Food prices, access to food outlets and child weight

This study examines the importance of food prices and restaurant and food store outlet availability for child body mass index (BMI). We use the 1998, 2000 and 2002 waves of the child-mother merged files from the 1979 cohort of the National Longitudinal Survey of Youth combined with fruit and vegetable and fast food price data obtained from the American Chamber of Commerce Researchers Association and outlet density data on fast food and full-service restaurants and supermarkets, grocery stores and convenience stores obtained from Dun & Bradstreet. Using a random effects estimation model, we found that a 10% increase in the price of fruits and vegetables was associated with a 0.7% increase in child BMI. Fast food prices were not found to be statistically significant in the full sample but were weakly negatively associated with BMI among adolescents with an estimated price elasticity of -0.12. The price estimates were robust to whether we controlled for outlet availability based on a per capita or per land area basis; however, the association between food outlets and child BMI differed depending on the definition. The associations of fruit and vegetable and fast food prices with BMI were significantly stronger both economically and statistically among low- versus high-socioeconomic status children. The estimated fruit and vegetable and fast food price elasticities were 0.14 and -0.26, respectively, among low-income children and 0.09 and -0.13, respectively, among children with less educated mothers.