Wednesday, July 2, 2008

BMI, SchmeeMI

Ugh. This calculator is not an accurate measure of body weight and health. We all know it doesn’t measure the amount of fat vs muscle you have, so you could be deemed overweight by the damned calculator, when in reality, you just have a lot of muscle and probably look smokin’ in a swimsuit.

So, my question is this:

Why do health professionals (coughmydieticiancough) still use it? Really. Please? Someone tell me!

22 comments:

KC Elaine said...

I hate BMIs too. don't know why I live my life by them. :/ Not only does it not take into account muscle, frame, etc., it isn't even formulated correctly. Here's a better BMI calc for tall and short people:
http://www.mines.edu/~gmurray/BMIApplet/BMIApplet.html

Jackie said...

No answer for you my dear. But I love my B!

xo Jackie

KC Elaine said...

sorry - did I just give you a new tool to obsess over?

jana bananas said...

Yes, I think BMIs aren't the most accurate measure of health. However, I think they're still good as a guideline or ONE measure of it.

Isn't it more skewed for those that have a higher BMI - i.e. your muscle example? Whereas your BMI is low...I don't think that's as inaccurate of an indicator. Still, I think your dietitian might be putting too much focus on it. Maybe.

KC Elaine said...

honestly, BMI charts prescribe lower weights than "Ideal body weight" charts, which my dietician goes by. She says I have to stay at at least 95% IBW. I'd be cautious of accepting a low BMI as healthy, tho - if you have muscle then it is even lower than it looks. when it comes to modeling and such, bleh, I can think of no better way regulate the industry. But a dietician could certainly use a more accurate system.

Carrie said...

Okay, so here's my public health training and nerdiness rubbing off.

A BMI is only a screening tool- it was designed to give you a rough estimate of weight to height. At either extreme (low or high), there is going to probably be an indication of health. BUT they're not diagnostic of anything.

My dietician says she always tells her patients they need to be midrange of a healthy BMI before she'll start to consider them weight-restored. MINIMUM healthy weight for recovering people. Growth charts help refine that.

But like in public health, BMI is only an estimate at a healthy weight. And the health effects of a few extra pounds are essentially non-existent, especially when compared to going batty because you're a few pounds under your healthy weight.

I had it easy- I got sick after I had been at an adult height and weight for several years, so the math was straightforward.

Cammy said...

I agree with you, BMI is a good tool *in theory* that more often than not is not that useful for real life bodies. My dietician has never even mentioned BMI, but she does do regular body composition analyses, which are much more informative.

zubeldia said...

I know it's hard to hear, chicky, but while the BMI is absolutely problematic - especially in terms of not taking into account muscle - when it comes to UNDERweight the BMI is likely a good screening tool, though certainly I don't think it's fool-proof one. Ideal weight, to me, involves:

A weight which allows your endocrine system to function properly. A weight where your body does not breakdown its own muscle tissue (including heart) to survive. A weight which doesn't put your bones at risk. A weight at which, if you become ill, you can afford to lose some pounds. A weight where your cognitions and emotions are not being shutdown. Crucially, a weight that is maintained through intuitive eating - and not by AN rules, anxiety, etc. A weight which you're indifferent to and thus does not invite intrusive thoughts.

brie, your anorexia does not like this, and I think you may have to let go of a number, whatever it may be, to truly heal. I think it's time to let it go, sweet one.

What do you think?

love you, Z

Kathy with a K said...

having seen a nutritionist at one time in my life, and having been free of any relapse of any eating disorder for about 20 years...I must say, in the great scheme of things, the nutritionist had little to absolutely nothing to do with my recovery. BMI's are stupid. (my own opinion)
AND, to top it all off, eating disorders have little to nothing to do with food anyway. I think there's enough measuring and calculating going on in the mind of any ED'd person; don't need a BMI. Stupid, I say. Just Stupid.
Was that clear? :)

Emily said...

I think bmi's are somewhat useful when monitoring underweight people, but not so useful to people who are weight restored. It's certainly not useful to me, and my dietician doesn't strictly use it with me to monitor weight loss progress. She takes it into consideration, but doesn't only go by that.

Keely said...

A nutritionist I used to see (not at the center) said that the ideal weight is 100lbs for 5'0'' and then 5 lbs for every inch you are taller than 5 feet. That's the only other calculation system I've seen other than BMI.

b said...

First off - Ky, you didn't give me a new tool to obsess over, silly. :) I'm going to check out the link though, so thanks.

