The food environment and adult obesity in US metropolitan areas

This research examines the larger-scale associations between obesity and food environments in metropolitan areas in the United States (US). The US Census County Business Patterns dataset for 2011 was used to construct various indices of food environments for selected metropolitan areas. The numbers of employees engaged in supermarkets, convenience stores, full service restaurants, fast food restaurants, and snack/coffee shops were standardised using the location quotients, and factor analysis was used to produce two uncorrelated factors measuring food environments. Data on obesity were obtained from the 2011 Behavioral Risk Factor Surveillance System. Individual level obesity measures were linked to the metropolitan area level food environment factors. Models were fitted using generalised estimating equations to control for metropolitan area level intra-correlation and individual level sociodemographic characteristics. It was found that adults residing in cities with a large share of supermarket and full-service restaurant workers were less likely to be obese, while adults residing in cities with a large share of convenience store and fast food restaurant workers were more likely to be obese. Supermarkets and full-service restaurant workers are concentrated in the Northeast and West of the US, where obesity prevalence is relatively lower, while convenience stores and fast-food restaurant workers are concentrated in the South and Midwest, where obesity prevalence is relatively higher. The food environment landscapes measured at the metropolitan area level explain the continental-scale patterns of obesity prevalence. The types of food that are readily available and widely served may translate into obesity disparities across metropolitan areas.