Environmental factors associated with obesity in the adult population in a medium-sized Brazilian cityFactores ambientales asociados a la obesidad en una población adulta de un municipio brasile?o de tama?o medio

摘要

The aim of this study was to estimate associations between environmental variables and obesity in the adult population in a medium-sized Brazilian city. This was a cross-sectional study with individual data from a population-based study and environmental data obtained by direct observation, later georeferenced by the addresses. The sample included 965 adults 20 to 59 years of age, and the study used anthropometric, socioeconomic, demographic, behavioral, and self-rated health data. The outcome variable was obesity, defined as body mass index (BMI) ≥ 30kg/m 2 . Retail food outlets were classified as: supermarkets and establishments with a predominance of healthy, unhealthy, and mixed foods. Settings for physical activity were categorized as public and private. Characterization of the social environment used the census tracts’ per capita income in tertiles and the crime rate. Binary logistic regression analysis was performed according to the generalized estimating equations model. An inverse association was found between density of public and private locations for physical activity and obesity (OR = 0.95, 95%CI: 0.92-0.99; OR = 0.98, 95%CI: 0.97-0.99) in models adjusted by individual and environmental variables. In all the models, the highest per capita income tertile was inversely associated with obesity (p ≤ 0.05). The food environment and crime rates were not independently associated with obesity. These findings suggest that the census tract’s income and its environment for physical activity can orient public policies to decrease obesity in this city.