by the
DGAC to make its recommendations, and the departments’ adoption of the DGAC’s
recommendations. This section discusses some of these issues in the context of the 2015-2020
and 2020-2025 DGA cycles.
The 2015-2020 DGA
After publication of the 2015 DGAC’s report, some stakeholders and policymakers argued that
the DGAC exceeded the scope of its charter by making certain policy recommendations about the
environment and sustainability, as well as economic and tax policies. Specifically, the 2015
DGAC’s report suggested that individuals should eat less red and processed meat in favor of a
plant-based diet, as “a diet higher in plant-based foods, such as vegetables, fruits, whole grains,
128 For more information on changes to nutrition standards for school meals, see CRS Report R46234, School Meals
and Other Child Nutrition Programs: Background and Funding, by Kara Clifford Billings.
129 USDA, “National School Lunch Program and School Breakfast Program: Nutrition Standards for All Foods Sold in
School as Required by the Healthy, Hunger-Free Kids Act of 2010,” 81 Federal Register 50131, July 29, 2016.
130 USDA, “Child Nutrition Programs: Flexibilities for Milk, Whole Grains, and Sodium Requirements,” 83 Federal
Register 63775, December 12, 2018.
131 USDA, “USDA Announces Steps to Improve Child Health through Nutritious School Meals,” February 3, 2023,
https://www.fns.usda.gov/news-item/usda-0027.23.
132 USDA, “Child Nutrition Programs: Transitional Standards for Milk, Whole Grains, and Sodium,” 87 Federal
Register 6984 February 7, 2023.
Congressional Research Service
23
The Dietary Guidelines for Americans: Overview and Considerations for Congress
legumes, nuts, and seeds, and lower in calories and animal-based foods is more health promoting
and is associated with less environmental impact than is the current U.S. diet.”133 The DGAC
added that due to high consumption of animal-based foods (e.g., meat, eggs, and dairy products)
and low intake of plant-based foods, the average U.S. diet may have a large impact on the
environment in terms of increased greenhouse gas emissions, land use, water use, and energy use.
The DGAC also proposed use of economic and tax policies to encourage the production and
consumption of healthy foods and to reduce consumption of unhealthy foods (e.g., by taxing
sugar-sweetened beverages, snack foods, and desserts, and by restricting marketing of certain
foods to children and teens).134
In response, some Members of Congress wrote that the DGAC “had neither the expertise,
evidence, nor charter” to make recommendations about matters of sustainability and tax policy,135
which was reiterated by meat trade groups.136 Some observers supported the discussion
surrounding sustainability, saying that it is important to have an understanding of how food
production affects the environment.137 Ultimately, the HHS and USDA Secretaries determined
that issues of sustainability and tax policy would not be part of the final policy document and that
the DGA would “remain within the scope of our mandate in the 1990 National Nutrition
Monitoring and Related Research Act (P.L. 101-445, NNMRRA), which is to provide ‘nutritional
and dietary information and guidelines’ ... ‘based on the preponderance of the scientific and
medical knowledge.’”138
Stakeholders also expressed concern with the 2015 DGAC’s evidentiary review process, in
particular its reliance on existing systematic reviews and observational studies. The 2015 DGAC
used the NESR to answer approximately 27% of its questions, relying on existing sources of
evidence (e.g., existing reports and systematic reviews) to answer another 45%, and data analyses
and food pattern modeling analyses to answer an additional 30%.139 This approach is in contrast
to the 2010 DGAC, which used the NESR to answer the majority of its research questions.140
According to the 2015 DGAC, the majority of the scientific community now regularly uses
systematic reviews, so unlike the 2010 DGAC, the 2015 DGAC relied more heavily on existing
sources of evidence (e.g., existing systematic reviews, meta-analyses, and reports) and avoided
duplicative efforts.141 This approach of using existing systematic reviews was subject to criticism,
with some questioning the scientific rigor and objectivity of the advisory report. For example,
some argued that the 2015 DGAC bypassed the NESR process for certain issues (e.g., added
133 Scientific Report of the 2015 Dietary Guidelines Advisory Committee, Part A. Executive Summary, p. 5.
134 Scientific Report of the 2015 Dietary Guidelines Advisory Committee, Part D. Chapter 6: Cross-Cutting Topics of
Public Health Importance, p. 347.
135 Letter from various Members of Congress to Secretaries Vilsack and Burwell, March 31, 2015,
https://agriculture.house.gov/uploadedfiles/ag_dietaryguidelineslettertosecsvilsackburwell.pdf.
136 CRS Report R44360, Dietary Guidelines for Americans: Frequently Asked Questions, by Agata Bodie.
137 A Aubrey, “New Dietary Guidelines Will not Include Sustainability Goal,” NPR, October 13, 2015,
http://www.npr.org/sections/thesalt/2015/10/06/446369955/new-dietary-guidelines-will-not-include-sustainability-goal.
138 Secretaries Vilsack and Burwell, “2015 Dietary Guidelines: Giving You the Tools You Need to Make Healthy
Choices,” USDA blog, October 6, 2015, https://www.usda.gov/media/blog/2015/10/06/2015-dietary-guidelines-givingyou-tools-you-need-make-healthy-choices.
139 Scientific Report of the 2015 Dietary Guidelines Advisory Committee, Part C. Methodology, p. 32. The percentages
do not add to 100% due to rounding.
