Fast-food outlets and grocery stores near school and adolescents' eating habits and overweight in Finland.
Environmental factors may affect adolescents' eating habits and thereby body weight. However, the contribution of school neighbourhood environment is poorly understood. This study examined the association between proximity of a fast-food outlet or grocery store to school and adolescents' eating habits and overweight. Participants were 23 182 adolescents (mean age 15 years) who responded to a classroom survey in 181 lower secondary schools in Finland (2008-09). School location was linked to data on distance from school to the nearest fast-food outlet or grocery store (≤100 m, 101-500 m, >500 m) using global positioning system-coordinate databases. Outcomes were irregular eating habits (skipping breakfast, skipping free school lunch, skipping free school-provided snacks and not having family dinners), the accumulation of these habits and overweight, including obesity (body mass index ≥ 25 kg/m(2)). Thirteen percentage of the participants were overweight. Having a fast-food outlet or grocery store near school was associated with skipping often breakfast and free school lunch, and the accumulation of irregular eating habits. The proximity of a fast-food outlet or grocery store was associated with a 1.25-fold (95% confidence interval 1.03-1.52) risk of overweight among adolescent with a low socioeconomic status but not among those with higher socioeconomic status. This association was partly (12%) explained by the accumulation of irregular eating habits. Among adolescents from low socioeconomic background, the presence of fast-food retailers near schools is associated with accumulation of irregular eating habits and greater overweight. These findings suggest that obesogenic school neighbourhoods may contribute to social inequalities in overweight.