Does that mark me perverse?
As Keith Devlin has pointed out:
“The BMI was formulated, by a mathematician, not a medical physician, to provide a simple, easy-to-apply mathematical formula to give a broad, society-level measure of weight issues. It has absolutely no scientific or medical basis. It is based purely on a crude statistical analysis. It measures a general society trend, it does not predict. Since the majority of people today (and in Quetelet’s time) lead fairly sedentary lives, and are not particularly active, the formula tacitly assumes low muscle mass and high relative fat content. It applies moderately well when applied to such people because it was formulated by focusing on them! Duh!
“But this is not science - it’s not even good statistics - and as a result it should not be accepted medical practice, to be regularly flouted as some magical mumbo jumbo and used as a basis for giving advice to patients. (For heavens sake, even seven times Tour de France winner Lance Armstrong’s own Livestrong website provides a BMI calculator, despite the fact that the boss himself, when he first became a world champion cyclist - before chemotherapy for cancer took 20lbs off him - found himself classified as “overweight” by the wretched formula.)”
So you need to spare the angst , Steve — I go with waist measurement.
The same blog entry quotes a study, that suggests much greater leeway in regard to “healthy”:
“a study of 33,000 American adults, published recently in the American Journal of Public Health (Vol 96, No.1, January 2006, 173-178), showed that male life expectancy is greatest for BMIs of about 26 - overweight under the CDC’s rule, and equivalent to 24 lb extra for the typical man. For women, the study found an optimum BMI of about 23.5, about 7 lbs heavier than the CDC’s standard.”
So while BMI may be broad scale suggestive — of one wanted to be a enforced statistic — it aint a rule.]]>
For older Americans, over 65, the longest lifespans are seen at BMI between 25 and 30.
For a quick and dirty assessment of potential lifespan and cardiovascular risk, the waist-hip ratio may beat BMI. Here’s my post about WHR: