Which normal range of Body Mass Index be used for Indian adults?
There are two different sets of recommendations for designating adults in the normal range for Body Mass Index, i.e., 18.5 to 24.99 and 18.5 to 22.99 by World Health Organization. Some scientists are advocating that in case of Asians the normal range for Body Mass Index should be from 18.5 to 22.99. Which one to follow?
Presently I am engaged in the population based family history analysis of type 2 diabetes in a particular community. I have little experience in this field but what I have observed is this that present cut off values of BMI are based on western studies and they are not applicable commonly to all Indians. In India lot of variations are found among different caste groups and those again vary according to the geographical distribution in this country. As per the prevalent standard values of BMI (Mostly determined by western scholars) , I have found very very few cases of T2DM. instead , I found more cases of T2DM in the BMI range of greater than 18.5 and lesser than 25 which indicate Normal BMI ! It is necessary to take up larger study of the Indian Population for setting standards of BMI . Present studies are not large enough to draw any conclusion if one sees the population size of India with varied castes and religion and geographical distribution and life styles.
It is understandable that different populations may have differential susceptibilities and health risks for similar ranges of body-mass index (BMI) just as other morphological and physiological parameters do. A WHO specialist group investigated the issue for redefining the BMI ranges. The findings were published in Lancet (Lancet 2004; 363: 157–63) which indicated that the risk of type 2 diabetes and heart disease is substantially higher in case of Asians than the Europeans at the existing WHO cut-offs of BMI. WHO expert consultation committee didn’t recommend the redefining of the existing cut-offs, however, they concluded that BMI values of 23, 27.5 and 37.5 should be monitored for potential health actions.