Investigators will conduct a quantitative meta-analysis of the literature on built environment characteristics as determinants of physical activity and obesity. This research synthesis project will include published literature on the relevance of the built environment to physical activity or obesity in the US between 1995 and 2010. This focus will be on the patterns of association observed across the life course, across socioeconomic and demographic groups, and across study settings. The proposed project will advance our understanding of the complementary and intersection roles of the built environment and social context in shaping physical activity and obesity across the lifespan. The findings from this project will be made accessible to a range of academic researchers, public health practitioners, urban planners, public agencies, and community groups.