apparently,30% of western adults are regarded as clinically obese,quite a frightening statistic.
Not necessarily a "frightening statistic".
BMI should be used as a guideline only as a measure of height:weight, because it doesn't account for is what makes up that "weight". Unfortunately in this day and age, BMI is pretty much the only measure that is used when reporting modern obesity.
AFAIK, the BMI categories were conceived in the late 1940's. The problem with that, of course, is that most people in the 1940's (esp. in europe) were malnourished, having grown up during the depression and then WW2.
Today people are taller and larger than they were, and have far more muscle mass than when the BMI categories were written. It's common for body builders to be classified as obese.
My 2c
DIVOSH!