Based on a research on aborigines in solitary parts of Australia suggest that the healthy limit on body mass index might be lower than previously thought. The body mass index (BMI) is calculated by dividing your mass in kilograms by your height in metres, squared. Till now a BMI between 20-25 was considered to be the healthy range, while 25 to 30 is overweight, and over 30, obese. Health risks increase with BMI over 25. But a survey of 2,500 aborigines living in remote areas of Australia suggest that those with BMI in the 20 to 25 range might also be at risk of glucose intolerance and diabetes.
Overall, 15 per cent of the group had impaired glucose tolerance, and 14.5 per cent had diabetes. People with BMIs of 22 or more had three times the risk of developing impaired glucose tolerance, and four times the risk of diabetes. The researchers calculated that if they could prevent gains in BMI beyond 22, then 46 per cent of diabetes cases could be averted and 30 per cent of cases of impaired glucose tolerance. This only applies to aborigines - previous research has shown that certain ethnic groups are more vulnerable to the health risks of weight gain.