The performance of obesity screening tools among young Thai adults.

Obesity is a worldwide medical condition that leads to physical and psychological impairment. Specific ethnicity, gender and age group are related to different performances of anthropometric indices to predict obesity. The objectives of this study were to estimate the performance of the anthropometric indices for detecting obesity based on percentage of body fat (PBF), to study the correlation among those indices, and to determine the optimal cut-off point of the indices among young Thai adults. This is a cross-sectional study of healthy urban subjects in Khon Kaen, Thailand who were aged 20-39 years. Baseline characteristics and anthropometric measures were collected. PBF was determined using bioelectrical impedance analysis. Demographic data and anthropometric variables were analyzed using descriptive statistics. Receiver-operating characteristic (ROC) curves were used to compare the performance of anthropometric measures as predictors of obesity. One-hundred men and 100 women were recruited for this study. Body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-stature ratio (WSR) were significantly correlated to PBF. BMI demonstrated the best performance according to the area under the ROC curves in both sexes at cut-off points of 22.5 in women or 25 kg/m(2) in men. WC and WSR showed better performance than WHR to detect obesity. In conclusion, anthropometric indices in young Thai adults were correlated well with PBF to predict obesity as shown in prior reports. Different cut-off points of these indices to define obesity in young Thai adults are recommended. The global cut-off points of WSR in women regardless of ethnicity are supported.