Objective: To identify predictors of becoming eating disordered among adolescents.
Design: Prospective cohort study.
Setting: Self-report questionnaires.
Subjects: Girls (n = 6916) and boys (n = 5618), aged 9 to 15 years at baseline, in the ongoing Growing Up Today Study (GUTS). Main Exposures Parent, peer, and media influences.
Main outcome measures: Onset of starting to binge eat or purge (ie, vomiting or using laxatives) at least weekly.
Results: During 7 years of follow-up, 4.3% of female subjects and 2.3% of male subjects (hereafter referred to as "females" and "males") started to binge eat and 5.3% of females and 0.8% of males started to purge to control their weight. Few participants started to both binge eat and purge. Rates and risk factors varied by sex and age group (<14 vs > or =14 years). Females younger than 14 years whose mothers had a history of an eating disorder were nearly 3 times more likely than their peers to start purging at least weekly (odds ratio, 2.8; 95% confidence interval, 1.3-5.9); however, maternal history of an eating disorder was unrelated to risk of starting to binge eat or purge in older adolescent females. Frequent dieting and trying to look like persons in the media were independent predictors of binge eating in females of all ages. In males, negative comments about weight by fathers was predictive of starting to binge at least weekly.
Conclusions: Risk factors for the development of binge eating and purging differ by sex and by age group in females. Maternal history of an eating disorder is a risk factor only in younger adolescent females.