140 Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010, Part A:
Executive Summary, p. 1.
141 Scientific Report of the 2015 Dietary Guidelines Advisory Committee, Part C. Methodology, p. 32.
Congressional Research Service
24
The Dietary Guidelines for Americans: Overview and Considerations for Congress
sugars) and “almost solely used pre-existing and hand-picked systematic reviews.”142 Others
voiced concern that the 2015 DGAC relied heavily on weaker forms of science, such as
observational evidence rather than the whole body of evidence.143
The 2020-2025 DGA
One issue identified with the 2020-2025 DGA cycle was the composition of the DGAC and, more
specifically, members with perceived conflicts of interest. For example, one study published in
the journal Public Health Nutrition found that 19 of the 20 DGAC members had conflicts of
interest with the food and/or pharmaceutical industry, with the most common type of conflict
being research funding, followed by DGAC members’ presence on a board or committee in a
company, and consultant positions.144 Other stakeholders have expressed similar concerns about
the role of industry in the DGA development process, including by nominating DGAC members
with ties to the food and beverage industry.145 NASEM’s 2017 report on the DGAC selection
process included recommendations to HHS and USDA for managing biases and conflicts of
interest in the DGAC. However, in NASEM’s report, the ad hoc committee also noted that it
“does not believe these influences can be eliminated entirely” and “those who have had
relationships with industry or issue-specific advocates in the recent past could participate fairly
on a panel if the nature of the relationship was incidental to the work of the panel.”146
Another area of controversy arose in the 2020 DGA development process: the DGAC’s
recommendations to lower the recommended quantitative limits for added sugars and alcohol, and
the departments’ decision not to adopt those recommendations. Specifically, the 2020 DGAC
recommended that for men who consume alcohol, the daily limit be reduced from two drinks to
one drink. (The DGAC found that the existing recommended daily limit of one drink for women
was reasonable.) The DGAC concluded, based on a NESR systematic review, that “moderate
evidence indicates that higher average alcohol consumption is associated with an increased risk of
all-cause mortality compared with lower average alcohol consumption among those who
drink.”147 For added sugars, the DGAC recommended that the daily limit be reduced from 10% to
6%. This recommendation was based on food pattern modeling, which found that a diet could
accommodate 6% or less of calories from added sugars if it were to provide recommended
nutrient levels and remain within most of the recommended total daily calorie ranges.148 In
addition, the 2015 and 2020 DGAC’s evidence reviews suggested that added sugars may
contribute to overweight and diet-related chronic diseases.149 Members of the DGAC further
142 CRS Report R44360, Dietary Guidelines for Americans: Frequently Asked Questions, by Agata Bodie.
143 Ibid.
144 M. Mialon, P. Serodio, E. Crosbie, et al., “Conflicts of Interest for Members of the U.S. 2020 Dietary Guidelines
Advisory Committee,” Public Health Nutrition, March 2022.
145 D. Flynn, “A Second Study Finds Dietary Guidelines Panel Rife with Conflicts of Interest,” Food Safety News,
April 6, 2022, https://www.foodsafetynews.com/2022/04/a-second-study-finds-dietary-guidelines-panel-rife-withconflicts-of-interest/.
146 NASEM, Optimizing the Process for Establishing the Dietary Guidelines for Americans: The Selection Process,
2017, pp. 9-10.
147 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part D: Chapter 11: Alcoholic Beverages, p.
11.
148 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part D: Chapter 12: Added Sugars, pp. 16 to
18. For the highest daily calorie levels (i.e., 3,000 to 3,200), a diet could accommodate 7% to 8% of calories from
added sugars.
149 Ibid., pp. 22-24. Scientific Report of the 2015 Dietary Guidelines Advisory Committee, Part D. Chapter 6: Cross-
Congressional Research Service
25
The Dietary Guidelines for Americans: Overview and Considerations for Congress
explained in a separate publication that the theme of the 2020-2025 DGA was “make every bite
count,” and that alcohol and added sugars have no nutritional value.150 HHS and USDA
ultimately decided not to adopt these two recommendations, stating that although the
preponderance of the evidence supported limiting intake of alcohol and added sugars, it did not
support changes to the daily limits for alcohol and added sugars.151 The departments did clarify,
as recommended in the DGAC’s report, that drink limits are based on consumption per drinking
day rather than average amounts over time (e.g., one drink per day rather than seven drinks on
one day of the week).152 Some observers criticized the agencies for not adopting the revised
recommendations on added sugars and alcohol and for reverting to the previous
recommendations.153
The DGA and the Health of the U.S. Population
Although the DGA has become increasingly evidence-based over time, experts have noted that
the diet quality of the U.S. population has not noticeably improved since the DGA was first
introduced to consumers in 1980.154 One measure of diet quality, the Healthy Eating Index (HEI),
which is used to assess how well U.S. diets align with the DGA, indicates that Americans are not
meeting dietary recommendations.155 The HEI has a total possible score ranging from zero to 100,
with a higher score indicating better adherence to the DGA. The average HEI-2015 score for
2017-2018 (the most recent data available) is 58 out of 100, indicating that the average American
diet does not comply with the 2015-2020 DGA. Scores vary by age, with children 2 to 4 years of
age having the highest diet quality (HEI score of 62), followed by older adults aged 60 and older
(HEI score of 61).156
Cutting Topics of Public Health Importance, pp. 342-345.
