Search

Food environments can contribute to excess weight gain among adults, but the evidence is mixed.This longitudinal study investigates the association between changes in the food environment and changes in body mass index (BMI) in adults and whether changes in the food environment differentially impact various subgroups.At two time points, BMI was calculated using self-reported height and weight data from 517 adults (mean age, 41 years) living in four New Jersey cities. The count of different types of food outlets within 0.4, 0.8, and 1.6 km of respondents' residences was collected at baseline and tracked until follow-up. A binary measure of social standing (social advantage, n = 219 vs social disadvantage, n = 298) was created through latent class analysis using social, economic, and demographic variables. Multivariable linear regression modelled the association between changes in BMI with measures of the food environment; additionally, interaction terms between the measures of social standing and the food environment were examined.Overall, over 18 months, an increase in the number of small grocery stores within 0.4 km of a respondent's residence was associated with a decrease in BMI (β = -1.0, 95% CI: -1.9, -0.1, P = 0.024), while an increase in the number of fast-food restaurants within 1.6 km was associated with an increase in BMI (β = 0.1, 95% CI: 0.01, 0.2, P = 0.027). These overall findings, however, masked some group-specific associations. Interaction analyses suggested that associations between the food environment and change in BMI vary by social standing. For instance, the positive association between changes in fast-food restaurants and changes in BMI was only observed in the social disadvantage group (β = 0.1, 95% CI: 0.02, 0.2, P = 0.021).In a sample of adults living in New Jersey, changes in food environment had differential effect on individuals' BMI based on their social standing.