This comprehensive spatial epidemiological study investigates the complex relationships between neighborhood food environment characteristics and childhood obesity prevalence across 45 metropolitan regions. Utilizing multi-level data from 25,682 children aged 6-12 years, combined with detailed geographic information systems mapping of 12,450 food outlets, we demonstrate significant spatial clustering of obesity risk in neighborhoods with high fast-food density and limited healthy food access. After adjusting for individual and neighborhood-level confounders, each additional fast-food outlet within an 800-meter school buffer was associated with an 11% increase in obesity odds, while supermarket availability demonstrated protective effects. Spatial regression models revealed significant moderation by neighborhood socioeconomic status, with stronger food environment effects observed in low-income communities. These findings provide robust evidence for urban planning policies addressing obesogenic food environments.