> What interests me is how anybody could ever come to believe otherwise. The contrary belief flies in the face of all common sense, popular experience and medical science.
Did you read the article?
I can give you two simple examples:
Look at any picture of Dwayne “The Rock” Johnson when he has been ripped. Ditto with Arnold Schwarzenegger in his prime.
BMI says these folks are either obese or severely obese. Extreme examples, but illustrative of the weakness of bmi.
On a personal level, I have been listed as obese by a doctor when I weighed in 205 as someone who is 5’11” (somewhat carelessly, because bmi was 28.x, and “obese” is 30+, but still…).
Doctor did not care to notice that I was very muscular, exercise regularly (weights and cardio), and was pretty lean.
The doctor wanted to talk to me about my “weight problem”. I pulled out dexa can showing that I had 176 pounds of lean body mass and was 14-15% body fat (“healthy” range, and probably much leaner than her, even though she was slight build and thin), told her about my diet and exercise regimen, and she quickly reversed course.
You can see how muscular people are unhappy about bmi being used for individual evaluation.
BMI is a measure that is meant to be used to measure populations rather than individuals. Being used as a quick a dirty evaluation tool without looking in more detail by the doctor is irresponsible medicine — yet it is common practice.
This is why “anybody could come to believe otherwise”.
Obviously, if the dexa scan comes back saying someone is 30% body fat, no amount of muscle can make that “healthy”, but I think that’s not where most thoughtful people have issues with potentially specious claims of obesity.