The BMI is BS

BMI has become not only an assessment of size, but has absurdly served as a representation of health, character, morality and social value.

There is so much judgment, shame, and contempt associated with flawed and imperfect BMI values.

BMI has become integrated into the Western medical model, so much so that it is almost universally and unquestioningly accepted as a valid measure of health.

The reality of BMI however, is at best invalid, and at worst, actively harmful.

It was first developed 200 years ago by a Belgian astronomer (Adolphe Quetelet) who believed that taking the mean height and weight of a bunch of French and Scottish men in the military would give the ‘ideal’ measurements for the human man. This work operated within the boom of racist science, and was used to judge fitness for parenting and justify the sterilisation of minority groups.

The original developers of the BMI made it clear it was never intended as a measure of individual body fat, build, or health. He developed it as a way of measuring populations, not individuals, and it was designed for the purposes of statistics, not individual health.

In the early 1900’s, U.S. life insurance companies started to develop tables of their policy holders’ height and weight to guide pricing structure. This was incredibly biased, as it was comprised of largely privileged white males that had access to life insurance, and height and weight were often self-reported and inaccurate. These tables were then picked up by physicians and used to evaluate their patient’s weight and health.

By the early 2000’s, the BMI’s flawed and imperfect measure had become a routine part of doctor visits.  

Cultural views have hardly shifted since then, even though the science has started to. Science has repeatedly demonstrated that the BMI is a measure built by and for white people and does not cater for cultural or gender differences.

The science has disproved many common myths about size, health, and weight loss for years. Yet, instead of recognising the evolving and increasingly complex science around fatness, people stick stubbornly to an idea that allows them to freely marginalise fat people.

The BMI is a product of its social context. And, even according to its biggest champions, is not an effective measure of fatness, much less overall health.

My next blog will explore… if not BMI, then what is an indicator of overall health?