AIBU to tell you that BMI doesn't apply to everyone!

[Randomuser456]

Foreword I know it's a blunt tool, etc, etc ,etc... and I DO exercise more than the average person (don't really ift heavy) but I've always thought my clothes size doesn't match my weight.

Anywho according to the Navy Body Fat formula I'm around 27-28%

A BMI extrapolation would put me at 38%. By reversing that calculation someone with my BF% is around 15kg lighter than my current weight.

Anyway just a public service announcement :)

5"2, 10st 2.
I was stretching, to see if I'd gained any muscle mass rather than to look thinner.

@Mylegishangingoff I agree I don’t think it’s particularly common in females to have this body type.

Thank you for the compliments, i appreciate it!

I'll clarify i didn't use this post to invite compliment! 🙂more so to stress that many women who look something like me, may be classed as overweight by a BMI scale as am I at 5'2 and just over 10st. I think it is worth considering as a subject.

I'm going to ask MN to take my post down because my name change didn't work 🤣🤣
But I'll leave it up for a bit because I think this is important. And this post is interesting. Maybe I have a heavier frame. I don't have large hips but I have large hands and broad shoulders.

@TheBunnyLover you look amazing and sort of physique I am aiming for

It really depends where you carry your weight. Mine is mostly in my arms (which is why it takes a lot of work to show any definition even though my dumbbells are 15kg and I can do 8 bicep reps with them).

The trouble with BMI is it doesn't take into account body types, and where people store the weight. A larger waist and tummy is health wise far more of an issue than fat hips and thighs. Some people are mesomorphs, they are an athletic body type, muscle weighs more than fat. A shot putter has an entirely different body type to a sumo wrestler or a ballet dancer.

I think my pleasing American Navy result was down to all of my flab being on my thighs

There's another one (can't remember the name) that asks for calves and thoughts measurements too

@BobnLenthis is where weight is so bizarre. I’m 5’10”, a size 12-14 and I weigh 13st 4. I lift heavy weights and do have a lot of muscle, but it’s crazy the variance. I could do with losing a stone but then look very slim at that weight

NO thank you! 😂

How is it really misleading? The point is that a smaller (in volume) but more muscular physique can often weigh more than a flabby larger physique. Nobody is saying anything about converting muscle into fat (or I’m not anyway) but the BMI chart makes no distinction between a muscular person with a small waist and a person who has a lot of excess fat. Thats why you get some threads where someone is 11 stone and a size 16 and someone else is 11 stone and a size 10 (both same height). I find the distinction made between volume for fat and muscle very helpful.

Muscle is heavier than fat in that it’s denser. If you have two people that are both a size 14 and one of them doesn’t do any exercise and the other lifts weights 5x a week, chances are the muscle mass for the person who lifts weights is going to make them heavier than the other person, and the BMI result will be skewed because it doesn’t take into account body fat percentage.

Which is why a healthy BMI is such a broad range. It isn't "skewed".

But if you’re getting told you’re overweight but are perfectly healthy / have lots of muscle then that’s when I think the numbers get skewed. It’s misinformation at that point. I do think that BMI is vastly under or overweight categories are broadly correct however.

Most people who are told they are overweight, are actually overweight. If you are genuinely so athletic that you are one of the few outliers, it will be so obvious and you will be so tuned in that you would pay BMI no notice. The bigger issue is fat people trying to convince themselves that they are not fat because XYZ athlete is also "overweight".

^ this. It was only after I went to a clinical/sports dietitian that she said that losing weight was not going to make any difference beyond aesthetics.

On the same token she said more training would not benefit my health any further, but then it would be a matter of performance.

You can’t just say muscle weighs more than fat, it needs exactly that context about the density. The statement without context is what is misleading. The majority of women do not realise how little muscle mass they have without a lot of effort and what it takes to build and maintain it and even then it’s not very much. This thread is a good example, women assuming they have a lot of muscle from what may be low level activities causing their BMI to be skewed and higher than it ought to be but it’s quite unlikely to be correct. It’s unusual and unlikely for a woman to be muscular enough to give a high BMI reading unless they are an athlete. If you look at the female gladiators they are an example where this would be true but for most other women it isn’t

These women I would assume certainly do not fit the BMI correctly due to muscle mass. This is what I would assume those women would look like visually for it to be obvious.

FYI I think they look amazing and I could never even dream of getting a physique like this I can only imagine what hard work it is

Same, but I’m a 14-16 when I’m between 15-17 stone
it takes about 3 stone for me to lose a dress size

Your title says BMI but you don’t mention BMI anywhere in your OP. So why are you targeting BMI? Your issue seems to be inaccurate body fat calculations.

In any case, at 28% body fat you’re certainly not fit or above average in any way. If you did exercise more than average, you would have better than average stats. 28% body fat is something you should be aiming to reduce. If you had more muscle, your body fat would be lower. It’s that simple. Have you actually measured your body fat properly ie with callipers or with a proper machine?

The people who tend to criticise BMI act like it’s not accurate for 50% of the population. In reality the people who BMI isn’t accurate for is likely closer to 10%. You certainly wouldn’t have enough muscle to throw BMI calculations off, as it’s the extreme ends of the scale where BMI is not helpful such as very short/tall or bodybuilders. Not people like you, OP who have an average/overweight physique.

Exactly. It is humorous that OP thinks they have a lot of muscle mass!

BMI is a blunt tool. But it broadly works for adults outside of outliers.

My BMI is 30. So I am in the Obese category. This is, objectively, bad. Sadly, I know it's actually WORSE. I have the bones of a bird. I won't be doign the fat calculation because I know it will be terrible. I am desperate to start on the injections.

DH is the complete opposite. He measures his fat on one of those fancy machine sbecause he's very fit and does it as a job. He has the fat level of a high level athlete. His BMI says he's very overweight. It's complete bollocks.

As for using it for children.... that infuriates me becuase there are way MORE outliers.

In year 6, when they measured DS, they had him as obese. He was 95th percentile for height and 90% percentile for weight. He was tall and very slim. When I typed his EXACT measurements into the NHS calculator but added two years to his age.... he came up as a perfect BMI. He will be like his father (and uncle, and grandfather and who else on that side of the family tree - heavy boned.

Sorry, to clarify, our family are the outliers I mentioned above. Ironically, on both sides. Me with an artifically "low" BMI and DS/DH with an artificially high one.

Tbf I think it would be pretty unusual for someone who works out so much that they have so much muscle that pushes their bmi well into the overweight category to need someone to tell their body is made up muscle not fat.

Exactly. It would be bloody obvious.