ASN helps members navigate the DGA and understand the science underlying its recommendations.

Published every five years, the Dietary Guidelines for Americans (DGA) sets forth what Americans should eat and drink to support good health and prevent chronic disease.  Since 1985, each DGA edition has been informed by the Dietary Guidelines Advisory Committee’s report: the latest, the Scientific Report of the 2020 Dietary Guidelines Advisory Committee, was published July 2020.  This report reviewed the current state of nutrition science, offering evidence that supported the recommendations of the 2020-2025 edition of the DGA, published December 2020.

ASN is proud to note that 16 of the 20 appointees to 2020 Dietary Guidelines Advisory Committee (DGAC) were ASN members, including three past ASN Presidents: Richard Mattes, Sharon Donovan, and Teresa Davis.

To learn more about the 2020-2025 DGA, tune into ASN’s three-part webinar series, originally broadcast in early 2021.  The series helps you navigate the DGA and gain fresh insight into the science used to inform the recommendations.

The evidence supporting the 2020-2025 DGA is extensively documented in the DGAC’s Scientific Report.  In addition, members of the DGAC and federal staff have published additional work related to development of the 2020-2025 DGA in peer-reviewed publications, including ASN Journals.  These articles provide additional insight into the science and considerations underlying both the scope and the recommendations of the DGA.  Below are select highlights:

Breastfeeding and Risk of Overweight in Childhood and Beyond: A Systematic Review with Emphasis on Sibling-Pair and Intervention Studies, The American Journal of Clinical Nutrition, November 2021

Breastfeeding is associated with a lower risk of subsequent overweight or obesity, but it is uncertain whether there is a causal relationship.  In response, the 2020 DGAC, together with the Nutrition Evidence Systematic Review team, conducted a systematic review of articles relevant to healthy full-term infants.  ASN member and 2020 DGAC member Kathryn G. Dewey et al. located 42 relevant studies, including six cohorts with sibling-pair analyses.  The authors did find “moderate evidence” suggesting that “ever, compared with never, consuming human milk is associated with a lower risk of overweight and obesity at ages two years and older, particularly if the duration of human milk consumption is more than six months.”  The authors caution that residual confounding cannot be ruled out.  In particular, few studies accounted for complementary feeding practices and childhood diet, both likely to influence the risk of overweight and obesity.  In summary, “evidence was insufficient to determine the relation between the duration of any human milk consumption among infants fed human milk and overweight and/or obesity at age two years and older.”

Perspective: Impact of the National Academy of Sciences, Engineering, and Medicine Report on the Process for the 2020 Dietary Guidelines Advisory Committee, Advances in Nutrition, July 2021

The National Academy of Sciences, Engineering, and Medicine (NASEM) recommended steps to redesign the process of developing the 2020-2025 DGA based on five guiding principles: enhance transparency; promote diversity of expertise and experience; support a deliberative process; manage biases and conflicts of interest; and adopt state-of-the-art processes and methods.  This Perspective explains how the NASEM recommendations guided the DGAC in developing the Scientific Report.  The authors, ASN member and 2020 DGAC Chair Barbara O. Schneeman et al., noted that, in an effort to follow NASEM’s recommendations, “establishing topics and questions in advance of appointing and charging the DGAC was a new step.”  Moreover, based on NASEM’s recommendations, a public meeting to discuss the final Scientific Report before its submission to the Secretaries of the USDA and HHS was also added.  According to the authors, “implementing these new steps enabled the development of the DGA “to focus on recommendations and advice that is of greatest relevance to nutrition and public health for the American people.”

A Proposed Framework for Identifying Nutrients and Food Components of Public Health Relevance in the Dietary Guidelines for Americans, The Journal of Nutrition, May 2021

Identifying nutrients of public health concern has been a key task of the DGAC.  In response, ASN member and 2020 DGAC member Regan L. Bailey et al. proposed a framework for identifying nutrients or food components of public health relevance to inform the 2020-2025 DGA.  The framework focuses on “defining terminology; establishing quantitative thresholds to identify nutrients or food components; and examining national data.”  Moreover, the framework leverages data from three key data sources: “dietary intakes, biological endpoints, and clinical health consequences such as prevalence of health conditions, directly or indirectly through validated surrogate markers.”  In developing this systematic framework, the authors noted that “several data gaps or scientific issues emerged.” For example, “some dietary reference intake (DRI) values may not reflect the totality of more current evidence.”  Overall, however, the authors believe that “the proposed decision-tree framework was intended to streamline and add transparency to the work of this and future Dietary Guidelines Advisory Committees to identify nutrients or food components that need to be encouraged or discouraged in order to help reduce risk of chronic disease and promote health and energy balance in the population.”

A complete list of peer-reviewed publications authored by the DGAC is available here.  Moving forward, ASN will continue to foster and publish new research to support future editions of the DGA as well as help our membership take full advantage of each new edition.