150 E. Mayer-Davis, T. Naimi, and Richard Mattes, “Proposed Reductions in Limits on Added Sugar and Alcohol for
the New Dietary Guidelines: Our Perspective,” American Journal of Clinical Nutrition, 2021, vol. 114, pp. 405-406.
151 DGA, “USDA-HHS Response to the National Academies of Sciences, Engineering, and Medicine: Using the
Dietary Guidelines Advisory Committee’s Report to Develop the Dietary Guidelines for Americans, 2020-2025,”
https://www.dietaryguidelines.gov/about-dietary-guidelines/related-projects/usda-hhs-response-national-academiessciences-engineering.
152 Ibid. Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part D: Chapter 11: Alcoholic
Beverages, pp. 22-24.
153 See, for example, R. Rabin, “U.S. Diet Guidelines Sidestep Scientific Advice to Cut Sugar and Alcohol,” New York
Times, December 29, 2020, NASEM 2022, pp. 26-27.
154 S. Rowe, N. Alexander, N. Almeida, et al., “Translating the Dietary Guidelines for Americans 2010 to Bring about
Real Behavior Change,” Journal of the Academy of Nutrition and Dietetics, 2011, vol. 111, no. 1, pp. 28-39.
155 The HEI was developed in 1995 and has been modified over time to reflect each edition of the DGA. For example,
the HEI-2015 measures adherence to the 2015-2020 DGA and is the most recent measure available. A new HEI is
being developed for children under two years of age. HEI scores are calculated by nutritionists at USDA’s CNPP using
data from What We Eat in America, the interview component of NHANES. Each HEI also includes dietary
components (e.g., total sodium intake, fruit consumption), which are scored from zero to 10. The number of dietary
components differs across the different HEIs. For example, the HEI-1995 included 10 dietary components, while the
HEI-2015 includes 13 dietary components. See https://www.fns.usda.gov/hei-scores-americans.
156 USDA, “HEI Scores for Americans,” https://www.fns.usda.gov/hei-scores-americans.
Congressional Research Service
26
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Figure 2. Healthy Eating Index (HEI)-2015 Scores 2005-2018
Based on NHANES WWEIA Data
Source: Created by CRS based on USDA and HHS, Dietary Guidelines for Americans, 2020-2025, p. 4, and USDA,
“HEI Scores for Americans,” https://www.fns.usda.gov/hei-scores-americans.
Notes: The 2005-2006 through 2015-2016 numbers are from Figure I-1 in the 2020-2025 DGA and are based
on an analysis of What We Eat in American (WWEIA), the dietary component of the National Health and
Nutrition Examination Survey (NHANES). The 2017-2018 scores are from the USDA website at
https://www.fns.usda.gov/hei-scores-americans. The HEI scores were derived using the HEI-2015, thus measuring
adherence to the 2015-2020 DGA. USDA’s website includes HEI scores for earlier years. For example, the first
HEI scores available are for 1989 and 1990—both 64—which were derived using the HEI-1995. HEI scores over
time have been derived using different versions of the HEI (e.g., the HEI-1995, which included 10 dietary
components, versus the HEI-2015, which includes 13 dietary components), thus making comparisons in scores
over time challenging.
Observers have proposed various reasons as to why the DGA has not noticeably improved diet
quality in the United States, including the need for more effective communication of dietary
recommendations and changes to the food environment, and public distrust in nutrition science.
These three proposed reasons are discussed in more detail below.
Communication of Dietary Recommendations
The DGA is written for a professional audience responsible for translating and implementing the
guidelines for the U.S. population. Some stakeholders have proposed that better “integration and
translation of the evidence” is needed to bring about behavior change, for example, through
consumer education.157 In May 2021, the Institute of Food Technologists, with the Department of
Food Science at the University of Massachusetts at Amherst, held a virtual meeting with a goal of
improving implementation and adoption of the DGA.158 The meeting was funded by the USDA
National Institute of Food and Agriculture and resulted in four recommendations for improving
adoption of and adherence to the DGA. These recommendations focused on improving consumer
education and communication.159
157 S. Rowe, N. Alexander, N. Almeida, et al., “Translating the Dietary Guidelines for Americans 2010 to Bring about
Real Behavior Change,” Journal of the Academy of Nutrition and Dietetics, 2011, vol. 111, no. 1, pp. 28-39.
158 L. Sanders, J. Allen, Jeanne Blankenship, et al., “Implementing the 2020-2025 Dietary Guidelines for Americans:
Recommendations for a Path Forward,” Current Developments in Nutrition, December 2021, vol. 5, no. 12.
159 Ibid.
Congressional Research Service
27
The Dietary Guidelines for Americans: Overview and Considerations for Congress
The USDA has created several educational tools to help translate the DGA into actionable
consumer messages, for example, the Food Guide Pyramid, MyPyramid, and MyPlate (see
Figure 3). The Food Guide Pyramid was created in 1992 based on the 1990 DGA. It included six
food groups, with proportionality conveyed by the size of the section in the pyramid and with the
recommended serving amounts listed.160 In 2005, USDA modified the figure to better align with
the DGA. Renamed MyPyramid, the new figure included an image of a person walking up the
steps of the pyramid to emphasize the inclusion of physical activity. MyPyramid also included six
food groups, but in contrast to the Food Guide Pyramid, the food groups were depicted in
ascending vertical bands that reflected the recommended proportions, with quantities provided in
cups and ounces rather than servings. In 2011, USDA replaced MyPyramid with MyPlate to help
consumers visualize how to build a plate that aligns with the DGA.161 The icon—a plate on a
placemat—shows five food groups and their suggested portions.
