some interesting numbers

[lnr]

Currently I weigh somewhere in the region of 17 stone (108 kg) and I'm about 5'6" (1.68 m) which makes me 38.3 BMI, my clever scales say I'm somewhere between 47 and 50% fat, I'm female and I'm 30.

Guidelines say that people should be between 20 and 25 BMI, and women my age should have between 21 and 33% bodyfat. So by BMI I should be between 8 stone 12 (56.5 kg) and 11 stone 1 (70.5 kg). At my thinnest I was just under that upper limit.

Let's assume that I'm at the higher of those two fat percentages. That means I currently have 50% lean mass (8 stone 7, 54kg). If I lose only fat, then 21% bodyfat would be at 10 stone 11 (68.5 kg, 24.3 BMI) and 33% bodyfat would be at 12 stone 10 (80.5 kg, 28.5 BMI). 20 BMI would leave me with only 4.5% bodyfat.

Of course you *don't* lose only fat when losing weight, and that still leaves me needed to lose over 4 stone to be in a healthy range, but it's definitely food for thought.

Comments

[furrfu.livejournal.com]

I've always been very suspicious about those boundaries - 20 and 25 are suspiciously rounded to me, and when I see numbers like that I immediately assume a fairly big error margin. Esp. since at least one reputable study (of which I can't find the URL just now) found that people with a BMI between 25 and 30 actually lived longer, on average, than those between 20 and 25. Not by much, but longer...

[lnr]

So we aim for around the 25 mark and don't worry too much? *grin*

[innocencest.livejournal.com]

The 'healthy' range varies by age and gender, but it still doesn't take into account general body shape. 20-25 is a very approximate average.

My BMI is 19, but I'm still just within the healthy range.

[lnr]

That fat percentage isn't fixed either, they reckon 15-20% fat is OK for female athletes for example...

[chickenfeet2003.livejournal.com]

I'm a bit on the porky side too at the moment but the BMI stats still look odd.

I'm a little over six feet tall, weigh 225#, have a body fat % of 29 and a BMI of 30.5. That computes to a lean weight of 160#.

If I dropped to 160# I'd still have a BMI of 21.7 and zero fat.

I probably ought to be around 195#. I know that's the weight I was when I was super fit and playing serious rugby. But by BMI that would still make me quite noticeably overweight.

[catyak]

BMI is a flawed measure anyway. To increase in proportion, you'd expect weight to go up as the cube of the height, not the square. Tall people need to be wider or they'll break. I have similar numbers to you at the moment. When I was younger I was indeed closer to 160lb and suffered several occurrences of collapsed lungs which were attributed to being too thin.

So yes, it's a useless measure invented by the medical people to beat us with, knowing they can blame all ills on us not meeting their numbers.

D

[damerell.livejournal.com]

Cube - no. Tall people _aren't_ proportioned precisely like short people. But square's no good either, indeed.

[uisgebeatha.livejournal.com]

The BMI is notoriously bad as a measurement of healthy weight, as it doesn't take things like muscle mass into account. For instance, it would claim that the entire England rugby team is obese!

I remember going to get weighed at the docs in sixth year, and at the time I was 10 and a half stone. The BMI chart in the surgery put me- wait for it!- in the 'fat' category. Not slightly overweight, 'fat'. If that's not enough to prompt an eating disorder I don't know what is! o.O

Every person is different, but I'd say 10 stone is a pretty healthy figure to aim for. If it's any consolation, I've gone from 11 stone down to 9 stone since I started my MSc (I'm about 5'3), and I actually preferred it when I was a bit curvier- being thinner means more sticky-out bony bits and clothes that don't fit anymore. ;)

[lnr]

It was partly the fact that it was so completely out compared to the fat ranges that rather surprised me.

It's always said it's wrong for people with lots of muscle because they're very athletic, but I wouldn't have put me in that sort of category!

[tlingel.livejournal.com]

At the beginning of 2003 I was 15st 1LB (I am the same height as you. When I had my stroke I was 13st 2LB(June 5th just past. Now I am 10st 11LB (BMI of 25 very-ish. Not a good method of losing weight though-lying in a hospital bed. Got lots of exercise while the physio was teaching me to walk again. The weight I lost properly I did by cutting out cheese and chocolate (mostly) for 2 years or so. It wasn't fun, and I started sliding back up several times.Shame my blood pressure was still through the roof at the end.

[bugshaw.livejournal.com]

Do you know if your body fat measurement is percentage of weight or volume? That could have some bearing.

[tlingel.livejournal.com]

Sorry, no idea what it is officially, although I suspect it's weight.

[damerell.livejournal.com]

You don't only lose fat when losing weight, but losing muscle isn't much use (ie, really you'd want to exercise to grow it back, modulo the fact that losing weight improves power/weight ratio a bit, so it wouldn't ultimately be a net saving) and losing, ah, certain other tissue won't be appreciated by your fanclub. :-)

[new-brunette.livejournal.com]

I don't think BMI's a bad tool, just one which shouldn't be applied blindly.

Just because atheletes and rugby players don't fit it doesn't mean that it's not a useful guide. If you're overweight and you're trying to get a feel for where you need to get to, if you get down to below 25 you've eliminated the extra health threats caused by being overweight. And for most people, their ideal weight from a health POV will be somewhere between 20 and 25.

In your case, it's probably at the 25-end of that range; certainly that was true for me. My lowest, at BMI 24, left me with a bit of a paunch but quite a haggard face and 20 would have been ridiculous. Even so, I'd be surprised if you did get down to 20 whether your body fat would be as low as that for the reasons you describe.

There's evidence to show that 30+ and 35+ are both significant points in terms of exposure to risk. Like you, I'm someone who got down there and am now back over 35, and I'm in no doubt that I need to turn it around again.

*le fucking sigh*

[lemur-catta.livejournal.com]

Apparently BMI standard allows for 85lbs lean body weight on a woman of my height (4'11") but body composition testing showed it to be more like 93lbs and that was before I started doing circus so it might be even higher.

[deborah_c]

Hmm. I think I have a healthy distrust for BMI. I waver between around 70kg or 75kg, depending on how neurotic I've been about eating (and how much chocolate I've laid my hands on) and I'm 5'9. The upper end of that is a BMI of 24.4, and even at that weight, I'm still quite thin.

Three years ago, I got very depressed, more or less didn't eat for four months, and went down to just over ten stone; I looked almost skeletal and had friends seriously worried about my health, with a BMI of 21.5. I don't think I'd like to get down to the lower end of the range you mention...

[bopeepsheep.livejournal.com]

You and I are pretty much the same shape (and height). My GP wants me to be somewhere around 12st. She says hang BMI, it's how one feels and looks at a weight that matters, and at 8st12 I look dreadful (I have been this weight, she's right). My collarbones stick out. At 11st I look and feel good, but aiming for 12 is more realistic...

[simont]

In the pub this evening it occurred to me that it'd be funny if posts of this type were under an lj-cut with the cut text "( BMI )" :-)

[reddragdiva]

BMI should be referred to as often as possible as "Bullshite Marketing Index."