Abstract EP16: High Area Level Public Transportation Associated With Increased Body Mass Index In High School And Male Adolescents

Overweight and obesity rates increased dramatically among United States youth from 1999-2016, particularly among adolescents. Promoting physical activity can reduce youth obesity rates, particularly among overweight adolescents, most of whom do not meet guidelines for at least 60 minutes of daily physical activity. Neighborhood public transportation usage is an important environmental factor that has potential to impact adolescent physical activity. We examined the association between neighborhood public transportation usage and adolescent body mass index (BMI) drawing from the Family Life, Activity, Sun, Health, and Eating (FLASHE) study, a cross-sectional national survey conducted in 2014 that assessed cancer preventative behaviors, including physical activity and diet, among adolescents (aged 12-17 years, n=1,737) and their parents. We used linear regression models to test the moderating effects of age, sex, and socioeconomic status and the mediating effect of physical activity on the association between neighborhood public transportation usage and adolescent BMI. The analytic sample included 357 adolescents of middle school (44%) and high school (56%) ages evenly distributed by sex (51% female) with 39% of the sample below 200% of the Federal Poverty Line. On average, adolescents had a BMI percent of the 95 th percentile of 81.77 (17.09) or 22.24 (4.67) BMI and self-reported 71 daily (out-of-school) moderate-to-vigorous activity minutes. While we found no overall association between neighborhood public transportation usage and BMI, we found that low neighborhood public transportation is associated with increased BMI among high school (14% (95% CI 5.72, 21.41)) and male (7.16 (95% CI -13.41, -0.91)) adolescents respectively. We also found that physical activity does not mediate the effect of neighborhood public transportation usage on adolescent BMI. Our findings suggest that our adult reported public transportation measure could be pointing to neighborhood factors, such as poverty or crime, that affect the association between neighborhood public transit and adolescent BMI. Our findings help inform future research on the dynamic relationships between individual and social environmental factors that impact adolescent physical activity.