Skip to main content

WIC: USDA's Review of Vegetables Available under the Program Followed Leading Research Practices

GAO-18-125R Published: Nov 30, 2017. Publicly Released: Nov 30, 2017.
Jump To:
Skip to Highlights


What GAO Found

The U.S. Department of Agriculture's (USDA) review of vegetables available under the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) generally followed leading research practices for designing studies, identifying and analyzing data, and developing statistical estimates, according to GAO's analysis. USDA contracted with the National Academies of Sciences, Engineering, and Medicine (National Academies) to review vegetables available under WIC, as part of its most recent review of foods available under the program, which resulted in three reports (collectively referred to in this report as "USDA's review"). USDA's review followed leading practices for designing studies, according to GAO's analysis of the three reports. For example, researchers developed clear questions to examine the food and nutritional needs of the WIC-eligible population and used several methodologies and data sources to answer them. GAO also found that USDA's review of vegetables available under WIC followed leading practices for identifying and analyzing data. For example, researchers clearly documented the criteria they used to identify and include studies in the literature reviews, as well as the databases and search words they used. In addition, USDA's review generally followed leading practices for developing statistical estimates. Specifically, researchers developed statistical estimates that applied to WIC participants generally, not just those who were part of the survey that was analyzed. They also provided additional information about the range of possible estimates in two of the three reports that comprise USDA's review of vegetables available under WIC.

Why GAO Did This Study

WIC provides supplemental foods, nutrition education, including breastfeeding promotion and support, and health and social service program referrals to low-income pregnant, breastfeeding, and postpartum women, infants, and children up to age 5 who are found to be at nutritional risk. The foods available under WIC are designed to supplement participants' diets with specific nutrients. In fiscal year 2016, WIC provided food and services to about 7.7 million participants, and the federal government spent approximately $6 billion on the program.

Federal law requires USDA to conduct a scientific review of the foods available through WIC at least once every 10 years and amend the foods available, as necessary, to reflect nutrition science, public health concerns, and cultural eating patterns. USDA contracted with the National Academies for the most recent review, which culminated in three reports issued in 2015 and 2017.

The Consolidated and Further Continuing Appropriations Act of 2015 included a provision for GAO to audit the USDA's most recent review of the supplemental foods available under the program, including the scientific research and data used to conduct USDA's review. This report assesses the extent to which leading research practices were followed in USDA's most recent review of vegetables available under WIC.

To address this objective, GAO reviewed relevant federal laws, regulations, and guidance, and the three National Academies' reports that comprise USDA's latest review of foods available under WIC. GAO also reviewed leading research practices identified in GAO's past work, guidance for federal agencies from the Office of Management and Budget (OMB), and reports from other relevant organizations and individuals with expertise in research design. From these sources, GAO identified eight leading research practices that are relevant to the three reports that comprise USDA's review of foods available under WIC, and assessed the extent to which research conducted for each report followed the identified practices. GAO also interviewed officials from USDA and the National Academies who were responsible for the recent review of foods available under WIC.

For more information, contact Kathryn Larin or Nancy Kingsbury at (202) 512-7215 or or

Full Report

GAO Contacts

Office of Public Affairs


Child nutritionChildrenData collectionData integrityFoodFood programs for childrenFruits and vegetablesHealth careInfantsNutritionNutrition programsVegetablesWomenWomen infants and children program