Associations between access to food stores and adolescent body mass index.

BACKGROUND: Environmental factors such as the availability of local-area food stores may be important contributors to the increasing rate of obesity among U.S. adolescents.
METHODS: Repeated cross-sections of individual-level data on adolescents drawn from the Monitoring the Future surveys linked by geocode identifiers to data on food store availability were used to examine associations between adolescent weight and the availability of four types of grocery food stores that include chain supermarkets, nonchain supermarkets, convenience stores, and other grocery stores, holding constant a variety of other individual- and neighborhood-level influences.
RESULTS: Increased availability of chain supermarkets was statistically significantly associated with lower adolescent Body Mass Index (BMI) and overweight and that greater availability of convenience stores was statistically significantly associated with higher BMI and overweight. The association between supermarket availability and weight was larger for African-American students compared to white or Hispanic students and larger for students in households in which the mother worked full time.
CONCLUSIONS: Economic and urban planning land use policies which increase the availability of chain supermarkets may have beneficial effects on youths' weight outcomes.