So true. The BMI is a simple metric for tracking general trends in body composition of populations over time. It is a statistical tool. It was never intended to say anything about individuals.
You can thank insurance companies for popularizing this over-simplified statistical tool. Any excuse to raise an individuals rates.
But as a statistical tool it is probably being applied correctly in this study. We are becoming a nation of fat bodies who can't do anything. I would guess that far more than half people collecting disabilities can have their difficulties directly traced to their weight.
Nearly everyone I have seen at supermarkets lately wheeling around in motorized carts are morbidly obese with only about 5% of the people missing a leg or something or in their 90s and beyond who are not fat. The same applies to those using 95% of the handicapped spots.
This was designed to define millions of healthy people as unhealthy solely based on height and weight and not providing any other context. It is the one of the worst things this country has done to mess up people.