Influence of SNAP Participation and Food Environment on Nutritional Quality of Food at Home Purchases

A growing body of research describes how individuals make food shopping decisions in both time and space. The FoodAPS dataset provides a unique opportunity for understanding these patterns among a large sample across income, SNAP status, and settings. We addressed three questions in our research: (1) Where do participants shop for food at home (FAH) and how do individual characteristics interact with store characteristics and distance? (2) How does the nutritional content of foods purchased change as time from SNAP distribution increases? and (3) How does store choice influence the nutritional quality of FAH purchases? We used a conditional logit model to answer the first question, determining that overall, participants choose full-service supermarkets, larger stores, and stores closer to home but that store choice is influences by SNAP status, ethnicity, race, sex, car ownership and the level of urbanization of the county of residence. For the second question, we used general linear modeling to determine changes over time in dietary quality of FAH purchases, as measured by composite Health Eating Index (HEI) score. We found an increase in HEI-2010 score in the days immediately following SNAP distribution followed by a decrease until 20 days after distribution and then a moderate increase to the end of the SNAP-cycle. For the final question, we used a generalized estimating equation (GEE) model for repeated-measures to analyze the impact of store type on composite HEI score of FAH events. We found that purchases made at limited assortment stores had significantly higher HEI scores while dollar stores had significantly lower HEI scores than purchases at conventional supermarkets. Participating in SNAP had significant positive impact on composite HEI scores, relative to households income-eligible for SNAP but not participating. These results require closer consideration but have important implications for policies relating to what types of foods stores should be subsidized, through healthy food financing initiatives and SNAP and WIC authorization, and the way SNAP benefits are distributed over the course of the month