This paper investigates the role that aspects of the physical environment play in determining health outcomes in adults as measured by body mass index (BMI). Using spatial econometric techniques that allow for spatial spillovers and feedback processes, this research specifically examines how differing levels of access to large chain grocers has on individual health outcomes. While other studies have investigated the impact of proximity to food retailers, the point-coordinate data used in this paper is uniquely suited to spatial econometric estimation at the individual level. In addition to modeling spatial dependence and allowing for unobserved neighborhood effects, the flexibility of the model is increased by incorporating potential spatial heterogeneity between wealthier and lower-income neighborhoods. Using survey responses tied to geographic location, demographic, behavioral, and access to chain grocers, this study finds evidence of spatial dependence pointing to locational impacts on BMI. The effect on individual health outcomes of retailer access improvements varies depending on neighborhood characteristics. Our findings suggest structural differences in the variation and sensitivity of BMI dependent jointly on individual and neighborhood characteristics.