Risk Factors for Adopting Extreme Weight-Control Behaviors among Public School Adolescents in Salvador, Brazil: A Case-Control Study.

Objective: This study identifies the risk factors for extreme weight-control behaviors among adolescents in public school in Salvador, northeastern Brazil.

Methods: A case-control study nested to a cross-sectional study, including 252 adolescents of both sexes, age between 11 to 17 years, with 84 cases and 168 age-matched controls was conducted. The variable outcome is represented by extreme weight-control behaviors, integrated by following the variables: self-induced vomiting and the use of laxatives, diuretics, or diet pills. Covariables included body image dissatisfaction, dieting, prolonged fasting, and self-perception of body weight. The study also investigated the demographic and anthropometric variables and economic conditions of the students' families. Conditional logistic regression was used to identify risk factors for the adoption of extreme weight-control behaviors among adolescents.

Results: Among the adolescents investigated, the conditional logistic regression explained 22% the occurrence of extreme weight-control behaviors and showed that these behaviors were positively associated to overweight (odds ratio [OR] = 3.61; 95% confidence interval [CI], 1.42-9.17), body image dissatisfaction (OR = 3.87; 95% CI, 1.75-8.54), and the adoption of a restrictive diet (OR = 2.83; 95% CI, 1.16-6.91).

Conclusions: The results of this study suggest that among adolescents, overweight, body image dissatisfaction, and restrictive diet are important risk factors to adoption of extreme weight-control behaviors.