Helpful or harmful? Prospective association between weight misperception and weight gain among overweight and obese adolescents and young adults.

BACKGROUND/
OBJECTIVE: Weight misperception is common among adolescents with obesity, but it is not known whether weight perception is related to future weight gain. The objective of the study was to examine the prospective association between accurate weight perception versus weight misperception and weight change among youth who are overweight or obese. SUBJECTS/
METHODS: Using a subsample of The National Longitudinal Study of Adolescent to Adult Health Wave II cohort, we used linear regression modeling (adjusted for age, baseline body mass index (BMI), parental education, household percent federal poverty level, depression, race and ethnicity) to examine the prospective association between weight misperception (that is, perceiving oneself to be under or normal weight) among 2738 overweight and obese youth and subsequent BMI change from Wave II (1996) to Wave IV (2008-2009). Mean age at baseline (Wave II) was 15.9 (0.1).
RESULTS: Fifty-seven percent of males and 80% of females accurately perceived themselves as overweight. In fully adjusted models, weight misperception was associated with less BMI gain among youth who were overweight and obese. Specifically, youth who perceived themselves to be at a healthy weight had lower BMI gains (males: β= -1.43, 95% confidence interval (CI)=(-2.26, -0.60), P=0.001; females: β= -1.35, 95% CI=(-2.59, -0.11), P=0.035) from Wave II to IV relative to those who accurately perceived themselves as overweight or obese.
CONCLUSIONS: Contrary to commonly held assumptions, weight misperception among a non-clinical sample of youth who were overweight or obese predicted lower future weight gain. Efficacy of efforts to correct weight misperception should be rigorously examined to assess for both intended and unintended consequences.