The threefold increase in obesity rates for adolescents aged 12-19 over the past several decades not only has negative consequences for their health, increasing their risk for diseases such as type 2 diabetes, but for broader society as a whole, dampening the US economy due to productivity losses brought about by obesity-related diseases. Though numerous states across the US have enacted statewide legislation requiring public schools to undertake multi-pronged interventions to address obesity—including reducing the availability of “junk” foods in school cafeterias as well as increasing time allocated to physical education—rigorous evidence establishing their efficacy remains correlational rather than causal. Disentangling the causal impact of statewide obesity prevention policies, apart from other confounding factors, is critical since it allows us to determine whether the scarce educational and health resources invested in implementing such policies have achieved their intended impact.

My study is the first to investigate the causal impact of a statewide policy intervention to address obesity via schools that was implemented in Arkansas in 2003, known as Act 1220, on adolescent obesogenic behaviors and weight outcomes. Key provisions of Act 1220 required public schools to prohibit vending machines as well as conduct annual body mass index (BMI) screenings for all students.

Using existing secondary data from the Centers for Disease Control’s (CDC) Youth Risk Behavioral Surveillance System (YRBSS), my study employs a quasi-experimental design, known as difference-in-differences, to estimate the causal impact of Act 1220 on adolescent obesogenic behaviors and weight. I compare changes over time in the obesogenic behaviors and weight of adolescents in Arkansas’ public schools prior to and after Act 1220 was implemented to changes in obesogenic behaviors and weight for adolescents in public schools within a set of comparison states over the same pre-post implementation period. I also investigate the impact of the provision requiring all public schools to measure adolescents’ BMI and report it to their parents. Given that 11th graders became exempt from BMI screening requirements, I compare changes over time in the obesogenic behaviors/weight outcomes of 11th graders in Arkansas’ public schools prior to and after the exemption was implemented to changes in obesogenic behaviors/weight outcomes for 10th graders. Finally, my study investigates how Act 1220, as a whole, and its BMI notification provision in particular, have impacted the obesogenic behaviors and weight of adolescents from different racial and ethnic backgrounds. My study fills a critical void in our understanding of the efficacy of wide scale school-based policies to address obesity and extends our knowledge of whether the enormous potential that public school systems have to help solve America’s growing obesity problem among adolescents can, in fact, be realized in practice.