Interesting history of body mass index (BMI) measurement
The BMI calculation was created by a Belgian mathematician — not a doctor or health practitioner.
In the 1830s, Lambert Adolphe Jacques Quetelet set out not to devise a test to quickly diagnose obesity (which was still years away from being widely perceived as a problem), but to find the ‘l’homme moyen’ or the ‘average man’.
His thinking went that you could take thousands of measurements, compare them, and find the ideal weight. Through calculating these samples he found that weight typically increases in relation to the square height of a person.
But there were big limitations to Quetelet’s experiment. For one, all the participants were western European men. The experiment also had nothing to do with measuring individual health.
Lambert Adolphe Jacques Quetelet created what later became the BMI in his quest to find the ‘average man’. (Wikimedia: Library of Congress)
It wasn’t until the 1970s when American physiologist and dietician Ancel Keys and a group of his colleagues promoted Quetelet’s Index as the best available way to quickly screen for obesity that it became what we know today as the BMI.
But like Quetelet, the Keys study didn’t account for all body types. It only measured 7,426 ‘healthy’ men from 12 sample groups.
They included American students and professionals, Italian railway workers, men from east and west Finland, Japanese farmers and fishermen, and Bantu men from South Africa (which the study itself says “could not be suggested to be a representative sample … of Bantu men in general”!)
So why is it still used?
Because it is simple and no one has come up with a better one.
And, with about two in three people in the UK classified as either overweight or obese (according to BMI), we need a way of describing this important health issue.
Experts say this has been exacerbated by the pandemic, with lockdowns and the push towards working from home leading to more sedentary lifestyles across the population.
