WIC Participation and Children’s Health Outcomes

An alarming number of children from low-income households are at risk of harmful health outcomes associated with a poor diet. Chronic diseases like obesity and diabetes impact nearly 15 million children and adolescents in the U.S.

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) is a federal-state partnership that provides nutritious supplemental foods to low-income pregnant and breastfeeding women, infants, and children up to age 5; education on healthy eating; and referrals for social services. The U.S. Department of Agriculture’s (USDA’s) Food and Nutrition Service (FNS), which administers WIC, launched a study to learn how WIC participation influences children’s dietary outcomes. This study—the WIC Infant and Toddler Feeding Practices Study-2 (WIC ITFPS-2)—follows children originally enrolled in WIC around the time of birth through 6 years and then checks in on them at age 9. Westat’s Christine Borger, Ph.D., Principal Investigator of the study, explains the study and its emerging findings.

Q: What is the study designed to explore?

A: The study looks at caregivers’ decisions about child feeding, including breastfeeding, and children’s dietary outcomes, including factors associated with early childhood weight gain. More recently, it examines association between duration of WIC participation and children’s dietary intakes.

Q: How are the data collected to get to these factors of interest?

A: So far, through age 6, we’ve conducted 44,000+ telephone interviews with approximately 4,400 caregivers. We interview them by telephone up to 19 times by the time their child is age 9, and most interviews include a 24-hour dietary recall. The interviews focus on child feeding practices, caregiver attitudes and knowledge, and perceptions of WIC services. Participants also take their child to a WIC clinic or to a medical professional to complete a postage-paid card with the child’s height and weight. The participant sends the card back to Westat.

Q: What strategies does Westat use to ensure we are collecting comprehensive data?

A: First, Westat statisticians implemented a novel sampling approach, which involved accessing sites in a particular window of time to get the optimum sample to follow over time. To implement the plan, we established partnerships with WIC state agencies and sampled WIC sites. We, then, administered key informant interviews with staff to get the “lay of the land” at a macro level.

The next important piece, and perhaps the one that really demonstrated Westat’s creativity in engaging participants in a long-term study, was how we incentivized participation. We used the standard monetary approaches for enrollment and early participation, but we knew, because this is a highly mobile population, we needed to implement another strategy to keep them engaged and willing to take surveys repeatedly over a long period of time. Our strategy was simple: build strong relationships with participants by staying in contact even when they were not being interviewed. Every few months, we reached out to our respondents, touching base with them for their latest contact information. It really was a game-changer in keeping participants involved with the study, whether or not they were still participating in WIC. When needed, our strong partnerships with WIC sites also served as a key network in keeping in contact with study participants.

When the pandemic occurred, we had established trusted relationships with respondents and didn’t miss a beat. Because the survey is a telephone survey, we were able to get caregivers on the telephone and continue the conversation since the last interview. We had alternate protocols ready in place to be able to gather child height and weight measurements, but those were not needed since the data collection window was slightly extended and the lockdown was lifted.

Cooperation rates for the study are truly impressive, so much so that during the course of the study, FNS extended it multiple times so that Westat could continue collecting and analyzing the useful data. Originally slated to follow children to age 2, the study was extended to age 3, then ages 4 and 5, and then age 6, and then a follow-up at age 9 was added. Our ability to rapidly adapt to these changing goals is testament not only to our ability to keep the sample engaged and provide FNS with valuable information but also to our flexibility and our collaborative relationships with all stakeholders.

Behind the scenes, Westat’s expert dietary team met the challenge of how foods consumed change over time—particularly over the course of the first 9 years of life and during a pandemic. Our dietary team was able to bridge biennial releases of the Food and Nutrient Database for Dietary Studies (FNDDS) to accurately reflect new foods, portions, and nutrient values. This was invaluable for maintaining continuity for reporting throughout the study while accurately reflecting foods consumed.

Q: What are some key findings?

A: The findings are quite positive. Breastfeeding rates have risen since the last study in the mid-1990s. WIC is a trusted source of information. And, data show that children who stay with the program through age 3 have better diet quality than children who leave after their first year, which means that those who participate longer are on healthier trajectories. The findings also indicate that dietary benefits may continue through age 5 for those who stay with the program. These benefits and others speak directly to ways in which WIC supports the nutrition security of participants.

Learn more about the findings:

• Prenatal and Postnatal Experiences Predict Breastfeeding Patterns in the WIC Infant and Toddler Feeding Practices Study-2.
• The Relationship Between Breastfeeding and Initial Vegetable Introduction with Vegetable Consumption in a National Cohort of Children Ages 1–5 Years from Low-Income Households.
• Duration of Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) Participation Is Associated With Children’s Diet Quality at Age 3 Years,
• Duration of WIC Participation and Early Feeding Practices Are Associated With Meeting the Added Sugars Recommendation at Age 3 Years.
• Shifts in Sources of Food But Stable Nutritional Outcomes Among Children in the Early Months of the COVID-19 Pandemic.
• The WIC Infant and Toddler Feeding Practices Study-2 (WIC ITFPS-2) Through Age 5: What We’ve Learned, What Questions Remain, and How You Can Use This Longitudinal Dataset.
• Duration of WIC Participation and Early Feeding Practices Are Associated with Meeting the Added Sugars Recommendation at Age 3 Years.