It may be that doctors do not treat thin patients as aggressively as they do heavier patients — or that the yardstick itself is to blame. Most researchers assess obesity by measuring body mass index, a simple ratio of height and weight. But B.M.I. does not take into account body fat, lean muscle mass, metabolic abnormalities and other nuances of physical composition.
Perhaps, some experts say, we are not asking the right question in the first place. Maybe we are so used to framing health issues in terms of obesity that we are overlooking other potential causes of disease.
- More Data Suggests Fitness Matters More Than Weight, The New York Times