Zuby, you are too right, as always. I suppose I get frustrated when I'm told not to work myself up about numbers, but my treatment team does. I know it sounds like I'm trying to defend my Ed, and I don't mean to - but I *feel FINE.* So what if my BMI says that I'm technically still anorexic? I just don't think it's a one size fits all thing, is all. Genetically, we are all very tall and slender in my family. Some of my sisters have low BMI's but are completely healthy -- have no ED's, etc. So it gets confusing. Also, I swear I'm healthy and no eating of organs is involved right now. :)

Carrie, thanks for your input, too. It made sense - and thanks for commenting on my blog. :)

I suppose I'm just airing out my frustrations. I thought I was gaining weight, heading toward recovery, and now suddenly I'm technically anorexic again because of some damn chart? I don't think so.

Also - Keely - by the weight chart your D gave you other than the BMI...wow. RIDICULOUS. Going by that, my healthy weight would be the weight I weighed shen I delivered Cade. Way too much!

b said...

Ky I don't like your BMI calculator for tall people! It actually made my BMI a teensy bit less than the regular ones! Gah! I'm so not going to show my D that one...

KC Elaine said...

your weigh too much my d says is perfect :(

KC Elaine said...

here's a thought - I know your health is none of my business and I know very little about it except that you are skinny, but it's hard not to think about it when you post about it. have you been tested for marfan's syndrome? That's what they thought Lincoln had. My family has a lot of symptoms of it and they tested us for it back in the 80s...basically makes you lanky, tall, and slender, and internally you have weak connective tissues. My family can fucking menstruate at any weight (my sis got prego at a BMI 16.5), most are (or were) tall and slim (wish I got that part), we have long fingers, small wrists, collapsed lung, etc - all symptoms, but we don't have the full-blown disorder. though I think the docs were hoping to find an entire family with it, fun to study, you know. anyway, I want to gently remind you that you were on bed rest when you delivered Cade. I know I shouldn't take "ridiculous" personally, but it's hard not to when we're the same height and I already disagree with my dietician on my weight as it is.

b said...

Hey K,

I'm sorry. I shouldn't have used the term "ridiculous."

maddog said...

The ideal weight tool that Keely mentioned is a standard one. It's probably just as useful and reliable as BMI. Don't be scared, brie!

Krista said...

Even the five feet 100 lbs plus 5 for every inch is actually on the smaller side of weight charts. On one weight chart I found the minimum recommended weight for a 5 ft tall person is 104 so 100 lbs would less than that. I remember I went to the center with a really tall girl (5'11") and she hated how she had to weigh more just because she was taller, but to the rest of us we thought she looked better when she was at the recommended weight (and we were people with ED'S). I'm sure it's hard to accept a bigger number when you have been underweight for so long, but remember not to let the anorexia talk to into accepting a lower weight as being healthy. We love you Brie. Take care!

Vickyann said...

I don't get bmi's; a friend and I have the same weight and number deemed healthy yet are very different in actual size.

I do use it as indication to keep my weight where it needs to be and not drop any lower.

zubeldia said...

I used to have magic numbers that I would not go over. And then I would have to raise the number, and once I did it became an okay number and I could allow myself to weigh it... and I kept doing that. it is hard when you've been underweight for so long, but you can have a life free from the ed, Brie. It will, I think, mean weight restoration, and while your family may have genes which make you all tall and slender, my sense is that your natural weight would not be an anorexic weight.

Numbers are my undoing, and so a dew years ago I decided that I could not weigh myself anymore. I have accepted that I weigh at least 30 pounds more than I once did, and I know that this now puts me in the healthy range. I longer for my natural weight to be slightly underweight.. alas, I dont' think it is. Even now I think I am maintaining a slightly lower weight that what my body would like.

You deserve a fuller life, honey. I think that certain treatment practices can be very triggering for people. I wonder if you can do blind weights?

Palmtreechick said...

Ditto!! BMI is the biggest piece of crap!! Body fat percentage is a much better/more accurate way of determining one's health. BMI, like you said, does not take into consideration muscle mass. I HATE the BMI. It's stupid!!!

CookieGirl said...

hi sweet brie,

Another public health nerd here, just want to echo what carrie mentioned about growth charts...do you have an adult height/weight, pre-anorexia, to compare yourself with? Very, very few people have BMIs under 18 naturally. Hope you are feeling better today xoxoxo