Figure 3. Nutrition Education Tools
Source: USDA.
Some research suggests that use of nutrition education tools may help consumers achieve more
healthy dietary intakes. For example, one study evaluated the relationship between use of
MyPyramid and MyPlate and dietary intake in NHANES participants. The authors found that the
reported use of these tools was associated with more healthful dietary intakes, specifically higher
consumption of dark and leafy vegetables and lower consumption of refined grains, added sugars,
solid fats, and sodium, as well as lower overall calorie intake compared with nonusers.162 These
findings suggest that use of such educational tools may help consumers better align their diets
with the DGA.
Another consumer education tool—point-of-purchase labeling (e.g., the Nutrition Facts Panel on
packaged food, calorie disclosure on menus, and front-of-package labeling)—may also help
consumers improve their diet quality. In recent years, FDA has revised the Nutrition Facts Panel
to improve its content and design to make important information more prominent and easier to
understand. FDA also issued new menu calorie labeling regulations to aid consumers when eating
160 C. Davis and E. Altos, “Dietary Recommendations and How They Have Changed Over Time,” in America’s Eating
Habits: Changes and Consequences, Agriculture Information Bulletin No. 750, (1999, Washington, DC; Economic
Research Service, USDA), pp. 43-44.
161 USDA, “USDA’s MyPlate Celebrates Its First Anniversary,” May 30, 2012, https://www.usda.gov/media/pressreleases/2012/05/30/usdas-myplate-celebrates-its-first-anniversary.
162 J. Schwartz and J. Vernarelli, “Assessing the Public’s Comprehension of Dietary Guidelines: Use of MyPyramid or
MyPlate is Associated with Healthier Diets among US Adults,” Journal of the Academy of Nutrition and Dietetics,
2019, vol. 119, no. 3, pp. 482-489.
Congressional Research Service
28
The Dietary Guidelines for Americans: Overview and Considerations for Congress
at restaurants and other food establishments. The agency has proposed other changes to help
consumers make food choices that better align with the DGA (e.g., redefining the term healthy).
Some observers describe nutrition education and point-of-purchase labeling as “soft” policies that
place most of the responsibility on the individual consumer.163 These observers further note that
the effectiveness of such policies has varied but can be valuable as part of a broader government
food and nutrition strategy, including fiscal incentives (e.g., subsidies for fruits and vegetables)
and disincentives (e.g., taxes on sugar-sweetened beverages), which have more consistent
evidence of effectiveness but may be more challenging politically.164
Access to Healthy Food and the Food Environment
Poor diet quality and negative health outcomes have also been attributed to the food
environment.165 For example, studies have found that the presence of supermarkets and other
sources of fruits and vegetables is associated with lower BMI, especially for low-income
Americans, while lack of or long distances to supermarkets is associated with higher BMI.166
Recent editions of the DGA have recognized the role of the food environment in influencing the
nutrition decisions individuals make. The 2010 and 2015-2020 DGA described the socialecological model, which provides a framework for how the different elements in society shape an
individual’s food and physical activity choices.167 These elements include individual factors (e.g.,
age, race, income), environmental settings (e.g., schools, food retail establishments), sectors of
influence (e.g., government, industry, media), and social and cultural norms and values (e.g.,
acceptable ranges of body weight, types of foods and beverages consumed).168 Research has
shown that implementing changes at different levels of the social-ecological model is an effective
way to improve eating and physical activity behaviors.
In this context, the 2010 DGA included a new “A Call to Action,” with three guiding principles
accompanied by actionable strategies. One guiding principle—facilitating individual behavior
change by modification to the environmental setting—includes the actionable strategy of
initiating partnerships with the food industry to promote the development and availability of
nutritious and affordable foods.169 The 2015-2020 DGA also discussed the social-ecological
model and the importance of “broad, multisectoral coordination and collaboration” to align
dietary practices with the DGA at the population level, although it did not explicitly mention
working with the food industry.170 The 2015 DGAC’s report, however, included various
recommendations for changing the food environment, for example, by encouraging the food
industry to improve the nutritional profile of certain foods so that they better align with DGA
163 D. Mozaffarian, S. Angell, T. Lang, et al., “Role of Government Policy in Nutrition—Barriers to and Opportunities
for Healthier Eating,” BMJ, June 2018, vol. 361.
164 Ibid.
165 M. McCullough, S. Chantaprasopsuk, F. Islami, et al., “Association of Socioeconomic and Geographic Factors With
Diet Quality in US Adults,” JAMA Network Open, June 2022, vol. 5, no. 6.
166 The 2010 DGAC examined the association between the food environment and body weight, concluding that there is
moderate evidence that the food environment is associated with dietary intake. See https://nesr.usda.gov/whatrelationship-between-environment-body-weight-and-fruitvegetable-consumption#plain-summary.
167 USDA and HHS, Dietary Guidelines for Americans 2010, pp. 55-59, and HHS and USDA, 2015-2020 Dietary
Guidelines for Americans, pp. 64-72.
