Dieting status and its relationship to eating and physical activity behaviors in a representative sample of US adolescents.

OBJECTIVE: To determine whether adolescents engaging in extreme weight loss methods (i.e., vomiting and diet pills) and those using more moderate methods differ from each other in dietary intake (fruits, vegetables, and higher-fat foods) and physical activity, and to compare these variables in dieting and nondieting adolescents.

DESIGN: Data were obtained from the 1993 Youth Risk Behavior Survey.

SUBJECTS/SETTINGS: The survey was administered to a nationally representative sample of 16,296 adolescents in grades 9 through 12 in a school setting.

STATISTICAL ANALYSES: Data were analyzed for 16,125 adolescents. Associations between weight control behaviors and dietary intake and physical activity were examined using mixed-model logistic regressions, controlling for grade in school, race, parental education, region of the country, and urban vs nonurban residence.

RESULTS: Differences in dietary and physical activity were found among adolescents who use extreme weight loss methods and moderate methods, and between dieters and nondieters. Adolescents using moderate methods of weight control engaged in more health-promoting eating and exercise behaviors than did extreme dieters or nondieters. Girls categorized as extreme dieters were less likely to eat fruits and vegetables than were moderate dieters (odds ratio [OR] = .56) or nondieters (OR = .75), and were more likely than more moderate dieters (OR = .76) to have consumed 2 or more servings of high-fat foods during the previous day.

APPLICATIONS/CONCLUSIONS: Our findings suggest the importance of distinguishing between different types of dieting behaviors in clinical settings and research studies. Adolescents engaging in extreme weight control behaviors may be at particular risk for inadequate nutritional intake. In contrast, adolescents using more moderate methods may be consuming a more healthful diet than are nondieters. For all adolescents, nutrition guidance on healthful and safe weight control strategies is needed.