Weight-control behaviors among adolescent girls and boys: implications for dietary intake.

OBJECTIVE: To examine associations between healthful and unhealthful weight-control behaviors and dietary intake among adolescents.

DESIGN: Cross-sectional survey (Project EAT [Eating Among Teens]).Subjects/Setting The study population included 4144 middle and high school students from Minneapolis/St. Paul public schools from diverse racial and socioeconomic backgrounds. Statistical analyses Dietary intake patterns were compared across adolescent girls and boys reporting unhealthful, only healthful, or no weight-control behaviors in unadjusted analyses and analyses adjusted for sociodemographic factors and energy intake.

RESULTS: Among girls, mean intakes differed across weight-control behaviors for all foods and nutrients examined. P values ranged from P=.006 to P<.001. Girls using unhealthful weight-control behaviors had significantly lower intakes of fruit; vegetables; grains; calcium; iron; vitamins A, C, and B-6; folate; and zinc than girls using only healthful weight-control behaviors. Compared with girls reporting no weight-control behaviors, girls using unhealthful weight-control behaviors had lower intakes of grains, calcium, iron, vitamin B-6, folate, and zinc. In contrast to the girls, boys reporting unhealthful weight-control behaviors did not have poorer dietary intakes than boys not using weight-control behaviors or using only healthful behaviors. Among boys, there were no significant differences in mean intakes of vegetables; grains; calcium; iron; vitamins A, C, and B-6; folate; and zinc. Furthermore, boys using unhealthful weight-control behaviors had higher fruit intakes (P=.002) than boys reporting no weight-control behaviors.

CONCLUSIONS: Adolescent girls who engage in unhealthful weight-control behaviors are at increased risk for dietary inadequacy. The findings demonstrate a need for interventions to prevent unhealthful weight-control behaviors in adolescent girls, and to promote healthful weight-control behaviors when indicated.