168 Ibid.
169 USDA and HHS, Dietary Guidelines for Americans 2010, pp. 57-59.
170 HHS and USDA, 2015-2020 Dietary Guidelines for Americans, p. 64.
Congressional Research Service
29
The Dietary Guidelines for Americans: Overview and Considerations for Congress
recommendations.171 The 2020 DGAC did not examine questions related to the food environment
or the overall food system, although the committee did encourage HHS and USDA to examine
these topics to support improved dietary intake.172 The 2020-2025 DGA does not mention the
social-ecological model but does discuss the role of food manufacturers and retail establishments
in supporting Americans achieving a healthy dietary pattern, including through food
reformulation and menu modification.173
In recognition of the food industry’s influence on the food environment, recent federal efforts to
improve the U.S. diet have called for its input and participation. For example, during the White
House Conference on Hunger, Nutrition, and Health held on September 28, 2022, and in the
Biden-Harris Administration National Strategy on Hunger, Nutrition, and Health, the
Administration announced new goals for ending hunger and reducing diet-related disease by
2030.174 Among other things, the National Strategy called on the food industry to increase the
availability of and access to foods that align with the DGA (e.g., low in added sugars and
sodium), particularly for the K-12 schools market.175
Trust in Nutrition Science
Poor adherence to the DGA may also be due, in part, to public distrust of nutrition science.
Observers have noted that the field of nutrition maybe be particularly susceptible to public
distrust for many reasons, including because of the large role the food industry plays in funding,
conducting, and disseminating nutrition research, as well as the perception that dietary
recommendations are frequently changing.176
According to a 2019 Pew Research Center study, 51% of Americans have a positive view of
nutrition research scientists and 11% have a negative view, with the remainder (38%) having
neither positive nor negative views.177 Americans have a more positive view of dietitians (i.e.,
health practitioners) than research scientists (60% versus 51%) but are generally skeptical of
whether research scientists and dietitians are transparent about potential conflicts of interest.
Specifically, Pew found that 12% of Americans believe nutrition researchers are transparent about
potential conflicts of interest, and 37% of Americans believe that dietitians are transparent about
potential conflicts of interest. As discussed in the section “Controversies in the DGA,” conflicts
of interest among DGAC members have been identified, which may affect the public’s trust in the
guidelines.
171 Scientific Report of the 2015 Dietary Guidelines Advisory Committee, Part B. Chapter 2: 2015 DGAC Themes and
Recommendations: Integrating the Evidence, p. 27.
172 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part A. Executive Summary, p. 13.
173 USDA and HHS, Dietary Guidelines for Americans, 2020-2025, p. 50.
174 Biden Harris plan, p. 28, https://www.whitehouse.gov/wp-content/uploads/2022/09/White-House-National-Strategyon-Hunger-Nutrition-and-Health-FINAL.pdf.
175 The White House, “Fact Sheet: The Biden-Harris Administration Announces More Than $8 billion in New
Commitments as Part of Call to Action for White House Conference on Hunger, Nutrition, and Health,” September 28,
2022.
176 C. Garza, P. Stover, Sarah Ohlhorst, et al., “Best Practices in Nutrition Science to Earn and Keep the Public’s
Trust,” American Journal of Clinical Nutrition, 2019, vol. 109, pp. 225-243. NASEM, Evaluating the Process to
Develop the Dietary Guidelines for Americans, 2020-2025: Final Report, p. 27.
177 Pew Research Center, “Trust and Mistrust in Americans’ Views of Scientific Experts,” August 2, 2019, Chapter 5.
Americans trust dietitians more than nutrition researchers but are skeptical of both groups’ transparency, accountability,
pp. 37-47.
Congressional Research Service
30
The Dietary Guidelines for Americans: Overview and Considerations for Congress
The perception that dietary recommendations are frequently changing may also affect public trust
in nutrition science. Although many recommendations have stayed consistent over time—for
example, those encouraging intake of vegetables and fruits and limiting intake of sodium—some
have changed over time (as discussed in the section “Changes in Scientific Evidence”). In
addition, new findings have been reported with respect to health outcomes associated with
consumption of certain foods and beverages, such as coffee, added sugars, and alcohol.178
Experts note that modern science is “inherently tentative, continuous, and iterative in nature.”179
Nutrition is also a relatively young science,180 and recommendations may evolve as new data are
generated. In addition, nutrition research is challenging to conduct, because people’s eating
patterns are complex, and because foods and nutrients are not eaten in isolation. Most nutrition
studies are observational, limiting conclusions about causality. Moreover, confounding variables
such as sleep, exercise, and stress, among others, may affect the relationship between diet and
health.181
The perception that dietary recommendations are frequently changing might be further driven by
the increasingly rapid dissemination of information through social media, making it difficult for
the public to distinguish science from opinion or inadequately substantiated conclusions.182 The
process by which nutrition recommendations are made might also influence public trust in the
science. For example, observers have noted that discrepancies between the recommendations in
the DGAC reports and the final DGA policy document might create confusion and sow public
distrust in the nutrition recommendations.183
Some experts have recommended steps to address concerns about the authoritativeness of dietary
recommendations and to improve trust in nutrition guidance. For example, responding to a
congressional mandate, NASEM published two reports in 2017 with recommendations to
improve the process to develop the DGA. (These recommendations are discussed throughout this
report and summarized in Appendix A.) In its second 2017 report, NASEM identified five values
to improve the integrity of the process “to develop credible and trustworthy guidelines”: (1)
enhance transparency, (2) promote diversity of expertise and experience, (3) support a
deliberative process, (4) manage biases and conflicts of interest, and (5) adopt state-of-the-art
processes and methods.184
Congress and the DGA
As discussed throughout this report, Congress has played an active role in establishing
requirements governing the DGA. This role includes establishing broad requirements applicable
to each edition of the DGA, as well as policy riders affecting specific editions of the DGA. With
178 HHS and USDA, 2015-2020 Dietary Guidelines for Americans, pp. 33-34. See also T. R. Goldman, “Health Policy
Brief: Final 2015-20 Dietary Guidelines for Americans,” Health Affairs, March 31, 2016.
