A multivariate analysis of federally mandated school wellness policies on adolescent obesity

To evaluate the effects of school wellness policies mandated by the 2004 Child Nutrition and WIC Reauthorization Act on the prevalence of overweight and obesity among adolescents.

Multivariate logistic regressions, adjusted for clustering within school districts, were used to estimate the effects of district-level wellness policies on the odds of overweight and obesity among adolescents. The analyses were performed on a population-based sample obtained from the Utah Population Database, a compilation of vital characteristic, administrative, and genealogical records on all residents in Utah. Models controlled for individual, maternal, and familial characteristics, as well as characteristics of school district of residence. Self-reported body mass index was taken from drivers license data.

Each additional component included in a district's wellness policy was associated with as much as: 3.2% lower odds in the prevalence of adolescent overweight (OR = .968; 95% CI = .941-.997), 2.5% lower odds of obesity (OR = .975; CI = .952-.997), and 3.4% lower odds of severe obesity (OR = .966; CI = .938-.995). Wellness policy components related to diet were significantly associated with lower body mass indexes across all three thresholds, whereas those related to physical activity had significant associations for lower odds of severe obesity only.

Results suggest that school wellness policies can significantly reduce the risk of adolescent obesity. Further research should address specific policy components that are most effective in various populations, as well as the level of commitment that is required at both the school- and district-levels for sustained effect.