Timing is Everything: The Impact of School Lunch Length on Children's Body Weight

The large number of overweight children in the United States has prompted school administrators and policy makers to identify practices in schools that contribute to unhealthy weight outcomes for children and develop strategies to prevent further increases. Advocates for school nutrition reform have suggested that it is important for children to have an adequate amount of time to eat meals in school in order to maintain a healthy weight. This article examines whether the length of time children are given to eat lunch in school has an impact on their weight. I find evidence that an increase in lunch length reduces the probability a child is overweight, and this finding is robust across various econometric specifications, including a two-sample instrumental variable model and difference-in-differences model that account for the potential endogeneity of lunch length.