In this study, we evaluate the impact of unconditional family cash transfers on the body mass index (BMI) and obesity of parents. Our approach is based on the implementation of the Universal Child Care Benefit in 2006 for all children in Canada under 6 years of age. We show that the reform caused decreases in BMI and the prevalence of overweight and obesity in mothers with young children. We also report larger changes at the upper tail of the distribution of BMI in both lower-educated mothers and single mothers. In terms of fathers, we find that the policy had no impact on weight outcomes.