2025 Dietary Guidelines Advisory Committee Examine the Evidence
The 2025 Dietary Guidelines Advisory Committee (Committee) is using three approaches to review the scientific evidence on nutrition and health: data analysis, food pattern modeling, and systematic reviews. Each approach has its own rigorous, protocol-driven methodology, and plays a unique, complementary role in examining the science.
Data analysis uses statistical methods to analyze national data sets to describe the current health and dietary intakes in the United States. This approach helps the Committee ensure its recommendations are practical, relevant, and achievable.
Data Analysis for the 2025 Dietary Guidelines Advisory Committee
The Committee is using data analysis to describe the following:
- Current patterns of food and beverage consumption
- Current intake of food groups, nutrients, and dietary components
- Nutrients and/or dietary components of public health concern
- Prevalence of nutrition-related chronic health conditions
Federal staff will analyze data sets and deliver the findings to the Committee to inform results and conclusions in the Scientific Report. The Committee will inform the analytic approaches using a health equity lens to ensure the data describes and considers factors such as socioeconomic position, food security, race/ethnicity, and culture.
Federal Data Sources
A collection of Federal data sources informs the Committee’s work. Each of these data sources is described below.
Description of Data Sources
National Health and Nutrition Examination Survey NHANES
U.S. Department of Health and Human Services (HHS), Centers for Disease Control and Prevention (CDC), National Center for Health Statistics
U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS), Food Surveys Research Group (FSRG)
NHANES is a federal program of studies designed to assess the health and nutritional status of U.S. children and adults residing in the 50 states and District of Columbia. The nationally representative survey includes interviews (e.g., 24-hour dietary recall), questionnaires (e.g., demographics, food security, income), laboratory data (e.g., folate status or other biochemical markers of public health relevance), and physical examinations (e.g., height, weight, blood pressure), that measure dietary intakes and diet-related chronic disease rates in the U.S. population. What We Eat in America, National Health and Nutrition Examination Survey (WWEIA, NHANES) USDA, ARS, FSRG The dietary component of NHANES, called WWEIA, is the only nationally representative survey of total food and beverage consumption that captures intakes across life stages on a population level in the United States. The dietary data are collected using the gold standard for dietary assessment: a multiple pass, 24-hour dietary recall. USDA Food and Nutrient Database for Dietary Studies (FNDDS) USDA, ARS, FSRG FNDDS is a database that provides the energy and nutrient values for foods and beverages reported in WWEIA, NHANES. Data are available on energy and 64 nutrients for ~7,000 foods and beverages. It can be used to examine nutrient intakes from foods and beverages reported by participants in WWEIA, NHANES and assess adherence to Dietary Reference Intakes.
USDA Food Pattern Equivalents Database (FPED)
USDA, ARS, FSRG FPED converts foods and beverages from FNDDS into 37 USDA Food Patterns components. It can be used to examine food group intakes (e.g., Whole Fruit, Total Vegetables, Added Sugars) from foods and beverages reported by participants in WWEIA, NHANES and assess adherence to Dietary Guidelines food group recommendations. WWEIA Food Categories USDA, ARS, FSRG WWEIA Food Categories provide an application to analyze the foods and beverages reported by participants in WWEIA, NHANES. Each food and beverage are placed in one of 167 mutually exclusive food categories, where similar items are grouped together based on their typical use and nutrient content (e.g., Mixed Dishes – Asian, Savory Snacks, Cooked Cereals). National Health Interview Survey (NHIS) HHS, CDC, National Center for Health Statistics NHIS is a survey on health conducted using in-person, confidential household interviews. It provides data on the U.S. civilian noninstitutionalized population residing in the 50 states and District of Columbia for analyzing public health trends, assessing prevalence of health conditions, and tracking progress toward achieving national health objectives. Surveillance, Epidemiology and End Results (SEER)
HHS, NIH, National Cancer Institute, Division of Cancer Control and Population Sciences
The SEER Program is the authoritative source for cancer statistics in the U.S. population.
SEER collects and publishes cancer incidence and survival data from population-based cancer registries. The 22 geographic areas of data collection from the U.S. states and American Indian/Alaskan Native communities are representative of the demographics of the entire U.S. population.
National Vital Statistics System (NVSS)
HHS, CDC, National Center for Health Statistics
NVSS collects and disseminates the most complete data on U.S. births and deaths from vital registration systems across 50 states, 2 cities (District of Columbia and New York City), and 5 territories. National Immunization Surveys (NIS) HHS, CDC, National Center for Immunization and Respiratory Diseases NIS are a group of telephone surveys that provide current, population-based, state and local area estimates of vaccination coverage among children 19-35 months and teens 13-17 years. The surveys collect data through telephone interviews with parents or guardians in all 50 states, the District of Columbia, and some U.S. territories (U.S. Virgin Islands, Puerto Rico, Guam).
Using WWEIA, NHANES Data to Understand Current Intakes
The strengths and challenges of self-report dietary assessment are well-recognized. Self-report dietary data are valuable for providing important information at a population level regarding intakes and sources of foods and beverages, and to describe dietary patterns and assess diet quality. Established statistical approaches accounting for day-to-day variability and energy adjustment are used to help reduce potential bias in describing dietary intakes at a population level.
Impact of COVID-19 on Data Collection
Efforts are being made to ensure that data analysis methodologies capture the most updated and relevant data possible, including data that represent potential changes in dietary intake due to the COVID-19 pandemic.
