OBJECTIVES: Obesity is a national epidemic that imposes direct medical and indirect economic costs on society. Recent scholarly inquiries contend that obesity also contributes to global warming. The paper investigates the relationship between greenhouse gas emissions and obesity. STUDY DESIGN: Cross-sectional state-level data for the year 2010. METHODS: Multiple regression analysis using least squares with bootstrapped standard errors and quantile regression. RESULTS: States with higher rates of obesity are associated with higher CO2 and CH4 emissions (p < 0.05) and marginally associated with higher N2O emissions (p < 0.10), net of other factors. Reverting to the obesity rates of the year 2000 across the entire United States could decrease greenhouse gas emissions by about two percent, representing more than 136 million metric tons of CO2 equivalent. CONCLUSIONS: Future studies should establish clear causality between obesity and emissions by using longitudinal data while controlling for other relevant factors. They should also consider identifying means to net out the potential effects of carbon sinks, conversion of CH4 to energy, cross-state diversion, disposal, and transfer of municipal solid waste, and potentially lower energy consumption from increased sedentariness.