An interesting thought about body fat and BMI

[Ianc2]

Is a very fit individual with a BMI of 25 and carrying about about 25% body fat more healthy than a another with a body mass of 29 carrying about 10% body fat?

[Subtle_badger]

No.

The clue is in the word "individual". BMI is a useful metric for populations, but a very poor one for individuals. Yeah, I know, someone should tell the NHS that!

Or Yes

Women are individuals, too, and if the second person is a woman, she is dangerously skinny, probably suffering from amenorrhea and at risk of osteoporosis and other conditions.

[Ianc2 in reply to Subtle_badger]

No easy answers. If it is a young fit male athlete / rugby player with a washboard stomach who bounces when he hits the floor because of his muscle mass. However there are not many people like this..

[Subtle_badger in reply to Ianc2]

I disagree. There are easy answers.

DO NOT EVER APPLY BMI TO ASSESS THE HEALTH OF AN INDIVIDUAL.

[Subtle_badger in reply to Subtle_badger]

Ah! Ianc2 I apologise. My anger with the NHS and the whole concept of BMI, makes me seem to be shouting at you - when all you were trying to do was initiate a conversation. It's particularly ironic (or just annoying) that I got angry at this, because BMI is a pretty good estimate of my healthy weight as I have a pretty average physique.

Please forgive me, and I promise not to be such an arse in the future.

[Ianc2 in reply to Subtle_badger]

Apology not required but accepted. The whole BMI story is a complete can of worms and trying to make sense of it is almost impossible A new assessment method should be called for by an authoritative body using a substantial sample of the population to give a definitive set of guidelines Perhaps it is something the UK Data bank could be used for.

[Subtle_badger in reply to Ianc2]

Thanks lanc2, that is gracious, because I was a bitch!

I had started to believe in Relative Fat Mass, but while that is better, it only estimates percentage body fat. The only health outcome we should be interested in, is visceral fat. I haven't found a simple biomarker for that. Yet.

[MikePollard]

A mirror is the better option.

[Subtle_badger in reply to MikePollard]

I think BMI is a much better measure than the mirror. At least it is objective.

Because two thirds of us are overweight (yeah, that's by BMI 🙄), we no longer have an idea what a healthy body looks like. I have a friend who has rolls of fat around her middle, who has decided she will not pursue further weight loss because she is normal. Well, yes she is, because normal is fat.

(She also tut-tutted my concern at my increasing blood sugar because it's natural for blood sugar to go up as you age. So there's that.)

This is an article illustrating the phenomenon theguardian.com/society/the...

On the other side will be people looking at instagram influencers, or even thinspiration sites, and they will think those people are normal, and feel fat when they are not.

Telling women strip off, and stand in front of the mirror and examine their bodies critically to find fault and decide if they are fat will lead to depression and self loathing.

And I certainly wouldn't want to rely on doctors to judge bodies. My GP doesn't know what obesity looks like - he told me I was fine when he plugged the wrong values into the BMI calculator though I was standing in front of him with my 90cm+ waist. More generally, I am imagining women with male GPs feeling they are exposed to the male gaze, making the doctor's office an unsafe place. And female GPs might be no better: "skinny bitch" or "she's not in a position to judge my weight". BMI or waist is a number, appearance is a criticism.

Maybe it's OK for men; maybe they are psychologically stronger. I doubt it.

I would rather stick with BMI - probably no worse at misdiagnosis, but much less harmful.

(oh, this subject seems to make me prickly!)

[ShrubRose]

My strong view is that it’s not a competition. I feel a bit oppressed at the mo by all the Californian low carb ‘experts’ on Twitter posting pics up with their tops off showing rippling muscles. We don’t actually all have to look like gym wear models. If we don’t feel controlled by food or hunger, all our health indicators (not weight but blood pressure and so on) are fine, our tummies are flattish, that’s fine. We’re fine. People from different ethnic backgrounds are going to naturally have different body composition. I am a tall athletic Caucasian women & I will lose any body ‘competition’ with a slim woman from south east Asia. My BMI will be much higher and so probably will my fat percentage be. But I don’t care. What matters is that I am the best version of me. (Here endeth the lesson)