We investigate the effect of household cash transfers during childhood on young adult body mass indexes (BMI). The effects of extra income differ depending on the household's initial socioeconomic status (SES). Children from the initially poorest households have a larger increase in BMI relative to children from initially wealthier households. Several alternative mechanisms are examined. Initial SES holds up as the most likely channel behind the heterogeneous effects of extra income on young adult BMI. (JEL D14, H23, H75, I12, J13, J15).