179 C. Garza, P. Stover, Sarah Ohlhorst, et al., “Best Practices in Nutrition Science to Earn and Keep the Public’s
Trust,” American Journal of Clinical Nutrition, 2019, vol. 109, pp. 225-243.
180 T. R. Goldman, “Health Policy Brief: Final 2015-20 Dietary Guidelines for Americans,” Health Affairs, March 31,
2016.
181 Ibid.
182 C. Garza, P. Stover, Sarah Ohlhorst, et al., “Best Practices in Nutrition Science to Earn and Keep the Public’s
Trust,” American Journal of Clinical Nutrition, 2019, vol. 109, pp. 225-243.
183 NASEM, Evaluating the Process to Develop the Dietary Guidelines for Americans, 2020-2025: Final Report, p. 26.
184 NASEM, Redesigning the Process for Establishing the Dietary Guidelines for Americans, 2017, p. 6.
Congressional Research Service
31
The Dietary Guidelines for Americans: Overview and Considerations for Congress
the passage of the National Nutrition Monitoring and Related Research Act of 1990, Congress
established a statutory mandate for HHS and USDA to review and issue the DGA every five years
“based on the preponderance of evidence.” In 2014, Congress required that, beginning in 2020,
the DGA include recommendations for infants, toddlers, and pregnant women.
During the 2015-2020 DGA development process, in response to stakeholder concerns
surrounding the scope of the 2015 DGAC’s report and the process used to develop the 2015-2020
DGA, Congress held hearings and included several DGA-related policy riders in the FY2016
Omnibus Appropriations Act (P.L. 114-113), which limited the scope of the 2015-2020 DGA to
information or guidelines that are “nutritional and dietary” and are “based on significant scientific
agreement.”185 The law also provided $1 million for the USDA Secretary to engage NASEM to
conduct a comprehensive study of the process used to establish the 2015 DGAC and the
subsequent development of the 2015-2020 DGA, as specified.186 Some observers noted that
Congress’s role in the 2015-2020 DGA was unusual, particularly the appropriations riders.187
In subsequent years, Congress included related policy riders in appropriations acts. For example,
the Consolidated Appropriations Act, 2019 (P.L. 116-6), required the USDA Secretary to submit a
report to Congress summarizing the process used to develop the 2020-2025 DGA and an
explanation of the decisions to incorporate or exclude recommendations from NASEM’s 2017
report Redesigning the Process for Establishing the Dietary Guidelines for Americans.188 The
Consolidated Appropriations Act, 2021 (P.L. 116-260), required that NASEM submit a report to
Congress, HHS, and USDA providing a comparative analysis of the processes and methodologies
used to develop the 2020-2025 DGA compared with recommendations in NASEM’s 2017 report
Redesigning the Process for Establishing the Dietary Guidelines for Americans.189
Congress also plays an indirect role in the development of the DGA, for example, by
appropriating funds to HHS and USDA for DGA development and by confirming the
appointments of the Secretaries of HHS and USDA, who are responsible for signing off on the
final policy document.
Going forward, Congress might consider legislation that would further modify the DGA
development process. For example, Congress might direct HHS and USDA to adopt certain
NASEM recommendations in the development of subsequent editions of the DGA, particularly
those recommendations not previously adopted by the departments (see Appendix A). Congress
also might limit or broaden the scope of the DGA to expressly include issues such as
sustainability. Congress may also require further studies of the DGA development process to
inform additional changes to the process and increase public trust in the policy document.
185 P.L. 114-113, §734.
186 P.L. 114-113, §735.
187 T. R. Goldman, “Health Policy Brief: Final 2015-20 Dietary Guidelines for Americans,” Health Affairs, March 31,
2016.
188 P.L. 116-6, §766.
189 P.L. 116-260, §796.
Congressional Research Service
32
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Appendix A. Summary of NASEM Reports
To fulfill a statutory directive in the 2016 Consolidated Appropriations Act, NASEM appointed
an ad hoc committee to evaluate the 2015-2020 DGA development process and make
recommendations for changes to the process, which resulted in two reports that were published in
2017.190 Subsequently in 2021, Congress directed NASEM to evaluate HHS and USDA’s
implementation of the 2017 recommendations in the 2020-2025 DGA. Pursuant to this directive,
NASEM convened a new ad hoc committee and, in 2022, published two reports evaluating HHS
and USDA’s adoption of its recommendations in the development of the 2020-2025 DGA.191
NASEM’s 2017 recommendation and evaluation of the departments’ implementation of the
recommendations are summarized below. In its 2022 reports, NASEM did not evaluate the
departments’ implementation of its recommendations from the report, Optimizing the Process for
Establishing the Dietary Guidelines for Americans: The Selection Process.
