Abstract 12 Adolescent Medicine II Platform, Monday, 5/3

Obesity among teens has been associated with gender and socioeconomic status (SES). How teens and their parent(s) view their weight status compared to objective anthropomorphic measures is unknown. This study determines (1)differences in teen and parental report of obesity, (2)amount of misclassification using body mass index (BMI) from self report (SR) vs. measured height and weight as an indicator of obesity, and (3) whether misclassification varies by gender and SES. Design: Data from 15,932 baseline (T1) youth and parental interviews from the National Longitudinal Study of Adolescent Health were used. 78 % of teens were re-interviewed one year later (T2). Parents reported parental education (PEd), household income(HI), and if their teen was obese. Teens reported height (Ht), weight (Wt), and Wt perception. Those endorsing the "very overweight" category on the 5 point Wt perception scale were considered obese by SR. BMI was calculated from both SR Ht and Wt at T1 and T2 and from measured Ht and Wt and T2. Those with a BMI ≥ 95% corrected for age and gender were considered obese. Results: At T1, 7.2% were obese by BMI, 6.5% obese per parent report, and 3.5% obese by SR. Almost half (47%) of teens reporting they were "very overweight" were not obese by BMI. For teens obese by BMI, 20% were reported to be obese by both parent and teen, 6% by teen only, 45% by parent only, and 44% by neither teen nor parent. At T2, the correlation between BMI calculated from SR vs measured Ht and Wt was very strong (r=0.92, p<0.0005). SES indicators were not significantly linearly associated with differences in SR vs. measured Ht, Wt, or BMI, although HI was associated in nonlinear fashion with differences in Wt (p=0.006). Gender did not affect reporting of Ht. Girls under-reported Wt and had lower SR BMI than boys (p<0.0005). However, girls were no more likely than boys to be misclassified as obese using SR BMI. Overall, 3% of teens were misclassified using SR measures. Lower age (P<0.001), lower PEd (p=0.046), and lower HI (p=0.02), but not race, were associated with misclassification. Among those misclassified, 70% were misclassified as non-obese and 30% as obese. Gender, race, and PEd were not associated with type of misclassification, but lower HI was (p=0.01). None of the 578 teens with persistent obesity (obese at T1 and T2 by SR and at T2 by measured BMI) were misclassified. At T1, teen and/or parental report failed to identify more than one-third (34%) of those with persistent obesity. 23% were identified by both teen and parent, 5% by teen report only, and 37% by parent report only. Conclusions: Parental report is a better indicator of obesity than teen report of wt status, but parental and teen reports are both poor predictors of adolescent obesity. Using BMI based on self reported Ht and Wt correctly classified 97% as to obesity status. Thus, studies can use SR Ht and Wt to understand teen obesity and its correlates/sequelae.