Prospective associations between neighborhood features and body mass index in Montreal adolescents.

Purpose: To investigate the association between the neighborhood built environment and trajectories of body mass index (BMI) in youth. Methods: Data were collected in a prospective study of 1293 adolescents in Montreal. Built environment variables were obtained from public databases for road networks, land use, and the Canadian Census. Anthropometric data were collected when participants were ages 12.5, 15 and 17 years. We undertook hierarchical cluster analysis to identify contrasting neighborhood types based on features of the built environment (e.g., vegetation, population density, walkability). Associations between neighborhood type and trajectories of BMI z -score (BMIz) were estimated using multivariable linear mixed regression analyses, stratified by sex. Results: We identified three neighborhood types: Urban , Suburban , and Village . In contrast to the Urban type, the Suburban type was characterized by more vegetation, few services and low population density. Village and Suburban types were similar, but the former had greater land use diversity, population density with more parks and a denser food environment. Among girls, living in Urban types was associated with decreasing BMIz trajectories. Living in Village types was associated with increasing BMIz trajectories. No associations were observed among boys. Conclusions: Neighborhoods characterized by greater opportunities for active living appear to be less obesogenic, particularly among girls.