Work Under Way

Purpose

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

Federal staff will analyze data sets and deliver the findings to the Committee to inform results and conclusions made by the Committee in its 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 and/or ethnicity, and culture.

Plan

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. 

Date Posted	Topic	Status	Download
July 18, 2023	Data analysis plan	Updated February 6, 2024

_{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 Sources

 

A collection of Federal data sources informs the Committee’s work. Each of these data sources is described below.

Data Source	Supporting Agencies	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 

The COVID-19 pandemic led to data collection disruptions for key Federal surveys that provide nutrition-related data, including WWEIA and NHANES.  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 conducted an evidence scan. The evidence scan, which is linked below, explored the research question: “What evidence has been published on the patterns of food and beverage intake from March 2020 to December 2022, including potential changes in dietary intake due to COVID-19 (Coronavirus Disease 2019)?”  Few studies examined dietary intakes from March 2020 to December 2022, suggesting that the COVID-19 pandemic may have impacted Federal and non-Federal data collection.

Date Posted	Topic	Status	Download
February 6, 2024	Dietary Intake Datasets in the United States from March 2020 to December 2022: An Evidence Scan	Added February 6, 2024

 

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
   

Purpose

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

• 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 the USDA 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.

Protocols

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. Any additional food pattern modeling protocol 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 discussions on recently posted protocols, view the Food Pattern Modeling and Data Analysis Subcommittee presentation from Meeting 4. 

Date Posted	Topic	Status	Download
May 31, 2023	Should foods and beverages with lower nutrient density (i.e., those with added sugars, saturated fat, and sodium) contribute to item clusters, representative foods, and therefore the nutrient profiles for each food group and subgroup used in modeling the USDA Dietary Patterns?	Updated February 6, 2024
October 19, 2023	What are the differences between nutrient profiles calculated using the dietary intakes of the total U.S. population and population subgroups?	Updated February 6, 2024
October 16, 2023	What are the implications for nutrient intakes when modifying the Protein Foods group and subgroup quantities within the Healthy U.S.-Style Dietary Pattern or Healthy Vegetarian Dietary Pattern? What are the implications for nutrient intakes when proportions of animal-based Protein Foods subgroups are reduced and proportions of plant-based Protein Foods subgroups are increased?	Updated February 6, 2024
October 16, 2023	What are the implications for nutrient intakes when modifying the Dairy and Fortified Soy group quantities within the Healthy U.S.-Style Dietary Pattern? What are the implications for nutrient intakes when Dairy food and beverage sources are replaced with non-Dairy alternatives?	Updated  February 6, 2024
October 16, 2023	What are the implications for nutrient intakes when modifying the quantities of the Grains group within the Healthy U.S.-Style Dietary Pattern? What are the implications for nutrient intakes when specific individual staple grains are emphasized; or when Grains are replaced with other staple carbohydrate foods (i.e., Starchy Vegetables; Beans, Peas, and Lentils; starchy Red and Orange vegetables)?	Updated  February 6, 2024
February 6, 2024	What are the implications for nutrient intakes when modifying the Vegetables food group and subgroup quantities within the Healthy U.S.-Style Dietary Pattern?	Added February 6, 2024
February 6, 2024	What are the implications for nutrient intakes when modifying the Fruits food group quantities within the Healthy U.S.-Style Dietary Pattern?	Added February 6, 2024
February 6, 2024	What are the implications for nutrient intakes when animal sources of foods and beverages contributing to the Dairy and Fortified Soy Alternatives and Protein Foods groups and subgroups are removed or replaced with plant sources within the Healthy Vegetarian Dietary Pattern?	Added February 6, 2024
February 6, 2024	What quantities of foods and beverages lower in nutrient density can be accommodated in the USDA Dietary Patterns while meeting nutritional goals within calorie levels?	Added February 6, 2024
February 6, 2024	Do simulated diets that meet the updated USDA Dietary Patterns and reflect variation in dietary intakes achieve nutrient adequacy?	Added February 6, 2024

_{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).

Purpose

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

• 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.

Protocol

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.