This paper investigates the effects of food imports on obesity in Mexico. Exploiting variation across Mexican states in their exposure to food imports from the U.S., we find that imports of unhealthy foods significantly contribute to the rise of obesity in Mexico. The empirical evidence also suggests that unhealthy food imports widen health disparities between skilled and unskilled Mexican women. By linking imports to food expenditure and obesity, the paper sheds light on an important channel through which trade liberalisation can affect health.