This research looks at census tract level characteristics of the built environment in relation to Body Mass Index (BMI) of neighborhood residents in both a cross sectional and longitudinal analyses, specifically asking how do the development density, land use diversity, street network design, park space, and transit access of neighborhoods affect obesity in young adults.

The individual data comes from the National Longitudinal Survey of Youth 1997 (NLSY) which has followed a cohort of close to 9000 respondents since 1997. Characteristics of the built environment include measures of density, diversity, design, destination accessibility, and distance to transit. This study expects to see correlations between a variety of built environment measures and BMI, obesity, and physical activity. It is expected that when controlling for socio-demographic characteristics:

- BMI will be higher in those residents who live in neighborhoods characterized by higher levels of sprawl.
- BMI will increase at a faster rate with age for stationary respondents (stayers) who live in neighborhoods characterized by higher levels of sprawl.
- BMI will increase in those respondents who have moved (movers) to neighborhoods characterized by higher levels of neighborhood sprawl. 
- BMI will decrease for those moving in the opposite direction.