Berger, Aaron2020-11-172020-11-172020-03https://hdl.handle.net/11299/217164University of Minnesota Ph.D. dissertation. March 2020. Major: Epidemiology. Advisors: Rachel Widome, Darin Erickson. 1 computer file (PDF); viii, 122 pages.School policies can potentially impact healthy youth development trajectories. This dissertation focused on evaluating two specific types of policies: 1) School district mandated start times for high schools, and 2) School food service policies that are mandated at the federal level. The first two manuscripts examine changes in health or health-related behaviors following a delay in high school start times. A cohort of students at five Minnesota high schools was followed over three years. All schools started at either 7:30am or 7:45am at the Baseline wave of data collection, when the students were in 9th grade. Beginning the year of 10th grade, and continuing through 11th grade, two of the schools delayed their start times by 50 and 65 minutes. In the first manuscript, I assessed if the delay in school start time that was implemented in two schools was associated with changes in adolescent depressed mood. Delaying school start time was not associated with changes in depressed mood score, high risk of depression, or incident high risk of depression, over two years of follow-up. The second manuscript assessed if school start time shifts affected physical activity levels, electronic screen time, or participation in organized sports or extracurricular activities. Later school start times were not associated with changes in any of these outcomes. The final manuscript evaluated whether a national school meal policy, the Healthy, Hunger-Free Kids Act of 2010 (HHFKA), affected children's dietary quality. I used a short dietary panel study to evaluate whether participation in school meals, or the dietary effects of school meals, changed during implementation of the HHFKA. I found that children reported the same percent of calories from school meals during HHFKA implementation, compared to the years before its passage. I found that the dietary benefits from school food increased substantially, compared to before HHFKA passage. Implementation of the HHFKA measurably improved average dietary quality of all US children. Understanding the effects of childhood programs and policies is important for setting children on a healthy life trajectory. The universal, compulsory nature of schools makes them a promising setting for a population approach to health promotion.enHealthy youth developmentMental healthNatural experimentNutritionSchoolSleepThesis or Dissertation