Body weight perception and illicit drug use among adolescents

Objective: This study tests the relationship between overweight perceptions and use of cannabis and cocaine among adolescents. Study Design: We analyze pooled cross-section data from 2005, 2007 and 2009 waves of the Youth Risk Behavior Survey, a biennial, nationally-representative survey of 9–12 graders in the U.S. Outcomes are dichotomous indicators separated for cannabis and cocaine use. We construct dichotomous indicators for slightly overweight perception and very overweight perception, with normal body weight perception serving as the reference category. To estimate a causal relationship, we estimate multivariate bivariate probit models in which actual weight affects drug use through perception of body weight. Dichotomous indicators for actual weight are constructed based on the age-sex-specific BMI percentile. We also examine subgroups stratified by sex. Estimates are adjusted for the complex survey design of YRBS. Results: As compared to those with normal-weight perception, adolescents with very-overweight perception are more likely to use cocaine by 5 percentage points (p > 0.001). A greater effect is found on the adolescent male subgroup (p > 0.001). Adolescents with a slightly overweight perception are less likely than those with normal weight perception to use cannabis by 3 percentage points (p > 0.001). No gender difference is found for the slightly overweight perception subsample. Conclusions: Overweight perception has a significant impact on cocaine use among adolescents. This effect is larger for adolescent males. This relationship may assist in identifying youths at a greater risk of illicit drug use.