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Introduction

The first edition of the Dietary Guidelines for Americans (DGA) was released in 1980, when the U.S. Department of Agriculture (USDA) and the U.S. Department of Health and Human Services (HHS) collaboratively issued Nutrition and Your Health: Dietary Guidelines for Americans (USDA/HHS, n.d.a). USDA and HHS voluntarily issued subsequent editions of the DGA in 1985 and 1990, and passage of the National Nutrition Monitoring and Related Research Act in 1990 mandated that the two Departments jointly publish a report at least every five years that “shall contain nutritional and dietary information and guidelines for the general public” (USDA/HHS, n.d.b).¹ The ninth and most recent edition of this report is the Dietary Guidelines for Americans, 2020–2025 (2020–2025 DGA) (USDA/HHS, 2020).

The DGA provide evidence-based advice about what to eat and drink to build a diet that can promote healthy growth and development, help prevent diet-related chronic disease, and meet nutrient needs. As noted in the 2020–2025 DGA, the guidelines are “designed for policymakers and nutrition and health professionals to help all individuals and their families consume a healthy, nutritionally adequate diet” (USDA/HHS, 2020), and thus provide the basis for federal food and nutrition policies and programs.

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¹ National Nutrition Monitoring and Related Research Act of 1990, Public Law 101-445, 101st Cong. (October 22, 1990). https://www.govinfo.gov/content/pkg/STATUTE-104/pdf/STATUTE-104-Pg1034.pdf

Guideline development is a complex process, in part because the underlying science is continuously evolving. Each edition of the DGA is modified to reflect the preponderance of scientific evidence at the time of its preparation. Beginning with the 1985 (second) edition, USDA and HHS have convened a federal advisory committee—the Dietary Guidelines Advisory Committee (DGAC)—composed of external (i.e., outside of the federal government) experts to evaluate relevant scientific data and inform the development of the DGA. Each DGAC is convened in accordance with the Federal Advisory Committee Act and its members serve for up to a 2-year period (GSA, 2019). Recent DGACs have examined relevant scientific evidence through systematic reviews, data analysis, and food pattern modeling. The DGAC then presents its conclusions in a scientific report that, along with public comments and input from other federal agencies, informs USDA and HHS as they develop the next edition of the DGA.

BACKGROUND FOR THE STUDY

The release of the Scientific Report of the 2015 Dietary Guidelines Advisory Committee (2015 DGAC Scientific Report) (DGAC, 2015), in January 2015, elicited more than 29,000 public comments during the 75-day comment period (HHS, 2021), many of which questioned the process used to develop the report and/or the report’s conclusions (HHS, 2015). These comments included questions about how the translation of the 2015 DGAC Scientific Report to the 2015–2020 DGA would occur as well as questions about the transparency and integrity of the overall process used to develop the DGA. Congress was concerned about these comments and questions as well as the low level of adherence to the DGA, which suggested a lack of trust in them (NASEM, 2017a). These concerns prompted Congress to direct USDA to engage the National Academies of Sciences, Engineering, and Medicine (the National Academies) to conduct a comprehensive study of the process used to establish the 2015–2020 DGA.²

2017 Recommendations for Redesigning the Process for Establishing the Dietary Guidelines for Americans

To fulfill the Congressional mandate, the National Academies convened the Committee on Redesigning the Process for Establishing the Dietary Guidelines for Americans (the 2017 report committee), which in 2017 produced two reports that provided recommendations for updating the process to develop the DGA. The first report provided recom-

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² Consolidated Appropriations Act, 2016, Public Law 114-113, 114th Cong. (December 18, 2015), 129 Stat. 2280–2281. https://www.congress.gov/114/plaws/publ113/PLAW-114publ113.pdf

mendations for selecting members of the DGAC, including managing biases and conflicts of interest of DGAC members (NASEM, 2017a), and the second provided recommendations for changes to the process used to develop the DGA (Box 1-1) (NASEM, 2017b). These recommendations reflect the 2017 report committee’s stated values for improving the integrity of the DGA process: enhance transparency, manage overall bias and conflict of interest, promote diversity of expertise and experience, support a deliberative process, and adopt state-of-the-art processes and methods (NASEM, 2017b). In the view of the 2017 report committee, “the adoption and widespread translation of the DGA require that they be… viewed as valid, evidence-based, and free of bias and conflicts of interest to the extent possible” (NASEM, 2017b). The committee’s seven recommendations for redesigning the process to develop the DGA were directed toward achieving this goal.

USDA and HHS’s commitment to undertake a transparent, science-driven process for developing the DGA led them to take numerous steps to address the recommendations from the 2017 National Academies reports as they developed the subsequent edition of the DGA (i.e., the 2020–2025 DGA, released in December 2020) (DGA, 2021).

THE COMMITTEE’S TASK

In March 2021, Congress included language in its Consolidated Appropriations Act (Section 796) citing interest in the process used to develop the 2020–2025 DGA,³ particularly related to the extent to which USDA considered in its decision-making the recommendations in the National Academies’ 2017 report, Redesigning the Process for Establishing the Dietary Guidelines for Americans (NASEM, 2017b). The Consolidated Appropriations Act provided funding for USDA to sponsor the present study and outlined the study tasks (Box 1-2). USDA and HHS provided specific questions associated with each of the three tasks (Box 1-2). The tasks excluded providing recommendations for future cycles of the DGA.

The National Academies established a committee with expertise in nutrition, dietary assessment, food pattern modeling, systematic review standards and methodologies, clinical nutrition research, systems science, epidemiology, program design and evaluation, life cycle nutrition, public health nutrition, statistics/biostatistics, nutrition education, nutrition policy research and development, federal nutrition program planning, health impact analysis, and continuous process improvement methodologies.

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³ Consolidated Appropriations Act, 2021, Public Law 116-260, 117th Cong. (March 2021), 133. https://www.govinfo.gov/content/pkg/CPRT-117HPRT43749/html/CPRT-117HPRT43749.htm.

Midcourse Report

The committee issued a midcourse report, Evaluating the Process to Develop the Dietary Guidelines for Americans, 2020–2025: A Midcourse Report (NASEM, 2022) in May 2022. The midcourse report described the committee’s research methodology and deliberations, as well as its preliminary findings and conclusions for Task 1 and Task 2 (Box 1-2).

Final Report

This report provides the committee’s final conclusions for each of the three tasks in its Statement of Task (Box 1-2). The findings and conclusions have been informed by the committee’s integration of additional evidence gathered since the release of the midcourse report—including evidence gathered during open public sessions with subject matter experts as well as employees of USDA and HHS to gain information and insights—and its deliberations during closed sessions and conference calls.

ORGANIZATION OF THE FINAL REPORT

This final report is organized into five chapters. Chapter 1 describes the study background and Statement of Task. Chapter 2 provides the context for Task 3, including an overview of key elements of the process by which the DGA are developed and discusses the inherent challenges in this process. Chapter 3 reviews the committee’s methods for approaching Task 3. Chapter 4 presents the committee’s findings and conclusions for Task 3, and Chapter 5 contains the committee’s overall conclusions and perspectives. In addition to the chapters, the committee biographies are found within Appendix A. The committee highlights elements in the DGA process in Appendix B and lists data sources used by the 2020 DGAC in Appendix C. Finally, the committee presents evidence provided in open session and written responses from the Departments that were provided in response to questions from the committee in Appendix D.

REFERENCES

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