Obesity, BMI and stuff

[chickenfeet]

I'm overweight but not by much. I weigh 213 pounds which at just over 6 feet tall gives me a BMI of 28.5. I would like to be 200 pounds (BMI=26.7) which would apparently make me still overweight. Frankly this is nuts. I was 200 pounds when I was playing rugby competitively and was as fit as I've ever been in my life. It's not like I'm unfit now. I've run 25km in the last four days which is more than a lot of people do in a year. What's really scary is that according to the BMI calculation I could be 140 pounds and still be a healthy weight! When I was ill about ten years ago I dropped to 155 pounds and I looked horrible, all skin and bone, and not in the least healthy.

So let's look at this in the context of the "obesity epidemic". It's trivially obvious that the BMI statistic exaggerates obesity among tall people and does the opposite for short people (weight, other things being equal, is proportional to the cube of body weight rather than being linear). It's a fact that in the developed world average height has been increasing for at least a hundred years. This of course means that obesity statistics based on BMI will get worse even if nothing is happening! I'm not saying there isn't a problem but it is being exaggerated by the use of a very dubious statistic.

Comments

[itchyfidget.livejournal.com]

Interesting point.

I think BMI is a blunt instrument, but it's a step up from the "one size fits all" height/weight charts we used to get, on which I was always overweight.

[thidwick.livejournal.com]

You're in exactly the same boat as my husband -- he's 6'1", has a muscular build, is a runner, and weighs about 220. He's got some weight to lose, as we're both showing the effects of not-so-healthy eating, but if he gets much below 200 he starts to look unhealthy. But all the "experts" would tell him that he should be down to around 180 to be in the normal/healthy weight range. Bollocks.

For that matter, IIRC the *maximum* healthy weight recommended for women my height (5'3") is around 125. The last time I weighed that much, I was skin and bones. It's hard to gauge how much I should weigh, since I've put on a lot of fat as well as muscle over the last few years, but it's hard for me to imagine that I could look healthy at anything much below 140. (I clock in at around 170/175 now, which is morbidly obese according to the charts, but given that I don't even need to shop in the "women's" section in the store, that label seems misapplied. Yes, I'm too fat and could stand to lose at least 20lbs. But if I'm morbidly obese, then I don't know what to call larger people!)

[kay.livejournal.com]

BMI says nothing ... it doesn't say anything about how the weight is built up. Water and muscle weight are not seperated from fat mass, so just toss the whole BMI thing away :)

[bopeepsheep.livejournal.com]

It really is nonsense. My target weight is ~150lb and I'm 5ft6. At 130lb I look anorexic, because of the size of my ribcage and pelvis. But that would give me a BMI of 21, which is slap bang in the middle of normal. The lower end of normal (18.5) would require me to be 115lb or 8st3, which I haven't weighed since I was 19 and living on vodka and cigarettes and thin air (Bridget Jones? moi?); the upper end is 154 (BMI of 24.9) which is 11st, a much more reasonable figure and one that looks good on me as it happens. How can that be acceptable for my height and for someone over six inches taller? It's ridiculous.

[lilactime.livejournal.com]

BMI calculations are only slightly more sophisticated than those awful height/weight charts that were used by insurance companies thirty years ago. There is no accommodation of age, muscle mass, or bone density, or a general level of overall fitness. At my most recent physical, the nurse weighed me and calculated my BMI and I made her black out the BMI number on my file. It's a stupid caculation that should be done away with, as it is useless at its best and harmful at its worst.

[ceruleanblue3.livejournal.com]

The BMI calculations aren't accurate for athletes, or anyone, really, with a lot of muscle. IIRC, there are 'obese' Olympic athletes, who aren't obese at all by any sane world's standards. It also fails to take frame size into consideration.
It is quite worrying that they'd have you as some sort of mobile corpse though. No wonder there's a corresponding epidemic of anorexia and bulimia.

(btw, I got the meme doodah. ta.)

body fat

[jen-c-w.livejournal.com]

they're getting more into measuring %age body fat in europe - better non?

[adjectivegail]

It's trivially obvious that the BMI statistic exaggerates obesity among tall people and does the opposite for short people
I'm not sure I agree with this, but 1) I'm not any kind of a mathematician and 2) I'm short and fat so I guess I would disagree (I interpreted your sentence as '... and the obesity of short people is under-expressed by the BMI', feel free to tell me if I'm wrong). But. The BMI says that I need to lose a minimum of one quarter of my body weight in order to stop being overweight/obese and become 'normal'. Now, yes, I could stand to lose a fair bit of weight, but I don't think that much, and certainly not more! Even if it happened over a period of years, I would quite frankly be alarmed to lose that much weight. Basically I don't think the BMI is any more accurate for short people than than it is for tall people, that it is for especially athletic people - especially athletic women - than it is for... *waves arms* many different kinds of people. Mind you, I ranted about the BMI in my journal not that long ago, so I guess I would say that :)

[klig.livejournal.com]

I'm 5'10" and pretty slim. I was a skinny bastard some years ago and yet was considered ok by the bmi. Not only did I have no fat at all, I also had no muscle.