Re-evaluation of WHO-defined BMI cutoff value for defining overweight and obesity in the Bengalee (Indian) population

Abstract

Body mass index (BMI) is the most useful epidemiological measure of obesity. However, there is increasing evidence suggesting that World Health Organization (WHO)-proposed BMI cutoff points for overweight and obesity cannot be readily applied to the Asian population. Thus, the purpose of this study was to establish appropriate cutoff points of BMI for defining overweight and obesity based on body fat percentage (BF%) of the Bengalee (Indian) population. The study was conducted on 654 subjects (18–60 years), of which 336 were men and 318 were women. The subjects were selected from different parts of the state of West Bengal, India. Anthropometric measures and blood pressure were obtained using standard techniques. The BMI and BF% were calculated using the standard equation. Receiver operating characteristics (ROC) analysis was done to determine the appropriate cutoff points of BMI for overweight and obesity while taking BF% as the standard. Based on BMI, 12.50 % of men and 13.84 % of women were overweight and 1.79 % of men and 1.89 % of women were obese. On the basis of WHO gold standard, 18.75 % of men and 14.47 % of women were overweight and 9.82 % of men and 9.43 % of women were obese. ROC curve analysis showed a low sensitivity and high specificity of conventional cutoff points of BMI for identifying overweight and obesity. A lower cutoff value of BMI 21.87 kg/m² for overweight and BMI 24.33 kg/m² for obesity displayed good sensitivity and specificity, and an optimum area under the curve. We suggest a BMI of 21.87 and 24.33 kg/m² as the optimum cutoff points to define overweight and obesity, respectively, for the Bengalee population.