Food delivery services for enhancing participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in the United States: bridging the WIC-eligible access gap

Background Diet-related health disparities among U.S. children persist despite the availability of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) benefits to eligible women, infants, and children. Participation remains suboptimal: only 51.2% of eligible individuals were enrolled in 2021. Transportation and food-environment constraints pose salient barriers, especially for caregivers of infants in food deserts. Emerging online ordering and delivery options may reduce access frictions, but grocery delivery coverage is limited, and fees are often not covered by benefits. Methods We linked USDA Food and Nutrition Service state-level WIC participation data (November 2024 vs. September 2025) with demographic, economic, and political indicators to examine whether food retail delivery availability is associated with changes in WIC participation and whether this association varies by poverty and unemployment context. Delivery availability was coded as a binary indicator based on state announcements of online ordering/delivery pilots. Descriptive statistics characterized cross-state variation. Ordinary least squares models with robust standard errors were used to test associations, including an interaction between delivery availability and the poverty and unemployment rates; marginal predictions visualized the interaction. Results Only 2 of 50 states (4%) had active WIC online ordering/delivery options during the study window. The average percentage change in participation rate was modest (mean = 1.23; SD = 2.70). In the baseline model, the poverty rate was positively associated with the change in participation ( β = 0.62, p < 0.05). Adding the interaction improved model fit (R 2 = 0.47) and revealed a significant positive moderation: states with delivery experienced larger gains in participation as poverty increased (Delivery × Poverty β = 11.83, p < 0.001) or as the unemployment rate increased (Delivery × Unemployment β = 6.56, p < 0.001). Other covariates were not statistically significant. Margins plots showed that at higher poverty levels (>15%), predicted participation gains in delivery states exceeded those in non-delivery states by more than 75 percentage points. Margins plots also indicated that when unemployment rates rise above 5%, the expected increase in participation in delivery states is more than 10 percentage points higher than in non-delivery states. Conclusion WIC-eligible food delivery availability is associated with greater increases in participation in higher-poverty states or higher-unemployment states, suggesting that modernization can mitigate structural access barriers for families with young children. Policy actions, such as subsidizing delivery fees, expanding retailer participation, and providing digital access supports, could enhance equitable reach. Future work should leverage longitudinal and individual-level data to test mechanisms, evaluate fee-subsidy pilots, and assess heterogeneity by rurality, race/ethnicity, and family structure.