Why Body Mass Index (BMI) is an inaccurate indicator of health.

TW- mention of eating disorders.

I would like to start this post by clarifying that these are all my own views, and that I have thin privilege so cannot directly comment on my own struggles with this issue.

Adolphe Quetelet invented the body mass index in the early 19th century, it was only based on white men (specifically Scottish and French) and it is important to note that Quetelet was not a doctor. This from the outset was not designed as an indicator of weight or health, so it should not be used now for this purpose.

Since the BMI has been around for so long the numbers that determine whether an individual is at a healthy weight or not should have remained the same. However, in 1988 the national institute of health changed the overweight BMI from 27.4 to 25, in order to make it more memorable. This essentially means that millions of people became overweight without there BMI changing.

BMI shouldn’t be used as an indicator of health; doctors and the medical system are already fatphobic and the medical system often prescribes weight loss for conditions that do not require it. People can be healthy, or unhealthy at any weight and there needs to be an acceptance of this and a rejection of medical treatment based on weight.

Furthermore, BMI links closely to the treatment of eating disorders in the UK, before people are offered treatment to help eating disorders their BMI has to be recorded and they’ll only be offered help if it is servery under the underweight BMI or highly over. This means that people may be greatly struggling, but because their BMI is not deemed at risk, they are not offered help. Anorexia has the highest mortality of all mental illnesses, but this could be prevented if BMI was not used to measure how worthy people are to get help.

There are other ways to determine health, and even other ways to record weight, because peoples BMI results will vary on ethnicity, upbringing, gender, age and height so it simply doesn’t work for the society we live in now, and its purpose should not be used in way that it was never designed for.