Economic Contextual Factors and Child Body Mass Index

This study examines the relationship between child weight and fast food and fruit and vegetable prices and the availability of fast food restaurants, full-service restaurants, supermarkets, grocery stores and convenience stores. We estimate cross-sectional and individual-level fixed effects (FE) models to account for unobserved individual-level heterogeneity. Data are drawn from the Child Development Supplement of the Panel Study of Income Dynamics combined with external food price and outlet density data at the zip code level. FE results show that higher fruit and vegetable prices are statistically significantly related to a higher body mass index (BMI) percentile ranking among children with greater effects among low-income children: fruit and vegetable price elasticity for BMI is estimated to be 0.25 for the full sample and 0.60 among low-income children. Fast food prices are statistically significantly related to child weight only in cross-sectional models among low-income children with a price elasticity of -0.77. Increased supermarket availability and fewer available convenience stores are related with lower weight outcomes among low-income children. These results provide evidence on the potential effectiveness of using fiscal pricing interventions such as taxes and subsidies and other interventions to improve supermarket access as policy instruments to address childhood obesity.