
If you’ve just calculated your BMI and are wondering if this BMI is accurate, then you’ve landed in the right place. If you’re a fellow Fitness Professional and still use BMI with your clients, then you’ve also landed in the right place. In fact, this information needs to be read by… well, everyone.
Recently, in a women’s cycling community on Facebook, the topic of cycling and weight loss came up… again. Someone in the thread suggested the poster hire a Personal Trainer for nutrition advice and how she should use BMI as an indicator as it “is appropriate for >90% of people”.
I couldn’t scroll past, because, as a Personal Trainer, I know that we are not qualified to dish out nutritional advice and I’m pretty aware how irrelevant and discriminatory BMI usage is. So I commented and said just that, only to be told that she “is a medical doctor and both my statements are incorrect”. Apparently “BMI is an accurate measure of your weight status unless you’re a weight lifter or body builder”.
So either I’m overweight, or I’m a weight lifter or body builder.
I was gobsmacked to be honest. Not only could someone be so naive but they felt comfortable throwing around the fact that they work in medicine. Which is quite frankly, frightening. Anyway, I figured I’d let someone else from the community who knows more about this topic than me share why it’s time to ditch BMI. Let’s hear from Leah…
This is a GUEST BLOG?!?! How exciting, thanks Elle!
I solemnly swear not to… swear, and I’ll be EXTRA polite and take my shoes off at the Blog Based Door! Promise!
I’m Leah from Backing my Body. Personal Trainer, Occupational Therapist, Eating Disorder Specialist and co-founder of workEDout campaign.
I’m passionate (for so many reasons) about raising awareness of Eating Disorders, challenging diet culture, and making the fitness space a safer one for ALL.
It’s one of my favourite spaces, yet we have work to do to make it one which welcomes, accepts and takes care of every single one of us, whoever we are, whatever we look like, and howEVER our bodies want to move.

Something which has contributed to exclusions from many spaces and opportunities across a whole host of industries is the Body Mass Index (BMI).
The BMI debate – is BMI accurate?
If I said the BMI isn’t relevant for 90% of the population would you believe me?
I could *try* and write a neutral view of it. Present both sides of the ‘argument’ as to why we should/shouldn’t use it. But I’m not going to, because I can’t. I’ll leave that for someone else (and good luck to them!).
I can’t because I strongly believe the BMI should NOT be utilised as a measurement of health.
At all. End of.
But let me tell you why, with a real life story.
The origins of BMI
200 years ago, in the 1830s a Belgian man named Adolphe Quetelet walked this very Earth. His specialism was in identifying the characteristics of the ‘average man’ (hang on a sec, can you even IMAGINE that this was a SPECIALISM LOL, I wonder what GCSEs he took for that one).
Anyway, he believed that the mathematical ‘mean’ of a population was its ‘ideal’. He graphed the ‘ideal’ height and weight of French and Scottish men into a bell curve and the BMI was born.
Here’s a quiz:
Are you a man?
Yes? No?
Are you French?
Yes? No?
Are you a man?
Yes? No?
Are you Scottish?
Yes? No?
Are you a unique, individual, ONE OF A KIND human being bringing your own personal mark, thoughts, feelings, image and experience to this brilliantly diverse world?
Yes.
Then bin the BMI.
None of us are born to seek and mould ourselves to meet an unattainable ‘ideal’. How can we be?
We are each our own ideals.

Quetelet had NO medical background. Not only that, he was a co-founder of positive criminology and phrenology, both schools of thought rooted in racism.
From the onset he provided us with an un-scientific formula based on the size and measurements of white, western Europeans.
By the turn of the next century, the BMI was used as a scientific justification for Eugenics – the systemic sterilisation of people of colour, people with disabilities, those with autism and immigrants.
This BLAAADY useless Manly Invention was used to justify scientific racism for decades.
It lay low for a few years before being revived in the 20th Century by none other than insurance companies. They used it (in their favour) to decide how much to charge policyholders, yet, weight and height were self-reported, and the majority of the population couldn’t afford insurance anyway…! Again…pointless!
“My main problem with BMI is that it’s outdated; alongside the fact it’s inconsiderate of people’s lifestyle, race and possible underlying health issues. When we live in a world where we have access to so much new technology and studies, I find it utterly baffling that we continue to use this system. I’ll never forget my health check with a well-known life Insurance Company, and being told I was “overweight” on the BMI scale (by 1lb, I kid you not). I left feeling frustrated and misunderstood, but I dread to think of the impact on other people when eating disorders in so many different forms are on the rise.”
Katie, Cakes vs Scales
A later study (on just 7,500 white men) in the 1970’s concluded that the BMI was the strongest of 3 weak measures, and therefore it should be used. (You can’t make this sh*t up!!)
If the BMI hadn’t been useless in its life so far, it certainly was now.
Weak in its conception, weakened further as each decade has passed.
Why we should ditch BMI
Ok. Let’s sum up.
The BMI has always been based on a tiny fraction of people YET dangerously applied to everyone.
It’s controlled us, dictated our consumerism, devalued our worth, and given 90% of us unattainable ‘targets’ which many have punished themselves in an attempt to meet. It’s led to misdiagnosis and mistreatment for many, especially marginalised members of our society.
I still can’t believe (and it slightly scares me?!) that it’s survived this far.

The BMI overestimated weight and health risks for Black People and People of Colour.
The BMI underestimates health risks for Asian communities.
The BMI suggests OVER significant sex-based differences in the relationship between body fat and BMI.
Its very existence suggests that EVERYONE ‘should’ be expected to adhere to a ‘white standard’.

I try not to get angry, but it’s hard. So much of what we do, how we live our lives, and the systems they are built on are based on… “well that’s just how it’s always been…that’s just how it is”.
When it comes to measuring health using the Body Mass Index giving such reasoning will NEVER be good enough. This is our LIVES.
Personally, the BMI controlled my very existence in a nearly decade long fight against Anorexia. Mine is one story but there are many.
I won’t stop fighting until we’re free of it.
Leah
If this is a topic you would like to explore more, here are some resources recommended by Leila of Inspire.
- Health at every size by Linda Bacon, this study goes into depth about BMI and how inaccurate it is.
- I would also recommend Train Happy by Tally Rye a qualified personal trainer.
- And Pretty Unhealthy by Dr Nikki Stamp.
- Another advocate is Dr Joshua Wolrich on Instagram
Couldn’t agree more!
Great post, ladies!
Thank yooooou! And keep up the good work you’ve been doing with Leah and WorkEDout x