["Agribusiness, EarlyView. ", "\nABSTRACT\nMarket‐based nutrition policies, including interpretative labeling systems and taxes on sugar‐sweetened beverages (SSBs), have been widely adopted across Latin America to influence dietary choices and address rising obesity rates. While prior research documents change in food purchasing and product reformulation following these policies, evidence on their association with population‐level health outcomes remains limited. This study examines adult body mass index (BMI) responses to interpretative food labeling systems and SSB taxation policies in Mexico, Chile, and Ecuador between 2008 and 2020 using country‐level panel data. We apply complementary quasi‐experimental methods, namely synthetic control methods (SCM) and difference‐in‐differences (DID), to compare observed BMI trajectories with counterfactual outcomes. Across countries and methods, observed BMI closely tracks synthetic and matched control counterparts, indicating that aggregate BMI responses are modest in magnitude. At the same time, the analysis reveals small, heterogeneous, and gradual deviations that emerge over time and differ across policy settings. SCM results show mild mid‐term adjustments in Chile and Ecuador and near‐parallel trends in Mexico following the 2014 SSB tax. DID estimates similarly indicate small and statistically imprecise average effects after accounting for country heterogeneity and trends. Overall, the findings suggest that targeted market‐based nutrition policies can influence BMI at the margin through gradual food‐system and consumer adjustments, but that their population‐level effects are likely to remain modest when implemented in isolation."]