**6. Body weight as per the recommended body mass index (BMI) for the respective populations**

The WHO 1998 Consultation on Obesity, based on classifications used in a number of past studies on Europids, indicated BMI of 18.5–24.9 kg/m<sup>2</sup> as normal [34, 35]. A WHO expert consultation on BMI for Asian populations concluded that Asians generally have a higher percentage of body fat than white people of the same age, sex and BMI and that the proportion of Asian people with a high risk of diabetes and CVD is substantial at BMIs lower than the existing WHO 1998 cut-off point for overweight (>24.9 kg/m<sup>2</sup> ) [36]. The WHO [35], International Diabetes Federation and American Diabetes Association have recommended the upper limit of cut-off point of normal BMI for Asian people as 22.9 kg/m<sup>2</sup> [25, 35, 37]. Similar and variables recommendations for different non-Caucasian populations have been made in various other studies, including those conducted in the Westernized ones.

These recommendations are in agreement with the actual body mass index of the population. The adult mean BMI levels of 20–23 kg/m<sup>2</sup> are found among the general population in Africa and Asia, whereas levels of 25–27 kg/m2 across North America and Europe in 2002 [10]. The WHO consultation on BMI for Asian populations identified further potential public health action points along the continuum of BMI and indicated that the earlier optimum population range (21–23 kg/m2 ) gives some intuitive consistency for policy makers [36]. The risk of insulin resistance and diabetes in adult increases progressively upwards of a BMI of 20–22 kg/m<sup>2</sup> [10]. More than 80% of the people with diabetes live in low- and middle-income countries and nearly two thirds of diabetes globally are attributable to BMI above 21 kg/m<sup>2</sup> [10]. In general, the risk of insulin resistance and glucose intolerance appears to increase once BMI starts rising above the middle of the recommended BMI for the population.

**Research perspectives:** Compared with the BMI cut point of 30.0 kg/m<sup>2</sup> among Europeans, a similar glucose factor distribution is observed at corresponding BMI cut points of 21.0 kg/m<sup>2</sup> in South Asians, 20.6 kg/m2 in Chinese and 21.8 kg/m2 in Aboriginals in Canada [38]. The BMI cut points are, however, higher, for the lipid and blood pressure factors than for the glucose factor in South Asians, Chinese, and Aboriginals in the study [38] pointing out the need to study BMI cut points in different populations similarly considering the glucose, lipid and blood pressure factors separately.
