Impacts of school nutrition and physical activity policies on weight status among high school students

BACKGROUND: Numerous nutrition and physical activity (PA) related policies have been adopted in schools in an effort to reduce childhood obesity. However, there is a dearth of evidence that these school policies have improved students' weight status. SIGNIFICANCE: The findings will fill knowledge gaps in school policy impacts on students' weight status. PURPOSE: This study examines whether and which school policies are associated with students' weight status. METHODS: The analysis uses data collected from state-representative schools and students. The state-level measures of nutrition and PA related school policies are from the 2008 School Health Profiles data (N=4,903 schools). The individual-level data include state-representative high school students (N=67,856) who participated in state Youth Risk Behavior Surveys in 2009. RESULTS: Schools had an average of 7 nutrition-related policies. Approximately 41% of schools required physical education (PE) for all grades, and 58% of high schools offered intramural sports activities. The average number of nutrition-related school policies, the percentage of schools requiring PE for all grade levels, and the percentage of schools offering sports teams or activities of a state was associated with a lower likelihood of obesity (odds ratio (OR) =0.91 per nutrition policy, OR=0.78 per 10% increase, and OR=0.42 per 10% increase, respectively), controlling for an individual's age, gender, race/ethnicity, and clustering of students in states. CONCLUSION: The results suggest that school policies reinforcing healthy diet habits, requiring PE for students of all grade levels, and providing intramural sports opportunities have a positive influence on weight status among high school students