Body Mass Index and Obesity : Tailoring "cut-off" for an Asian Indian Male Population

Obesity/overweight is a recognized risk factor for a host of disorders. The disease risk stratification is commonly based on the Quetelets Index (Body Mass Index- BMI), a surrogate measure of fatness. The currently used BMI cut-offs to classify people as overweight or obese in Armed Forces have been defined in studies on Caucasian populations. However, because of differences in body structure and composition in different ethnic, socioeconomic, cultural and regional groups the correspondence between BMI and body fat content varies between populations. We conducted this pilot study in the Indian Navy to define BMI cut-offs for overweight and obesity using body fat content derived from Skin Fold Thickness as the standard.

The study was conducted on 121 volunteers from a naval hospital staff in the age range of 18 to 47 years. The mean age, height, weight, BMI, body fat in the study group was 26.73 years (± 5.5098), 168.56 cm (± 6.1034), 65.92 Kg (± 10.2746), 23.17 Kg/m(2) (± 3.0265) and 19.91% (± 4.831) respectively.

The prevalence of overweight/obesity was 20.66% by BMI and 47.11% by body fat content. Receiver operating characteristic (ROC) curve analysis defined a BMI of 23.85 kg/m(2) as the cut off for overweight with a sensitivity of 70.2% (95% CI 56.6 - 81.6) and 87.5% specificity (95% CI 76.8-94.4) and a BMI of 24.38 kg/m(2)with 90% sensitivity (95% CI 68.3-98.5) and 81.2% specificity (95% CI 72.2-88.3) for obesity.

The results of our study suggest lower BMI cut offs for overweight and obesity in Indian populations than those recommended by WHO.