COLUMBIA U. (US) — Despite lots of criticism, body mass index is still the best way to determine who’s obese and therefore at risk for a host of health problems, say researchers.In recent years, a chorus of voices has expressed doubts about BMI, weight divided by height squared. The measure doesn’t distinguish fat mass from lean mass, they say. A bodybuilder and someone with a beer gut can have the same BMI. And, it doesn’t account for the location of fat tissue: abdominal fat expands your risk of heart disease and diabetes more than fat elsewhere.