Obesity is a major public health problem in the United States owing to its substantial mortality and morbidity and increased health care costs. In response to the increasing rates of obesity in all subgroups of the population, particularly among socially and economically deprived subpopulations, researchers have begun to analyze how people’s social and physical environment might influence eating behavior, activity level, and weight status. The retail food and built environments have been identified as key components of the “obesogenic” environment, which might constitute an important determinant of the obesity epidemic . Even though the literature is not entirely consistent, there is growing evidence that physical access to different kinds of food outlets significantly influences dietary patterns and weight status at the population level. Previous studies have found that a high density of fast food restaurants in neighborhoods was associated with regular consumption of fast food and a higher prevalence of obesity.In recent studies in Canada and the US, the “Retail Food Environment Index,” defined as the ratio of the number of healthy vs. unhealthy food outlets within a certain boundary around the consumer’s residence, was associated with obesity, thus supporting the hypothesis that the retail food environment has an impact on weight status .Previous research further indicated that socially and economically deprived subgroups of the population often face a less favorable retail food environment, which in turn might increase the likelihood for poor quality and energy dense nutrition, and obesity . Accordingly, it can be hypothesized that the imbalanced distribution of food outlets might be a contributor to the inequality of obesity among ethnic minorities and different socioeconomic groups.
To date, many studies separately analyzed the associations between neighborhood level deprivation and the retail food environment or between the retail food environment and either dietary behavior or weight status . However, none of them simultaneously analyzed these different associations in a single study. In addition, most previous studies have relied on self-reported height and weight and almost none used a population-based sample that represents a large geographic area including both rural and urban populations.