Wealth and weight revisited: A Bayesian model averaging approach to the Obesity Kuznets Curve.

The substantial literature on the existence of an inverted U-shaped relationship between obesity prevalence and economic growth, known as the Obesity Kuznets Curve (OKC), has yielded mixed evidence due to uncertainty in model and variable selection. We address this using a comprehensive panel of 84 countries from 2000 to 2020. Our Two-Way Fixed Effects (TWFE) models suggest the OKC follows an inverted-N shape, suggesting multiple transition points in the obesity-wealth nexus. To account for model uncertainty, we employ Bayesian Model Averaging (BMA) against a large set of potential determinants. The inverted-N shape remains robust, with BMA identifying key predictors across economic, sociocultural, and environmental domains. Our results suggest that a single 'turning point' oversimplifies the obesity transition, and that targeted interventions must account for the multi-stage nature of economic development.