2017 NASEM Recommendations and HHS and USDA Implementation for the
2020-2025 DGA
From Redesigning the Process for Establishing the Dietary Guidelines for Americans, 2017, pp. 9-15:
Recommendation 1. The Secretaries of USDA and HHS should redesign the DGA process to prioritize topics
to be reviewed in each DGA cycle, and redistribute the current functions of the DGAC to three separate groups:
a. Dietary Guidelines Planning and Continuity Group to monitor and curate evidence generation, to identify
and prioritize topics for inclusion in the DGA, and to provide strategic planning support across DGA cycles;
b. Technical expert panels to provide content and methodological consultation during evaluation of the
evidence; and
c. Dietary Guidelines Scientific Advisory Committee to interpret the scientific evidence and draw conclusions.
HHS/USDA Implementation: NASEM found that that the major elements of this recommendation, specifically to
redistribute the functions of the DGAC to three separate groups, were not implemented, although HHS and
USDA did make changes to the process during the development of the 2020-2025 DGA that partially met the
intent of redistributing some of the functions.
Recommendation 2. The Secretaries of USDA and HHS should provide the public with a clear explanation
when the DGA omit or accept only parts of conclusions from the scientific report.
HHS/USDA Implementation: NASEM found that this recommendation was substantially implemented in the
development of the 2020-2025 DGA.
Recommendation 3. The USDA Secretary should clearly separate the roles of NESR staff and the DGSAC so
that:
a. The NESR staff plan and conduct systematic reviews with input from technical expert panels, perform the
risk of-bias assessment of individual studies, and assist the DGSAC as needed;
b. The NESR systematic reviews are externally peer reviewed before being made available for use by the
DGSAC; and
c. The DGSAC synthesizes and interprets the results of systematic reviews and draws conclusions about the
entire body of evidence.
HHS/USDA Implementation: NASEM found that this recommendation was partially implemented. For example,
while the DGSAC was not created, the DGAC synthesized and interpreted systematic review results and drew
190 National Academies of Sciences, Engineering, and Medicine (NASEM), Optimizing the Process for Establishing the
Dietary Guidelines for Americans: The Selection Process, 2017, and Redesigning the Process for Establishing the
Dietary Guidelines for Americans, 2017 (Washington, DC: National Academies Press).
191 NASEM, Evaluating the Process to Develop the Dietary Guidelines for Americans, 2020-2025: A Midcourse
Report, 2022, and Evaluating the Process to Develop the Dietary Guidelines for Americans, 2020-2025: Final Report,
2022 (Washington, DC: National Academies Press).
Congressional Research Service
33
The Dietary Guidelines for Americans: Overview and Considerations for Congress
conclusions independent of NESR. In addition, the Departments did solicit peer review of systematic reviews for
the first time, but the reviews were not external to the federal government.
Recommendation 4. The USDA Secretary should ensure all NESR systematic reviews align with best practices
by:
a. Enabling ongoing training of the NESR staff;
b. Enabling engagement with, and learning from, external groups on the forefront of systematic review
methods;
c. Inviting external systematic review experts to periodically evaluate the NESR’s methods; and
d. Investing in technological infrastructure.
HHS/USDA Implementation: NASEM found that this recommendation was substantially implemented.
Recommendation 5. The Secretaries of HHS and USDA should enhance food pattern modeling to better
reflect the complex interactions involved, the variability in intakes, and the range of possible healthful diets.
HHS/USDA Implementation: NASEM concluded that some refinements were made to the food pattern
modeling used to develop the 2020-2025 DGA, but the analytic methods did not change.
Recommendation 6. The Secretaries of HHS and USDA should standardize the methods and criteria for
establishing nutrients of concern.
HHS/USDA Implementation: NASEM found that this recommendation was almost fully implemented.
Recommendation 7. The Secretaries of HHS and USDA should commission research and evaluate strategies to
develop and implement systems approaches into the DGA. The selected strategies should then begin to be used
to integrate systems mapping and modeling into the DGA process.
HHS and USDA Implementation: NASEM found that none of this recommendation was implemented as
proposed.
From Optimizing the Process for Establishing the Dietary Guidelines for Americans: The Selection Process,
2017, pp. 7-11:
Recommendation 1. The Secretaries of USDA and HHS should employ an external third party to review and
narrow the candidate pool to a list of primary and alternate nominees. Criteria against which nominees are
screened should be developed by USDA and HHS for use by the third party.
Recommendation 2. The Secretaries of USDA and HHS should make a list of provisional appointees open for
public comment—including short biographies and any known conflicts—for a reasonable period of time prior to
appointment.
Recommendation 3. The Secretaries of USDA and HHS should disclose how provisional nominees’ biases and
conflicts of interest are identified and managed by
a. Creating and publicly posting a policy and form to explicitly disclose financial and nonfinancial biases and
conflicts;
b. Developing a management plan for addressing biases and conflicts for the panel as a whole and individuals, as
needed;
c. Certifying that a federal ethics officer independently reviewed and judged the advisory committee’s biases
and conflicts of interest; and
d. Documenting how conflicts of interest were managed in the DGAC report.
Recommendation 4. The Secretaries of USDA and HHS should adopt a system for continuous process
improvement to enhance outcomes and performance of the DGAC selection process.
