Purpose: Discuss the findings from select systematic reviews, focused on women who are pregnant or lactating, conducted by the 2020 Dietary Guidelines Advisory Committee with support from the USDA’s Nutrition Evidence Systematic Review (NESR) team. Specifically, the presentation will highlight two systematic review questions regarding the relationships between dietary patterns and 2 outcomes: gestational weight gain (GWG) and postpartum weight loss (PPWL).

Methods: The Committee developed protocols that described how they would use NESR’s systematic review methodology to examine the systematic review questions. NESR conducted a literature search and dual-screened the results using pre-defined inclusion and exclusion criteria to identify articles published between Jan 2000 and Nov 2019. NESR extracted data and assessed risk of bias of included studies. The Committee synthesized the evidence, developed conclusion statements, and graded the strength of the evidence underlying the conclusion statements.

Results: Twenty-six articles were included in the GWG review and 1 article in the PPWL review. The GWG review included 5 RCTs and 21 prospective cohort studies. Two RCTs showed that a “beneficial” DP was associated with lower GWG. Thirteen of the 20 observational studies showed an association between DP and GWG. Although the DPs examined were characterized by different combinations of foods and beverages, the patterns consistently associated with lower GWG were higher in vegetables, fruits, nuts, legumes, and fish and lower in added sugars and red and processed meats. The PPWL review included only one RCT, which was limited by high attrition, issues with implementing the intervention, and lack of blinding.

Conclusions: Limited evidence suggests that certain DPs during pregnancy are associated with a lower risk of excessive GWG. These patterns are higher in vegetables, fruits, nuts, legumes, and fish, and lower in added sugar, and red and processed meat (Grade: Limited). Insufficient evidence is available to determine the relationship between DPs during lactation and PPWL (Grade: Grade Not Assignable).

Purpose: Overview findings from systematic reviews conducted by the 2020 Dietary Guidelines Advisory Committee with support from USDA’s Nutrition Evidence Systematic Review (NESR) team that examined dietary patterns at each stage of life and health outcomes across the lifespan, with specific reviews highlighted in-depth.

Methods: The Committee developed protocols that described how they would use NESR’s systematic review methodology to examine the evidence. NESR librarians conducted peer-reviewed literature searching in at least 3 databases. NESR analysts, guided by analytic frameworks and pre-defined inclusion and exclusion criteria for each systematic review question, dual-screened literature search results to identify relevant articles. NESR extracted data and assessed risk of bias of included studies. Committee members reviewed and synthesized the evidence, formed conclusion statements, and graded the strength of the evidence supporting those conclusions.

Results: Components of a “healthy dietary pattern” commonly associated with favorable health outcomes included vegetables, fruits, legumes, whole grains, low- or non-fat dairy, seafood, nuts, and unsaturated vegetable oils, and low consumption of red and processed meats, sugar-sweetened foods and drinks, and refined grains. The evidence in adults was graded as Moderate or Strong for the following outcomes: all-cause mortality, bone health, breast cancer, colon cancer, cardiovascular disease, overweight and obesity, and type 2 diabetes; and graded as Limited for neurocognitive health, lung cancer, and prostate cancer outcomes. Insufficient evidence was available for the outcome of sarcopenia. Relative to adults, insufficient evidence was available that examined dietary patterns consumed by children and adolescents and most of these outcomes. However, limited evidence was available for children and adolescents that suggests a similar healthy dietary pattern is associated with better health outcomes for CVD risk factors and adiposity.

Conclusions: A healthy dietary pattern consisting of vegetables, fruits, and whole grains is associated with better health outcomes across the lifespan, although the strength of evidence varies. More evidence is needed to determine the relationship between dietary patterns and sarcopenia in adults, as well as dietary patterns consumed during infancy and toddlerhood, childhood, and adolescence.  

Purpose: Overview how the work of the 2020 Dietary Guidelines Advisory Committee is translated into the Dietary Guidelines for Americans, which in turn informs Federal programs, such as MyPlate’s Start Simple tools and resources.

Methods: The Committee used three approaches to examine the evidence. Data Analysis from national datasets helps us understand the current health status and dietary intakes of Americans. It is what makes the Dietary Guidelines “for Americans.” Food Pattern Modeling allows the Committee to develop healthy dietary patterns that promote health and meet nutrients needs. Systematic Reviews of the evidence allows the Committee to synthesize all of the relevant peer-reviewed studies on a diet and health topic. Each of these approaches has its own rigorous, protocol-driven methodology, and plays a unique, complementary role in examining the science. These approaches inform the Committee’s scientific report. USDA and HHS use the scientific report as the scientific basis for revisions to the Dietary Guidelines for Americans, along with a review of public and agency comments. USDA and HHS then release the next edition of the Dietary Guidelines that provides central guidance to inform Federal nutrition programs, including MyPlate tools and resources that provide tips and strategies to help Americans improve their diet.

Results: The Dietary Guidelines for Americans demonstrates that American diets are falling short from meeting key recommendations. Implementation strategies to help Americans improve their diets are needed. Personalized advice and strategies can better meet people where they are to start making behavior changes. MyPlate.gov and the Start Simple with MyPlate app were both designed to help Americans customize and personalize their healthy eating goals to improve their dietary patterns to better align with the Dietary Guidelines.

Conclusions: Personalized advice provided through interactive tools such as MyPlate.gov and the Start Simple with MyPlate app can better meet people where they are to help them improve their dietary patterns to align with the Dietary Guidelines, which science demonstrates can promote health and reduce disease risk.