Validity of body mass index in determining prevalence of overweight and obesity among Syrian late adolescents boys

• The prevalence of overweight and obesity for Syrian adolescents was determined.
• The appropriate cut-off points of the body mass index (BMI) were calculated.
• The prevalence of overweight and obesity was 24.5% by BMI.
• Whereas, the prevalence of overweight and obesity was 46.5% by body fat content.
• BMI cut-off points were 22.34 kg/m2 for overweight and 24.71 kg/m2 for obesity.

Obesity is rising among adults and children worldwide, including populations living in developing countries. The published data related to Syria are insufficient to address this issue. Therefore, the aim of this study is to determine the prevalence of overweight and obesity, and to determine appropriate cut-off points of the body mass index (BMI) for defining overweight and obesity among Syrian adolescents. We record body weight (kg), height (m2), and body mass index (kg/m2). The total body fat mass (BFM) was determined by deuterium oxide dilution (DD). The total sample was used in a split-sample internal cross-validation. The BMI was integrated to multiple regressions and Bland and Altman's procedure was used to analyze the data. Receiver operating characteristics (ROC) curve was drawn to determine appropriate cut-off points of the BMI for defining overweight and obesity. The prevalence of overweight and obesity was 24.5% by BMI and 46.5% by body fat content. Receiver operating characteristics (ROC) curve analysis defined a BMI of 22.34 kg/m2 as a cut-off for overweight with sensitivity of 84.0%, 80.9% specificity, and BMI of 24.71 kg/m2 with 82.80% sensitivity and 93.0% specificity for obesity. The results of our study suggest lower BMI cut-offs for overweight and obesity in Syrian population than those of recommended by WHO.