Background and significance: Obesity rates remain high, despite nationwide declines and plateaus in the overall prevalence of obesity among some groups. Crucially, Black and Latino children have higher obesity rates than non-Hispanic Whites (hereafter ?disparities?). Effective strategies to reduce child obesity and disparities could significantly contribute to population health improvements and reductions in racial/ethnic health disparities. Nutrition policies?those that regulate the nutritional content of foods and beverages in schools, including the so-called ?competitive? foods because they are sold separately from school meals? could play a key role in the primary prevention of obesity and related chronic diseases. The effect of nutrition policies however, can be strengthened or weakened by the community food environment near schools (e.g., through children?s access, purchases and consumption of unhealthy foods). No studies have yet examined the combined influences of multiple nutrition policies and community food environments on child obesity and disparities. Objectives: This quasi-experimental study is responsive to the NIH Obesity Strategic Plan and proposes to: (1) determine the obesity effects of the California nutrition policy improving and limiting access to ?competitive? foods/beverages together with the recent federal policy to improve school meal nutrition standards; and (2) investigate whether community food environments modify the effect nutrition policies on obesity and related disparities. Innovation. The study: (a) improves causal inferences about the effects of nutrition policies on obesity and disparities using rigorous, complementary methods (interrupted time series design, propensity scores, and latent class analysis, GIS); (b) simultaneously investigates the obesity effects of the nutrition policies and the surrounding school food environment; and (c) uses a longitudinal, robust (>16 million) population-based data containing objective individual-level BMI measures of diverse children (51% Latino, 6% Black, 33% White, 8% Asian) linked with the community food environments of all the public schools to which children attended in California from 2001 to 2017.
, influence on other research and expected results: Preventing obesity and eliminating health disparities are major public health goals in Healthy People 2020. This study has the potential to influence the fields of obesity prevention science, racial/ethnic health disparities, as well as nutrition policy and environmental strategies to improve overall child health. The results generated from this study will: (a) strengthen the evidence base by elucidating the causal effects of promising, large scale nutrition interventions on obesity and related disparities; (b) identify characteristics of nutrition environments near schools where such nutrition policies are most effective; and (c) illuminate environments (inside and/or near schools) where additional interventions are needed. Collectively, the study results have the potential to inform the course of health and nutrition policies to prevent obesity and reduce health disparities early in life.