Population-level nutrition interventions and food environment effects on obesity

Drexel University, Philadelphia PA

Investigators

Abstract

MODIFIED PROJECT SUMMARY Childhood obesity prevalence keeps rising, especially among school-age children. Children of origins in Asia and the Pacific Islands (Asian/PI), as a whole, have lower obesity prevalence; but, at lower BMI levels, they have higher risk of obesity-related diseases relative to White peers. Asian/PI children have remained largely invisible in obesity prevention efforts, though obesity prevalence varies widely among Asian/PIs, the fastest growing demographic group. Data scarcity is a significant barrier to the design of strategies to prevent obesity for all children and reduce gaps in obesity risk. Nutrition policies—those that regulate the nutritional content of foods and beverages in schools, including the so-called “competitive” foods sold separately from school meals—could play a key role in the primary prevention of obesity and related chronic diseases. The community food environment near schools can also influence obesity (e.g., through children’s access, purchases and consumption of unhealthy foods). No studies have examined the combined influences of multiple nutrition policies and community food environments on child obesity and related heterogeneity among Asian/PI children. Using unprecedented, longitudinal BMI data on >1 million Asian/PI children, this quasi-experimental study evaluates policy and environmental effects on BMI. The first of its kind, this longitudinal study will: (1) determine the effects of federal and state nutrition policies designed to improve food and beverages in schools on obesity across eleven Asian/PI population groups; and (2) investigate how community food environments modify the effect nutrition policies on obesity. To obtain robust inferences, the study uses the best available methods to evaluate non-randomized exposures: interrupted time series design and “difference-in-difference” analysis to improve causal inferences. The study’s powerful design links longitudinal BMI measures with time-varying measures of the community food environments of all the public schools to which children attended. Expected results: This study will: (i) strengthen the evidence base by elucidating the causal effects of large scale nutrition interventions on obesity among Asian/PI populations; (ii) identify nutrition environments near schools where nutrition policies are most effective; and (iii) illuminate environments (inside and/or near schools) where additional interventions are needed. The study results have potential to inform strategies focused on two major public health goals—preventing child obesity and reducing obesity gaps across Asian/PI populations.