Wanted

-- Although obesity is today a global pandemic, research on the disease in India is still nascent. This worries experts: nearly 15-30 per cent of the country's urban population and four to eight per cent of the rural population is either overweight or obese, with children forming 16-18 per cent in this group. It is a rising trend, experts say; the rate at which urban Indians are turning overweight or obese already equals that found in Western European cities. An added concern is the parameters by which an Indian -- indeed an Asian -- can be declared overweight or obese.

Twenty years ago, researchers in Europe and the us defined the normal limits of bmi, or body mass index, a measure of obesity. (Expressed in kilogramme per metre square, kg/m², it is the ratio of a person's weight and height that takes into consideration the total composition of fat, muscle, bone and tissues in the human body.) Surveying around 80,000 Caucasians, researchers correlated the bmi of each person to mortality rates. This led to the first-ever definition of obesity: those with bmi between 25-29.9 kg/m² were classified as overweight and those with bmi above 30 kg/m² were classified obese. The International Task Force on Obesity and the World Health Organization (who) accepts these limits -- they are now universally applicable. But these limits are precisely what researchers in Asia are today questioning. They are based on the Caucasian body. How can they be applicable to Asians, whose bodies are different?
One such researcher Five to six years ago, Anoop Misra, a professor at the department of internal medicine, All India Institute of Medical Sciences, New Delhi, became intrigued by a phenomenon: obesity is one of the strongest risk factors for diabetes, but Misra noted that whereas diabetics among his patients were on the rise, these very people couldn't be categorised as obese. Misra began researching this puzzling fact. Officially, not more than five to 10 per cent of Indians had a bmi more than 30 kg/m². So how was the leap in diabetes cases to be explained?

Universally, bmi is measured by two rules: body fat as a standard and comparing the bmi against it; and by comparing bmi against diseases. Misra found that, in Indians, at lower bmi the body fat was high. "Suppose at a bmi of 25-26 kg/m², 10 per cent of Caucasians have diabetes, then Indians achieve that 10 per cent at a bmi of 22 kg/m² itself," says Misra. In other words, Indians become classifiable as overweight or obese at a lower bmi. According to him, this warrants the bmi limit for which Indians should be labeled as overweight to be less than 25, thereby redefining the global limit (see table: New definition). "It is not the question of diabetes alone," Misra says.