Originally Posted by
krazygluon
The only credibility I would give this is that I do generally believe, its not so much the fat, but the inactivity that makes fat people unhealthy. That said, I agree that BMI is ****e and that I too get dubious results on my electronic scale. (I keep getting only 56ish %water...I thought human body was 70+% by nature? No way I'm that dehydrated on a constant basis)
BMI was developed by insurance companies to allow easy rate setting off simple morbidity tables. A morbidity table is a table that states the risk a person is going to die during the term of the policy. Such tables use a number of factors, age, marital status, sex, smoking and BMI among them. BMI is a simple calculation that states for a certain height you should be in a certain weight range. It does not account for muscle mass, so a person who is very muscular would have a high BMI, but could still have a healthy body fat percentage.
Electronic scales are not accurate for water percentage calculations, they work with averages as well.