Dave Hargreaves Personal Training

IIFYM, Flexible Dieting & Personal Training at Doherty's Gym, Brunswick

Dave Hargreaves Personal Training

IIFYM, Flexible Dieting & Personal Training at Doherty's Gym, Brunswick

Criticism of the BMI

Criticism of the BMI

So… when I’m not in the gym I spend too much time on various social networking platforms talking health, fitness, training, weight loss, etc. Something that’s been kind of irritating me a bit lately on these websites is the trend of bashing the BMI and disregarding it as a measure of healthy weight ranges.

Take it from a qualified professional trainer (and body composition specialist, at that) who is technically 10kg overweight…

the BMI is actually a very useful tool. Like anything in life though, it has its limitations. In otherwords, it is useful in providing a GUIDELINE or you might say “ballpark figure” of what we can consider healthy or unhealthy weight ranges, but requires that you also apply some basic common sense or intelligence when interpreting the results.

First off… you need to understand how unhelpful this is. Seriously.

The worst is in cases where for example some young girl comes to me for advice, and this happens;

Girl: I need you to help me lose 5kg.
Me: Absolutely not. You’re already at a low BMI, losing any more weight would be dangerous and unhealthy.
Girl: Oh I don’t believe in the BMI. I saw a video on the internet where they said it was wrong. Anyway, I’m fat. Are you going to help me or not?
Me: You don’t need to lose weight. Just hit the gym and work on improving body composition while maintaining your current weight.
Girl: No I’ll just stop eating.
Me: *bangs head against desk*


Also, how about this one?

Adult female: Can you help me with a program to tone up my stomach and the back of my arms?
Me: Ok… well according to the BMI you are only about 5kg overweight, so we will dial in a nutrition plan to support the healthy weight range for your height and….
Adult female: Overweight? How dare you! I’m not overweight – the BMI is flawed anyway. I’m perfectly healthy.
Me: Why is this my life?

This has actually happened to me a few times as well. ┬áSo, the issue is not just about overweight people thinking they’re not overweight (even though they’ve just asked me for a weight loss program?!)… the bigger concern to me is the people who refuse / are unable to accept that they are underweight and under eating.

The BMI is the only tool we’ve got, and subject to some common sense and intelligence it’s a pretty good one. Unless you’ve come up with something better, stop spreading this garbage misinformation that enables unhealthy / at risk people to disregard it.


Most of the criticisms I keep reading and hearing about the BMI are actually quite ironic and illogical. People might read my paragraph earlier where I say “it’s just a guideline and you need to apply common sense when interpreting the results”, and respond with “so you admit it is a flawed system? It should be done away with!” But at the same time, the most common complaint I see about the Body Mass Index is “it assumes there is just one healthy weight that all people should be”.

Do you get my point? They can’t have it both ways. You can’t complain that the system expects all people to weigh the same, and then complain that the system isn’t accurate enough as well. This whole “it doesn’t take different body types and amount of muscle into account and thinks there is just one healthy weight that all people should be” is actually a total fallacy that I’m about to bust wide open right now.

Lets look at MY stats:

Age: *mumble* 38
Height: 168cm
Weight at lowest BMI in the “normal” range: about 57
Weight at highest BMI in the “normal” range: about 70

Notice anything? There’s a 13kg difference between the highest and lowest weight of the “normal” range for my height and age. That’s a MASSIVE variance! How can people say it doesn’t account for different body types or body compositions?

Next myth I’m going to bust; “here’s a picture of a bodybuilder, technically he is obese; therefore the BMI is junk and we should throw it out”. Well… remember what I said about COMMON SENSE? I don’t really look like a body builder, but I’d fit into that category of people who are above their “normal” weight range due to busting their arse to put on some extra muscle in the gym. It’s common sense that there’s a difference between being technically overweight as an athelete with relatively low body fat and lots of muscle mass, and being actually overweight (over fat).

We can consider the waist to hip ratio to determine if someone with a higher BMI is just built larger while still being relatively lean, but in most cases common sense should be sufficient. If you’re just slightly above the normal BMI, maybe it’s because you are packing some extra muscle. If you’re WAY above and carrying a spare tyre around the waist… is there really anything to argue about here?

You need to address this. It is a HEALTH issue.



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