The Federal data analysis team has created the following plan to describe the data analysis process, strategy, and analyses used to support the Committee in answering prioritized scientific questions. The plan describes how the data analysis will be conducted.
July 18, 2023 Data analysis plan Added
July 18, 2023
The “date posted” column shows when the plan was originally posted to this website and the “status” column shows when the plan was most recently updated.
Federal Data Analysis Team
The Federal data analysis team supports the work of the Committee by analyzing data on specific topics and questions. The interagency team includes expert scientists with advanced degrees in nutrition, statistics, and epidemiology from the following Departments and agencies:
United States Department of Health and Human Services
- Office of Disease Prevention and Health Promotion; Office of the Assistant Secretary for Health
- Center for Food Safety and Applied Nutrition; Food and Drug Administration
- National Cancer Institute; National Institutes of Health
- National Center for Health Statistics; Centers for Disease Control and Prevention
United States Department of Agriculture
- Center for Nutrition Policy and Promotion; Food and Nutrition Service; Food, Nutrition, and Consumer Services
- Agricultural Research Service; Research, Education, and Economics
Food pattern modeling is a methodology used to illustrate how changes to the amounts or types of foods and beverages in a dietary pattern might affect meeting nutrient needs, and is used to develop quantitative dietary patterns that reflect health-promoting patterns identified in systematic reviews and meet energy and nutrient needs. This approach allows the Committee to make recommendations to inform the development of dietary patterns for the U.S. population.
Food Pattern Modeling for the 2025 Dietary Guidelines Advisory Committee
The 2025 Committee is using food pattern modeling to answer the following overarching scientific question:
Considering each life stage, should changes be made to the USDA Dietary Patterns (Healthy U.S.-Style, Healthy Mediterranean-Style, and/or Healthy Vegetarian), and should additional Dietary Patterns be developed/proposed based on:
- Findings from systematic reviews, data analysis, and/or food pattern modeling analyses; and/or
- Population norms (e.g., starchy vegetables are often consumed interchangeably with grains), preferences (e.g., emphasis on one staple grain versus another), or needs (e.g., lactose intolerance) of the diverse communities and cultural foodways within the U.S. population?
Changes to Dietary Patterns may include increases or decreases in amounts of food groups/subgroups and/or recategorization of food groups/subgroups, as well as subsequent changes to calories available for other uses, including for added sugars.
This overarching question was informed by goals for the Committee’s food pattern modeling analyses to use enhanced food pattern modeling methodology to better reflect intake variability and the range of possible healthful diets based on our diverse populations.
The Committee has created the following protocols to describe how it will apply food pattern modeling methodology to answer the prioritized scientific question. The Committee is answering the overarching question by conducting a series of analyses, or hypothetical tests, each reflected in individual protocols on this page. Each protocol is created before the Committee examines any evidence, and is posted below for the public to view and better understand the approach to answering a specific question.
The public is encouraged to submit written comments to the Committee on topics relevant to its work, including on its protocols. Additional food pattern modeling protocols are planned and will be posted on this page after the full Committee has had an opportunity to review and discuss during the next public meeting. To see plans for the next round of protocols, view the Subcommittee 3 food pattern modeling presentation from Meeting 3.
The “date posted” column shows when the plan was originally posted to this website, and the “status” column shows when the plan was most recently updated. When a review has been completed, the protocol will remain posted, and the status will be updated to “Completed.”
Food Pattern Modeling Team
The Federal food pattern modeling team supports the work of the Committee by conducting specific food pattern modeling analyses identified by the Committee. The interagency team includes nutrition scientists and data analysts from USDA and HHS with doctoral (PhD, DrPH, ScD, and MD) or master’s degrees (MS, MPH) in nutrition science, public health, economics, or related fields and expertise in food pattern modeling methodology. Some are registered dietitians (RD) or registered dietitian nutritionists (RDN).
A Nutrition Evidence Systematic Review (NESR) systematic review is a gold-standard evidence synthesis project that answers a nutrition question of public health importance using systematic, transparent, rigorous, and protocol-driven methods to search for, evaluate, synthesize, and grade the strength of the eligible body of evidence. This approach allows the Committee to answer high priority scientific questions by reviewing evidence from all relevant studies that have been published on a particular topic.
Systematic Reviews for the 2025 Dietary Guidelines Advisory Committee
USDA’s NESR team is supporting the 2025 Dietary Guidelines Advisory Committee in conducting original systematic reviews.
The Committee will use NESR’s rigorous and transparent methodology to conduct and/or update systematic reviews. NESR’s systematic review methodology involves:
- developing a systematic review protocol,
- searching for and screening articles,
- extracting data from and assessing the risk of bias of each included article,
- synthesizing the evidence,
- developing the conclusion statement(s),
- grading the evidence underlying the conclusion statement(s), and
- recommending future research.
Please visit the NESR website for more information about NESR and its methodology.
The Committee has created protocols to describe how it will apply NESR’s systematic review methodology to answer prioritized scientific questions. A protocol includes an analytic framework, inclusion and exclusion criteria, and a synthesis plan which the Committee has tailored to the question. Each protocol is created before the Committee examines any evidence, and is made publicly available through NESR’s website.
The public is encouraged to submit written comments to the Committee on topics relevant to its work, including on its protocols. Additional systematic review protocols will be posted to the NESR website after the full Committee has had an opportunity to review and discuss during the next public meeting.