The expression BMI gets thrown out a lot lately, but it seems to me that very few people — either health professionals talking about weight, or people who talk about the fact that skinny is a lousy metric of health understand very well.
BMI means Body Mass Index. It’s a height/weight ratio. That’s it. It doesn’t measure what the weight is composed of (muscle, bone, adipose tissue, water bloating or anything). It’s just what you get when you step on a scale. Most adult male athletes would be considered overweight or obese by BMI standards. Clearly this is a measurement that leaves much to be desired.
It was developed somewhere between 1830 and 1850 by Adolphe Quetelet, a Belgian scientist who was trying to develop a discipline known as Social Physics. This was basically the study of Man by means of statistical measurements. Because many of his theories were not well thought of by his peers, the discipline of sociology supplanted it not long afterwards.
Quetelet did work in the public health sector, where his formula of BMI was applied to issues of health of the day. Thing is, these measurements were used to establish an average based on the 1840-1850 set of measurements he took. “Average” was then taken as a baseline for “acceptably healthy”.
Friends, barring cancer, almost anyone reading this is far healthier than the average person of the 19th century. Our mothers were better nourished while we were gestating. Our medical care — even if it was sub-standard, was better than was even available then. Losing a child has gone from something routine that most mothers faced to something unusual and unexpected. I have a friend who’d be facing death in childbirth in the next few weeks if it weren’t for obstetrical advances.
I wanna chuck the BMI for one reason: It’s bad science. It’s a statistical measurement based on environmental conditions that no longer exist compared to conditions we no longer find desirable. We’ve got better ways to measure health now. Let’s use ’em.