The BMI Myth

The Body Mass Index scale has been used as a method for determining someone’s health since the 18th century.

The system works by doing some basic maths with your weight and height, then working out whether or not you’re ‘healthy’ from your body fat percentage. Whilst it may sound like a reasonably sound system it’s actually been disproven by various medical bodies.


What’s the Deal?

The issue with BMI is that it doesn’t take a range of factors into account. It ignores muscle mass, bone density, age, ethnicity, and a ton of other things! Meaning someone can weigh more due to their muscle mass, and be in perfect health yet by the BMI scale they’re overweight.

This isn’t new either, researchers have known about this problem for years. There just hasn’t been any real push for change. Sure someone with a BMI of 25 might be unhealthy, but they also might just have a lot of muscle…it’s pretty much a coin toss at this point.


It’s Not Science

Weight divided by height = healthy or unhealthy! A simple, scientifically sound formula. Nah, its bullshit. The scale was created in the mid 19th ceuntry by  Adolphe Quetelet, a Belgian scholar, and we’ve been using it since. At the time he needed to make a formula to allocate health funding, to do so he needed to figure out the average health of a lot of people.

Whilst making up maths formulas might work that way, determining the health of large groups of people isn’t quite so simple. Quetelet’s formula doesn’t particularly work. You end up with a random number that doesn’t take most of your health factors into account and is put onto a ‘scale’. It’s like dividing the length of your hair by the length of your finger nail…it doesn’t predict your health.

BMI is used as a determining factor for many medical practices and affects the way in which doctors and surgeons give help and medical advice to their patients. Using a disproven system means that doctors are missing opportunities to give actual tailored and helpful advice. The BMI scale isn’t just used by doctors though, it’s used at gyms, and schools, and by government bodies. It’s thoroughly engrained into society and our (apparently incorrect) understanding of health.


The Mental Effects

BMI wasn’t intended to be used for individuals, it was just a tool for getting averages from pretty much entire populations. Now that it’s applications have changed and it’s become a lot more personal, the fact that it’s unscientific it’s starting to cause more issues. For many people trying to lose or gain weight they use BMI as a factor to determine how well they’re doing. Although these people may genuinely be healthy their BMI leads to them thinking otherwise.

The misleading results of the BMI scale can lead people to over-exercising or binging in order to become ‘healthy’. By taking the BMI scale at face value people are presented with a very inacurate picture of their health. Trying to be that ‘perfect’ BMI of 20 can be a trigger factor for many people with eating disorders such as orthorexia or binge eating disorders.


The concept of having an easy scale to measure whether people are healthy or not isn’t bad. What’s bad about BMI is that it literally doesn’t work. There are so many ways in which our technology and medical understanding has advanced in the last few centuries, allowing us to more accurately measure health.

Leave a Comment