ABSTRACT ASSOCIATION BETWEEN SEDENTARY BEHAVIORS AND BMI IN US ADOLESCENTS: ANALYSIS OF THE 2015 YOUTH RISK BEHAVIOR SURVEY By SARAH SADRUDDIN KABANI April 27, 2017 INTRODUCTION: Research has shown a strong link between sedentary behaviors and obesity among adolescents. AIM: This study aims: 1) To determine sedentary behaviors in US high school adolescent nationally 2) To determine the association between sedentary behaviors and BMI after controlling for demographics, recreational behaviors, diet, and physical activity 3) To examine the association between engaging in more than one sedentary behavior and BMI after controlling for demographics, recreational behaviors, diet, and physical activity METHODS: The Youth Risk Behavioral Survey (YRBS) 2015 data was utilized in this study by using weighted percentages to determine the association between sedentary behaviors and BMI while controlling for demographics such as age, sex, race, and grade, recreational behaviors such as smoking and alcohol consumption, diet such as fruit, vegetable, and soda consumption, and physical activity. Univariate logistic regressions and multivariate logistic regressions were conducted to determine the association between sedentary behaviors and BMI. Adjusted and unadjusted odds ratio, 95% confidence intervals, and p-values were calculated. RESULTS: 81.6% of adolescents watched TV during a school day, while 18.4% did not watch TV during a school day. For video games/computer usage/social media (PG) usage, 82.6% engaged in PG usage during a school day, while 17.4% did not engage in PG usage during a school day. When stratifying by BMI, overweight adolescents and obese adolescents have significantly different sex distribution (p=<0.0001), race/ethnicity distribution (p=0.047), TV usage during a school day (p=0.04), PG usage during a school day (p=0.047), and TV & PG usage during a school day (p=<0.02). For TV & PG usage during the school days, adolescents who watch TV and PG, were at higher odds of being obese [AOR =1.3 (1.04, 1.6), p = 0.02] when comparing to adolescents who did not watch TV and PG. DISCUSSION: This study concludes that there is an association between obesity and adolescents who watch TV and use video games/computer/social media during a school day. Sociodemographic factors such as some races, age, and gender are also responsible for obesity among adolescents.