06/29/2022
Great read on the origins of BMI!
When your doctor is evaluating your health, they have a bunch of numbers to look at. Blood pressure. Heart rate. Cholesterol, white and red blood cell counts, and however much cannabis they find in your p**s? They all feel like real measurements of some f**kery flowing through your n**s.
So what in Hippocrates name is BMI and should you give an ounce of f**k?
Today’s Moment of Science… Quetelet’s Index.
Lambert Adolphe Jacques Quetelet was a Belgian astronomer, social scientist, and statistician born in 1796. He graduated with his PhD in math in 1819, setting out to apply the burgeoning field of statistics to goddamn everything from birth to death. In his ‘social physics’, a precursor to sociology, he was out to quantify what it meant to be a person.
And really, how better to understand humans than to turn them into neat, soulless little plots of numbers?
Quetelet suspected that a representative sampling of people could demonstrate the normal distribution of human… everything. In the middle of his bell curves would be “l’homme moyen,” or Quetelet’s average man, what he considered to be the human ideal. Which, uh, doesn’t not sound eugenicky (stick a pin in that).
To be fair to Dr. Quetelet, it wasn’t like he presented his research as “the ideal human is clearly Danny DeVito, everyone else out of the genepool.” His publications pinned numbers on a wide range of phenomena, from how many people get married at which age and gender to the likelihood of a stillbirth in the country vs the city, in one city or the next.
To find the data he used to make Quetelet’s Index, I read two of his dusty publications (one of which was in French, the other was nearly 200 pages long). From all the reading, I can only conclude that Quetelet and his Index were done f**king dirty. Because these were never intended to be health guides.
BMI is calculated by dividing weight (in kilograms) by height (in meters, squared). Which I tried to find as Quetelet’s Index in his book, but instead I found the following quote:
“The stature of men and women, fully developed and well-formed, varied in the proportion of five to six nearly: it is almost the same with the ratios of the weight to the stature of the two sexes; whence it naturally follows, as we have already said above, that the weight is in proportion to the square of the stature.”
Yeah, the ‘weight is in proportion to the square of stature’ bit was the whole precursor for the BMI racket.
Though they pulled height and weight readings from more than enough people for statistically significant data, there were other types of deficiencies. Their range only went up to 6’2’’ and 215lbs, was almost assuredly racially homogeneous, and likely in good shape from doing peasant s**t.
Quetelet admitted, “I have taken care not to include ricketty individuals in these valuations, or badly formed persons, or even those who were round-shouldered, and unable to stand up-right for many minutes.” I’m not clear on what he’s referring to by ‘badly formed persons,’ but it doesn’t sound like he wanted a representative sample of the population after all.
It’s also not too surprising that some of his work in anthropometry was later expanded upon by some of history’s finest eugenicists. His work on the positivist school of criminology was also a tad, uh, skull-measury for my taste.
In 1972, Ancel Keys, a pioneer in nutrition research, rebranded Quetelet’s statistical little nothing into ‘Body Mass Index.’ Keys conducted his own study compiling the heights and weights of over 7,000 men, all in good health, showing that yeah, the ratio held up but nothing much more. The paper even concluded that in their attempt to conjure something other than ‘arbitrary definitions’ of obesity, they made something only “slightly better” than a weight to height ratio. Huh.
So does BMI have s**t to do with your health? Eh.
It was really never designed to, and the way it’s used in the healthcare system is borderline criminal.
Remember, BMI and weight aren’t the same thing. BMI is used by insurance companies to determine if your weight is unhealthy. There are a lot of other, better ways to determine if your weight- whether high or low- is contributing to health issues. It’s f**king absurd that entire medical systems around the world are still using this metric from a Belgian statistician born in the 1700s as an indicator of health that was never goddamn intended for this, and absolutely never designed to include all body types.
No single number can tell you everything about your health, whether it’s BMI, blood pressure, or your cannabis levels. And after reading up on all this, I’m going to chance it on those cannabis levels.
This has been your Moment of Science, still waiting for Danny DeVito to return my calls.
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