Mombu 2010-07-04 10:47:17
This link, off the url you poosted, clarifies the issues you raise.
The ranges of “normal” etc. are so broad as to take into account gender
and other such normal differences. The case of body builders etc. is
different in that they are indeed on the tail of the bell curve of the
populations, they are abnormal in that regard. Fitness and body fat don’t
equate. I n the old days of soviet olympic teams their power lifters had
great bellies but most likely could not be faulted for fitness. Fitness
and body weight are only indirectly related. For purposes of population
based research the bmi does a very good job as an independent variable
and/or must be normalized with other variables to isolate the item one is
trying to isolate in the research question. It describes the great bulk
of folk who in the real world reside in the hump of the bell curve, not
the abnormal situations of fashion models, body builders, etc. whose
numbrs are so small as to mean nothing.