Body image distortion and three types of weight loss behaviors among nonoverweight girls in the United States.

PURPOSE: To examine the relationship between body image distortion (BID) and onset of three types of weight loss behavior among nonoverweight girls in the United States.

METHODS

Data were from the National Longitudinal Study of Adolescent Health (Add Health) (n = 20,745) and included 5,173 nonoverweight (body mass index [BMI] < 85th percentile) adolescent females aged 11-19 years who completed Wave I and II interviews. Actual and perceived weight statuses were compared to assess BID. Logistic regression was used to predict onset of three types of weight loss behaviors at Wave II from BID at Wave I, adjusting for Wave I weight loss behaviors and demographics.

RESULTS

At Wave I, 85% of nonoverweight girls engaged in weight control behaviors, and 29% displayed BID (i.e., overestimation of weight status). When compared to girls without BID, those with BID at Wave I had 4.3 times greater odds of onset of extreme weight loss behavior (e.g., vomiting, laxatives, diet pills) (OR = 4.5, CI = 2.44-7.42) and 2.3 times higher odds of onset of dieting to control weight (OR = 2.30, CI = 1.72-3.06) 1 year later. Girls who practiced extreme weight loss had 10.7 times greater odds of continuing unsafe practices 1 year later than girls who did not (OR = 10.67, CI = 4.27-26.63). BID was unrelated to exercise for weight control.

CONCLUSIONS

BID predicts onset of unsafe, but not safe, weight loss behavior among nonoverweight girls. Brief assessment of BID may help identify nonoverweight girls at risk for unsafe weight loss practices and strengthen prevention efforts.