Congressional Research Service
34
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Appendix B. The DGAC’s Approaches to Reviewing
the Evidence
Today, the DGACs primarily use three approaches to review the scientific evidence: Nutrition
Evidence Systematic Review (NESR) systematic reviews, data analyses, and food pattern
modeling. These approaches are described in more detail below.
Congressional Research Service
35
The Dietary Guidelines for Americans: Overview and Considerations for Congress
NESR
In 2008, USDA’s CNPP established the NESR to conduct food- and nutrition-related systematic reviews. This
systematic review methodology was developed in consultation with the Agency for Healthcare Research and
Quality (AHRQ), and the Academy of Nutrition and Dietetics, and informed by the U.S. Cochrane Collaboration.
NESR was created to ensure compliance with Section 515 of the Consolidated Appropriations Act of 2001 (P.L.
106-554, the Data Quality Act), which directed the Office of Management of Budget (OMB) to issue governmentwide guidelines that “provide policy and procedural guidance to Federal agencies for ensuring and maximizing the
quality, objectivity, utility, and integrity of information (including statistical information) disseminated by Federal
agencies.” NESR’s work helps federal agencies and programs comply with these requirements.192
NESR uses a six-step process to conduct specialized systematic reviews and is designed to promote transparency,
minimize bias, and ensure the availability of systematic reviews that are relevant, timely, and high quality. These
steps are as follows:
1. Develop high-priority questions. Federal stakeholders develop systematic review questions that
address food and nutrition topics, are important to public health, and that can inform federal guidance and
programs. NESR analysts then work with scientific experts to develop an analytic framework for each
systematic review question, which includes defining key terms, identifying the population of interest and
outcomes, and identifying confounders, among other things.
2. Search for and screen studies. The next step involves establishing inclusion and exclusion criteria for
studies, including study design, publication date, and participant characteristics, among others. NESR librarians
create a search strategy based on the analytic framework and inclusion/exclusion criteria, and then NESR
analysts screen potentially relevant studies, documenting which studies were excluded and why.
3. Extract data and assess the risk of bias. NESR analysts extract certain data and information (e.g.,
study design, participant characteristics, results, funding source) to help answer each systematic review
question. NESR analysts also use a risk of bias tool to assess how a study was designed and conducted, which
can affect the accuracy of its results.
4. Synthesize the evidence. NESR analysts then work with scientific experts to synthesize the evidence
from the included studies, which involves examining similarities and differences between the studies and their
results, identifying gaps and limitations, and determining whether other factors may affect the relationships
being examined.
5. Answer the question and grade the evidence. The scientific experts, with help from NESR analysts,
then use the evidence synthesis to develop conclusion statements to answer the systematic review questions.
They also grade the strength of the evidence (i.e., strong, moderate, limited, and grade not assignable).
6. Recommend future research. NESR analysts and external experts (e.g., DGAC committee members)
recommend future research based on the gaps and limitations that were identified.193
NESR makes information about its systematic reviews publicly available, posting on its website a plain language
summary of each review, a technical abstract, and the full systematic review.194
Data Analysis
The DGACs have relied upon several federal sources of data, including the National Health and Nutrition
Examination Survey (NHANES) and the National Health Interview Survey (NHIS).195 The dietary component of
NHANES, What We Eat in America (WWEIA), for example, is used to understand the eating habits of the U.S.
population using data obtained from 24-hour dietary recalls. NHANES physical exams and laboratory data are
used to assess physical and biochemical indicators of health. The NHIS provides data on the U.S. population for
analyzing health trends and tracking progress toward achieving national health objectives. NHANES and the NHIS
are managed by the National Center for Health Statistics (NCHS) at the Centers for Disease Control and
Prevention (CDC).
Food Pattern Modeling
192 USDA, Nutrition Evidence Systematic Review Methodology, https://nesr.usda.gov/nutrition-evidence-systematic-
review-methodology.
193 Ibid.
194 Ibid.
195 Scientific Report of the 2020 Dietary Guidelines Advisory Committee, Part C. Methodology, p. 13.
Congressional Research Service
R47488 · VERSION 1 · NEW
36
The Dietary Guidelines for Americans: Overview and Considerations for Congress
Food pattern modeling are analyses that show how changes to food-based dietary recommendations might affect
the U.S. population’s ability to meet nutrient needs.196 Different elements of the food pattern can be modified, for
example, food group amounts and the inclusion or exclusion of certain foods. As an example, the 2020 DGAC
used food pattern modeling to examine the relationship between added sugars consumption and achieving nutrient
and food group recommendations.
Author Information
Matthew B. Barry, Coordinator
Section Research Manager
Acknowledgments
Agata Bodie, former CRS Analyst in Health Policy, researched, prepared, and wrote this report.
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan
shared staff to congressional committees and Members of Congress. It operates solely at the behest of and
under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other
than public understanding of information that has been provided by CRS to Members of Congress in
connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not
subject to copyright protection in the United States. Any CRS Report may be reproduced and distributed in
its entirety without permission from CRS. However, as a CRS Report may include copyrighted images or
material from a third party, you may need to obtain the permission of the copyright holder if you wish to
copy or otherwise use copyrighted material.
196 Ibid., pp. 16-17.
Congressional Research Service
R47488 · VERSION 1 · NEW
37
This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.