Why are Indians at higher risk of diabetes at lower body weight?

South Asians tend to develop insulin resistance at a lower BMI than European populations, associated with a higher proportion of visceral fat and less muscle mass at any given weight — sometimes described as being metabolically obese at normal weight. This is why the BMI and waist thresholds used for Indians are lower: overweight from around 23 rather than 25, and waist thresholds around 90cm for men and 80cm for women. Practically, it means you cannot rely on looking slim as reassurance, and it makes muscle-building exercise particularly valuable rather than optional.