Dietary and physical activity factors related to eating disorder symptoms among middle school youth.

BACKGROUND Dietary and physical activity (PA) behaviors can predict disordered weight control behaviors (DWCB) among youth. This study examines dietary and PA correlates of DWCB and differences by race/ethnicity and weight status in a diverse sample of youth. METHODS Self-reported data on dietary weight management behaviors, strengthening/toning exercises, moderate-to-vigorous physical activity, and DWCB (vomiting, taking laxatives, and/or taking diet pills without a prescription) were obtained from 15,260 sixth to eighth graders in 47 middle schools participating in the Massachusetts Healthy Choices Study at baseline (2005). Generalized estimating equations were used to estimate odds of DWCB associated with dietary and PA behaviors and to examine for differences by race/ethnicity and weight status, adjusting for covariates and clustering of individuals within schools. RESULTS Disordered weight control behaviors were reported by 3.6% of girls and 3.1% of boys. Youth who engaged in strengthening/toning exercises 7 days per week versus 0-3 days per week had increased odds of DWCB (girls odds ratio [OR] = 1.9; 95% confidence interval [CI] = 1.3 - 3.0; boys OR = 1.5; 95% CI = 1.0 - 2.2). Dietary weight management behaviors were associated with increased odds of DWCB (girls OR = 1.2; 95% CI = 1.1 - 1.3; boys OR = 1.3; 95% CI = 1.2 - 1.4) for each additional behavior. These associations did not differ by race/ethnicity or weight status. CONCLUSIONS Persons promoting healthy dietary and PA behaviors among youth should consider the co-occurrence of strengthening/toning and dietary weight management behaviors with DWCB and the consistency in these associations across racial/ethnic and weight status groups.