At my place of employment every year we have a ‘health screening’ where one gets weighed, blood pressure/sugar checked etc.; you would not believe some of the people who get a referral for being obese; it is ridiculous. Now I’m not saying there are not a lot of fat people out there, there are; but to classify someone who is 5’10” & 210 lbs. on a large frame is foolish; that person is not even fat, much less ‘obese’...not sure what is behind this, except maybe just another government power grab, but they really need to check the classifications.
The BMI calculation is biased by height. My 17 year old niece is 5'10", thin, very athletic (on varsity soccer team), and yet the BMI indicates she is 'obese'.
Go look at the chart again. On the left are Japan, South Korea, where there are a lot of short pudgy people, but because of the BMI formula's height bias they are not considered obese. Meanwhile, countries with tall people are all mostly on the right, where the BMI is biased upward.
The chart is biased in favor of short people because of the way the BMI formula is not properly calibrated for height. I'm not saying the US doesn't have an obesity problem (it does), but BMI isn't a good metric the way it is currently defined.