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Data analysis is the use of statistical methods to analyze national datasets to describe the current health and dietary intakes in the United States.

Why use data analysis?

The data analysis approach helped the 2025 Dietary Guidelines Advisory Committee ensure that its recommendations are practical, relevant, and achievable. The Committee applied a health equity lens to examine data in consideration of a variety of sociodemographic groups including age/life stage, sex, race and/or ethnicity, and socioeconomic position (e.g., family income, poverty to income ratio, education, food security).

Who conducted data analyses?

The federal data analysis team supported the Committee by analyzing requested data on specific topics and questions and delivering the data analysis results to the Committee. The interagency team included expert scientists with advanced degrees in nutrition, statistics, and epidemiology from agencies across the U.S. Departments of Health and Human Services and Agriculture. The Committee reviewed and synthesized the results to inform the findings and advice in its Scientific Report.

How did the Committee use data analysis?

The Committee used data analysis to describe the current state of the diet and health in the United States, including:

• Current patterns of food and beverage consumption;
• Current intake of food groups, nutrients, and dietary components;
• Prevalence of nutrition-related chronic health conditions; and
• Nutrients and/or dietary components of public health concern.

The Committee integrated evidence from its data analysis, food pattern modeling, and systematic review to inform its advice. Data on current dietary intakes were considered by the Committee in developing advice for food group and subgroup amounts in the Dietary Patterns to ensure its advice was realistic.

The Committee provided plans online and gave updates on its work, including presenting draft conclusion statements, during its public meetings. The public was encouraged to submit written comments to the Committee throughout its work.

A methodology used to: 

• develop quantitative dietary patterns that reflect health-promoting patterns identified in systematic reviews that meet energy and nutrient needs 
• illustrate how changes to the amounts or types of foods and beverages in a dietary pattern might affect an individual’s ability to meet nutrient needs

Why use food pattern modeling?

Food pattern modeling allows the Committee to provide advice to inform the development of healthy dietary patterns for the U.S. population that meet energy and nutrient needs. This approach enables the Dietary Guidelines for Americans (Dietary Guidelines) to better reflect the variety of foods and beverages and the range of possible healthy diets within the diverse U.S. population.

Who conducted food pattern modeling analyses?

The federal food pattern modeling team supported the work of the Committee by conducting specific analyses identified by the Committee. The interagency team included nutrition scientists, data analysts, and registered dietitians from USDA and HHS who have advanced degrees in nutrition science, public health, economics, or related fields and expertise in food pattern modeling methodology. The Committee reviewed and synthesized the findings to inform conclusions and provide advice in its Scientific Report.

How did the Committee use food pattern modeling?

The Committee used food pattern modeling to understand how hypothetical changes to existing patterns would impact the ability to meet nutrient needs across the population. The Committee used all three approaches to answer this overarching scientific question, which informs its advice to the Departments:

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, preferences, or needs of the diverse communities and cultural foodways within the U.S. population?

The Committee provided protocols online and gave updates on its work, including presenting draft conclusion statements, during its public meetings. The public was encouraged to submit written comments to the Committee throughout its work.
 

A systematic review conducted using Nutrition Evidence Systematic Review (NESR) methodology 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.

Why use systematic reviews?

Systematic reviews allow high priority scientific questions to be answered by reviewing evidence from all relevant studies published on a particular topic, rather than relying on individual studies with particular findings, or conducted in certain populations.

The findings of individual studies depend on many variables that can change from study to study. Systematic reviews, on the other hand, make conclusions based on evidence from all relevant studies and consider their similarities, differences, strengths, and limitations. 

Who conducted systematic reviews?

The Committee conducted its systematic reviews with support from USDA’s NESR Branch. NESR is a team of career federal scientists made up of trained systematic review analysts and librarians. NESR analysts have doctoral or master’s degrees in nutritional science, public health, biochemistry, biology, or biostatistics. Some are registered dietitians. NESR librarians have master’s degrees in library and information science, and experience with biomedical topics. The Committee is responsible for establishing protocols and synthesizing the evidence to develop conclusion statements and grade the strength of the evidence.

How did the Committee conduct systematic reviews?

The Committee 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 tailored to the question. Each protocol was created before the Committee examined any evidence, and was made publicly available through NESR’s website, NESR.usda.gov. 

Once protocols were established, the Committee used NESR’s rigorous and transparent methodology to conduct and/or update systematic reviews. NESR’s systematic review methodology involves: 

• searching for and, screening articles, 
• extracting data from and assessing the risk of bias of each included article, 
• synthesizing the evidence, 
• developing conclusion statements, 
• grading the evidence underlying the conclusion statement(s), and 
• recommending future research. 

The Committee provided protocols online and gave updates on its work, including presenting draft conclusion statements, during its public meetings. The public was encouraged to submit written comments to the Committee throughout its work.