h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

BMI has formed the basis of defining abnormal weight for more than 100 years. Howevere, it would appear that this definition of obesity may have to be revised as researchers from the Mayo Clinic, Oochester, Minnesota have found that heart patients defined as being 'overweight' according to BMI, actually survived longer than those judged to have normal weight. They found that seriously obese patients had a higher risk of heart-related death - but 'overweight' patients had better survival and fewer heart problems than those with normal BMI..In turn, those with normal BMI were less likely to die than those with low BMI.
The better outcomes for overweight patientswere most likely due to muscle, which weighs more than fat, according to a report in The Lancet (18/08/06)Thus BMI is related to, but is not an absolute measure of abdominal fat. The moost important thing to consider is body shape and weight. Eating less and being more active is an effective way of controlling both , and improving your heart health. i.e. Waist to hip ratio was the most reliable predictor of heart attack risk. As a rough guide, doctors regard a waist circumference of over 40 inches for a man and 35 for a woman as danger signs.
Consider Jonah Lomu - NZ rugby star. He has a BMI of 32, yet could hardly be described as obese.

"Consider Jonah Lomu - NZ rugby star. He has a BMI of 32 , yet could hardly be described as obese"

Certainly not to his face

What about the Inuit and the extinct Tierra del Fuegans who were all murdered in their beds? They're not / were not obese. It's just / was insulation.

More obese people since the advent of central heating I think you'll find. "Pass me the crisps, Dora ....