Neighborhood food environment and walkability predict obesity in New York City.

Background: Differences in the neighborhood food environment may contribute to disparities in obesity.
Objectives: The purpose of this study was to examine the association of neighborhood food environments with body mass index (BMI) and obesity after control for neighborhood walkability.
Methods: This study employed a cross-sectional, multilevel analysis of BMI and obesity among 13,102 adult residents of New York City. We constructed measures of the food environment and walkability for the neighborhood, defined as a half-mile buffer around the study subject's home address.
Results: Density of BMI-healthy food outlets (supermarkets, fruit and vegetable markets, and natural food stores) was inversely associated with BMI. Mean adjusted BMI was similar in the first two quintiles of healthy food density (0 and 1.13 stores/km2, respectively), but declined across the three higher quintiles and was 0.80 units lower [95% confidence interval (CI), 0.27-1.32] in the fifth quintile (10.98 stores/km2) than in the first. The prevalence ratio for obesity comparing the fifth quintile of healthy food density with the lowest two quintiles combined was 0.87 (95% CI, 0.78-0.97). These associations remained after control for two neighborhood walkability measures, population density and land-use mix. The prevalence ratio for obesity for the fourth versus first quartile of population density was 0.84 (95% CI, 0.73-0.96) and for land-use mix was 0.91 (95% CI, 0.86-0.97). Increasing density of food outlets categorized as BMI-unhealthy was not significantly associated with BMI or obesity.
Conclusions: Access to BMI-healthy food stores is associated with lower BMI and lower prevalence of obesity.