When it comes to your health and your weight, you know where you are with numbers. It’s all there in black and white, no room for ambiguity. Take waist size. I know my waist measurement so, in theory, I should be able to enter a shop, select a pair of jeans and leave the premises adequately re-trousered in five minutes flat. Except it’s not quite so simple. In Gap I’m a 36″ waist, in Marks and Spencer I’m a 38″, and at Urban Outfitters they won’t let me in because I’m older than eleven. But BMI is different. It’s a scientific equation like E=MC squared so it’s bound to give you an unerringly accurate picture of your weight and state of health, isn’t it? Well, no. In fact, you’d struggle to find a scientist who did think it was a useful metric for individuals but, unfortunately, some huge organisations are still using it in their recruitment practices – and it’s time that stopped.
Part of the issue is that BMI was never really meant to apply to individuals, but to entire populations. It was developed in 1832 by a Belgian mathematician, Adolphe Quetelet, as part of his efforts to define the “average man”. We’ll give you a minute while you go and add Adolphe to your list of famous Belgians. Quetelet noted that “the weight increases as the square of the height”, but he had no interest in using this to define whether people were obese or underweight.
These refinements weren’t added until the 1980s. It was initially seen as a useful formula for actuaries to estimate expected life spans but has gradually become a widely used diagnostic tool. The problems inherent in this were recently pointed out by Nick Trefethen, Professor of Numerical Analysis at Oxford, in a letter to The Economist. He wrote that BMI was a bizarre way for the NHS to measure obesity, and it had resulted in a lot of short people thinking they’re thinner they are while a lot of tall people thought themselves fatter they really are. He suggested some changes to the formula behind BMI, the reaction showed that further problems still exist.
BMI is an imperfect index and you can tinker about with the power of height as much as you like but [the equation] shouldn’t be expected to do what it can’t do which is to measure fatness, because it doesn’t include fatness. Tim Cole – Professor of Medical Statistics At UCL.
Many commentators have been quick to point out that BMI is purely a measure of weight and doesn’t distinguish between muscle and fat. There’s the well-known irony that Brad Pitt, Jonny Wilkinson or Arnold Schwarzenegger can be considered obese purely in terms of BMI measurement. But this overlooks the fact that most of us are in no way comparable to Brad, or Jonny or Arnie. We tend to be a bit more average. For instance, my BMI is 27.7 and I’m overweight. That’s because of the big roll of fat settled comfortably around my waist rather than the rippling, toned mass of muscle which make The Terminator’s numbers look laughable. That’s not always the case though:
I’m about 5’10” and I was once over seventeen stone. I got my weight down to eleven and a half stone and I only just crossed the line from “overweight” to “normal” according to BMI, despite the fact that I could have used my rib cage for a xylophone at that point. Currently, I do intense physical exercise five or six sessions a week and I live on air and protein bars, yet I’m borderline “overweight” according to BMI. WTF, as the young folks say. Amazing Loser – Vince Millett
Another criticism is that BMI doesn’t take fat distribution into account, and body shape is a very important factor in determining health risks. If you have a deposit of fat round your midriff that’s a lot more dangerous than if the fat is lower down. Basically, Kim Kardashian is probably healthier than me, even if we had the same BMI. In essence, BMI needs to be supplemented with a waist circumference measurement to give a clearer picture of overall health – and that’s really not hard to do.
An additional issue is that BMI doesn’t reflect lifestyle changes or overall fitness. If I start an exercise programme and eat a properly balanced diet it will improve my health and give me an increased life span but it won’t necessarily shift many pounds. The improvement in my health will have little or no effect on my BMI and not seeing the dial change at all might well discourage me from making any further improvements. So not only is BMI often inaccurate for men, it also has the added disadvantage of demotivating people from increasing their activity levels.
One of the key issues around BMI from a MAN v FAT point of view is that the use of it as a metric is inherently sexist and discriminatory. Men are more likely to have a higher muscle mass and be taller than women – both of which increase the chances of them registering as overweight or obese on the BMI scale. All of this is relatively old hat and has been discussed and fussed over plenty of times, but the burning issue is that BMI is still blithely used in recruitment practices for some really big organisations, despite being patently unfit for the task. As a result it is negatively impacting on men’s lives.
I lost out because of BMI years ago. I was 21, 6’3″ tall and 17 stone. I was fit as a butcher’s dog – ran six miles every day and regular two hour gym sessions kept me fit. I applied to join the Met Police but I was instantly rejected because of my BMI which was 29.7 – simple as that. I lodged an appeal and was told that they screen candidates on their BMI. I asked about why BMI was used when any international rugby players would have been unable to join and was told that was irrelevant, they screened purely on BMI.
Interestingly, I went to my doctor and spoke to him with the idea of getting a health report to submit – he advised that because of my BMI I was classed as borderline obese as well! How I would love to be 17 stone now! He reckoned I should be around the 11-12 stone mark, oh and he charged me £50 for the privilege of telling me this! The report, when it arrived, was a joke – it focused on my weight. I just thought that 11-12 stone weight “target” was, and still is, unattainable for me.
The experience did make me very depressed, I’d put in months of dedicated effort and hard work for nothing, not even a chance to prove myself, because of a number. I cut back my physical activity and quit running. I just didn’t have that purpose in my life, and I was demotivated. I do believe that is my “sliding doors” moment in my life. WizWas, MAN v FAT forum.
What we need to do
Any number of scientists will give you evidence to say that there are wholesale errors in using BMI to discuss an individual’s weight. They will also show how it is often men who are affected by this to a greater extent.
We can’t let this continue.
It’s not right or fair that companies and organisations continue to use BMI as a measurement in recruitment. We are not questioning an organisation’s right to measure if someone is fit for the job, but we believe that they should be using a more sophisticated metric which is fit for purpose – such as Body Adiposity Index (BAI) or the ABSI index, or BMI with body fat – all of which are freely available.
To change this situation we are asking you to turn whistleblower – if you know of a company who uses BMI in their recruitment process then please let us know and we’ll contact them to ask them to adopt our voluntary MAN v FAT pledge, quite simply this is where they promise to look at their use of BMI and consider whether it’s discriminatory. They also pledge to investigate other weight and fat metrics and release a statement to say whether they’re changing their practices and if not – why not. We’ll report their responses, or lack of them, on MAN v FAT.