Greenspace utilization and obesity burden in urban America: Multi-city analysis with validation in a clinical cohort

OBJECTIVES: Greenspace engagement is a crucial environmental determinant of obesity, yet evidence remains mixed across urban contexts. Most studies use static measures of greenness, which may mischaracterize pathways through which greenspace influences obesity. This study explores how greenspaces affect obesity across major U.S. metropolitan areas (MSAs) and how these effects vary across cities. STUDY DESIGN: Cross-sectional ecological analysis of census tract-level data across nine U.S. metropolitan areas, with validation using a clinical cohort from the Houston Methodist Cardiovascular Disease Learning Health System Registry. METHODS: Census tract-level data across nine U.S. MSAs were analyzed, integrating greenspace visits, adult obesity prevalence, vegetation (NDVI), demographics, food deserts, and health covariates. Linear models (OLS) estimated adjusted associations, while multiscale geographically weighted regression (MGWR) models assessed neighborhood-level variation. Results were validated using patients' Body Mass Index (BMI) data from the Houston Methodist Registry. RESULTS: The analytic sample included over 15,000 tracts across nine MSAs. In adjusted OLS models, seven MSAs demonstrated inverse associations, with Houston exhibiting the strongest. MGWR analyses revealed substantial within-metro heterogeneity across all MSAs, reflecting neighborhood context, particularly in relation to density, nutrition, and structural constraints. In the Houston Methodist cardiovascular cohort (n = 1,049,782), higher visitation was associated with lower obesity burden. Each additional visit was associated with lower odds of obesity across BMI levels, demonstrating a consistent association across increasing levels of severity. CONCLUSIONS: Across U.S. metros, greater greenspace engagement was generally associated with lower obesity prevalence, though associations were not spatially uniform. These findings highlight the importance of actual greenspace use and local context in evaluating the role of urban environments in shaping obesity risk.