Expanding Exposure Can Increasing the Daily Duration of Head Start Reduce Childhood Obesity?

Coinciding with the work requirements of welfare reform in the mid-1990s, the early childhood education program, Head Start, significantly expanded to increase the availability of full-day classes. Using unique administrative data, we examine the effect of full-day compared to half-day attendance on childhood obesity. This effect is identified from changes in obesity over time and from the elimination of a state-provided full-day expansion grant that decreased the supply of full-day classes. Our results suggest that full-day Head Start attendance significantly reduces the proportion of obese children at the end of the academic year.