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Balancing Nutrients for Better Outcomes: From Pregnancy to Early Childhood (Oral Session 5)

(OR05-02-25) Estimating the Impact of WIC on Diet Quality Among Children 2 to 5 Years of Age Who Participated in the Infant and Toddler Feeding Practices Study-2

Sunday, June 1, 2025
8:42 AM – 8:56 AM ET
Location: S220 E-G

    Presenting Author(s)

  • Karina R. Lora, PhD RD

    Associate Professor
    The George Washington University
    Washington DC, District of Columbia, United States

    Disclosure(s): No relevant financial relationship(s) with ineligible companies to disclose.

    • Co-Author(s)

  • LH

    Leslie Hodges

    U.S. Department of Agriculture, Economic Research Service

  • YJ

    Yichen Jin

    Department of Exercise and Nutrition Sciences, Milken Institute School of Public Health, The George Washington University

Objectives: Obtain causal-like estimates of the relationship between participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and children’s diet quality using data from the WIC Infant Toddler Feeding Practices Study-2 (ITFPS-2).

Methods: Samples of 1729, 1884, 1577, 1,923, and children ages 24, 36, 48, and 60 months (t) from the WIC ITFPS-2 were used. All had some exposure to WIC. Missing values were imputed using multiple imputation by chained equations. The outcome of interest was Health Eating Index (HEI) score at age t, a measure of whether diet quality aligns with recommendations for a healthy diet in the Dietary Guidelines for Americans. The treatment was WIC participation at current and prior t. The relationship between HEI at age t and WIC participation through age t was estimated using inverse probability weighting of marginal structural models. Selection into WIC participation was addressed by weighting children in the study by the inverse of their predicted probability of WIC participation at age t conditional on their prior treatment, prior outcomes, and time-varying and invariant characteristics. Time-varying covariates were adjusted for using stabilized weights; invariant covariates (measured at baseline) were adjusted for in the marginal structural models.

Results: Average HEI scores for children in the sample were 56.7 (24 mo.), 57.5 (36 mo.), 56.9 (48 mo.), and 55.3 (60 mo.). At all ages (t), children continuously enrolled in WIC had higher HEI scores relative to children who left the program before 13 months. Compared to those continuously enrolled in WIC, average HEI scores of children who exited from WIC by 13 months were 2.7 points lower at age 24 months (p=.047), -4.8 points lower at age 36 months (p=.004), -6.2 points lower (p=.001) at age 48 months, and -5.5 points lower at age 60 months (p=0.030).

Conclusions: Our study addresses a need for research using more robust methodologies to build the evidence base for WIC’s impacts. Our findings indicate that continuous participation in WIC has a positive impact on diet quality through age 5 (60 months). Although HEI scores were higher, on average, for children enrolled in WIC, both their scores and the scores of those who exited the program indicate a need for improvement.

Funding Sources: USDA46092/3/CCNS92070F