Universal Free School Meals Policy and Childhood Obesity.

Background And Objectives: The Community Eligibility Provision (CEP), a universal free school meals policy, increases school meal participation by allowing schools in low-income areas to provide free breakfast and lunch to all students; however, its impact on obesity remains uncertain. The objective of this study is to estimate the association of CEP with child obesity.

Methods: School obesity prevalence was calculated using BMI measurements collected annually between 2013 and 2019 from students in California public schools in grades 5, 7, and 9. To estimate the association of CEP with obesity, we used a difference-in-differences approach for staggered policy adoption with an outcome regression model conditional on covariates, weighted by student population size.

Results: The analysis included 3531 CEP-eligible schools using school-level obesity prevalence calculated from 3 546 803 BMI measurements. At baseline, on average, 72% of students identified as Hispanic, 11% identified as white, 7% identified as Black, and 80% were eligible for free or reduced-price meals. Baseline obesity prevalence was 25%. Schools that participated in CEP were associated with a 0.60-percentage-point net decrease in obesity prevalence after policy adoption (95% confidence interval: -1.07 to -0.14 percentage points, P = .01) compared with eligible, nonparticipating schools, corresponding with a 2.4% relative reduction, given baseline prevalence. Meals served increased during this period in CEP-participating schools only.

Conclusions: In a balanced sample of California schools, CEP participation was associated with a modest net decrease in obesity prevalence compared with eligible, nonparticipating schools. These findings add to the growing literature revealing potential benefits of universal free school meals for children's well-being.