100 lb. Club - Have BMIs changed?

View Full Version : Have BMIs changed?

07-24-2010, 05:11 PM
Have they changed the amount of pounds that go into BMIs?

I was reviewing my very comprehensive list of mini-goals and decided to put in when I get to 'overweight' (164) and when I get to 'normal' (136).
I was quite surprised that 136 was the first of 'normal', because that's what I got to in '04, and I thought I'd been normal for a few pounds before that.

On re-reading my list - I only put it together last year - I already had the overweight and normal marked but overweight was 176, and normal was 141. I didn't invent those figures, they must have been true last year. I wondered if anyone else had noticed they'd changed.

07-24-2010, 05:23 PM
The World Health Organization BMI categories have been unchanged since at least the 1990s. In 1998, the US changed its BMI categories to be in line with the WHO, lowering the definition of "overweight" to a BMI above 25. I'm not aware of any other recent changes?

I know it sounds silly, but could you have been using a different number for your height?

07-25-2010, 01:13 AM
I did a BMI calculator today on a website for a diet quiz thing. It said my BMI was 43.something. I'm Class III Obese? I guess. Whatever.

My point is, for some reason I thought my BMI was lower than that, and the last time I checked my BMI, was at 293.

I don't rely on BMI. At all. I think it's borderline useless, in all honesty.

12-19-2010, 07:26 PM
I was just gazing at my bmi calculator again, 5 months on from the original post, still very happy to be 'just' overweight, and I spotted a teeny tiny footnote - that until recently this particular site had been adding 1 BMI point per year over age 45, so that yes, during my last big weightloss drive, 2002-2004, the bmi 'allowances' for overweight and obese etc Were higher!

I know it doesn't matter, just glad to know that I wasn't totally insane!

12-19-2010, 11:38 PM
I stopped thinking BMI was all that important after my husband's friend told me he was obese by BMI charts. When he learned that, he asked his doctor whether he needed to lose weight, and his doctor laughed. He told the guy that he didn't need to lose weight, but if he wanted to, it would be safe to lose something like ten pounds, so that's what the guy did (and he's technically still in the "obese" BMI category, even though he's all lean muscle, and no extra fat).

Those ten pounds took the guy from super buff, to a very tiny smidgen more super buff. (His well-defined six pack, got marginally more defined).

This is a guy whose friends ask him to "keep his shirt on" around their wives, so they don't have to hear their wives tell them how good their friend looks.

He's also got all these tribal warrior tattoos, which I'm normally not a fan of, (because they only look good on a guy with an actual warrior's body. Unless you're super lean, yet heavily muscled they just look ridiculous).

Well, they don't look ridiculous on this guy. He's the buffest guy I've ever seen "in real life."

His falling into the obese category is laughable. And it's not just a "skewed sense" of lean, because literally this guy's muscles are so well-defined, there's no room for the fat to be hiding. Even a few ounces of fat would obscure muscle definition, and you can clearly see and identify every muscle
on this guy (and because he tends to wear kilts and sleeveless shirts, you get to see a lot more than you ordinarily would. There literally is no place fat could be hiding). I've never seen a man with such calf definition outside of body-building magazines (not only is he a gym rat, he also is also into sports and bow-hunting).

I am not an athlete by any stretch of the definition, so for me, I'll probably have to overestimate, rather than underestimate BMI. But it does remind me that BMI has to be taken with a grain of salt.

12-20-2010, 12:22 AM
I'm a health care provider and I really want to stress that BMI is a useful screening tool.

For my height, 5'8" the range of normal is 39 pounds wide-- from a low of 125 to a high of 164.

Obesity is so prevalent right now that we are used to seeing a lot of overweight and obese people around. Looking "average" does not mean that a person is "normal" from a health perspective.

BMI is just an average range of weights based on your height. But if you fall way above that range, you can bet that it's because from a health perspective you have too much body fat. If you are trained athlete and you KNOW that your body fat percentage is normal, then ok. But for most of us, there is no reason we shouldn't weigh inside that range of normal. In fact, most of us, probably should weigh somewhere in the middle of that range.

I remember clearly sitting in my doctor's office and having her show me that I had a BMI of 40+. I was SO far away from the normal range that I seemed to have no hope of getting there. And I'm still not there. But I do believe I will get there eventually. Just because I was WAY above normal, did not mean that the definition of normal was wrong.

12-20-2010, 04:14 AM
Yup, I'm a big fan of taking BMI seriously. Obviously, if you're keep-your-shirt-on toned, then it's a false reading! And I suppose some of the borders between the categories could get blurred as to whether you're just into normal or still just into overweight. Otherwise, some of really need the wakeup call of finding we're BMI 44.3 (morbidly obese).

I've read a lot of posts recently (kaplods, this is not including yours :) ) telling people that they shouldn't worry that their BMI is XX, because it's not an exact science; that they shouldn't be sad that they're defined as morbidly obese. Ladies, MORBIDLY. That means 'at risk of death'!!! damn right we should be worried and upset - enough to do something about it.

OK, I'm going to have to back off my soapbox here but while I never see the point of deliberately upsetting people just for the sake of it, I equally never see the point of just being 'nice' when people's lives are at risk.

And all I wanted to say in my update was yay, I'm not mad, the calculator I use DID use to have higher allowances. I'm losing weight, not brainpower! :D

12-20-2010, 06:12 AM
I use this, in a spirit of enquiry. Rosinante, it's very interesting from a UK perspective, as it shows at which US percentile our BMI lies.


12-20-2010, 06:24 AM
Yup, that's the one I use, and used. I think I'm at the 55th percentile. :)

12-20-2010, 07:21 AM
You have to take the BMI for what it IS: a very rough guideline.

I see they've changed the Wikipedia entry, and I doubt I've posted enough to link it anyway, but when you take the time to look into the origins of it, it was basically a way of doing this:

Tall and thin
Tall and fat
Short and thin
Short and fat

I am, of course, simplifying things...but only just. Your BMI is a rough estimate at best, and not to be taken too seriously.

DixC Chix
12-20-2010, 09:43 AM
Weight scales and BMI calculators and measuring tapes are all tools that helps us perceive health. So are thermometers, BP cuffs and bloods test, etc. If we really wanted to accurately know our own BMI then we should invest the $$ to have the hydrostatic body fat test. *shrugs*

I have used the bioelectrical impedance analysis that measured me to be lower in body fat % than the BMI calculators. Regardless, its just a tool that tells me I should lose weight and exercise.

12-20-2010, 10:19 AM
I think BMI works great as a guideline, as long as that's how you're using it. You have to understand what it can and can't tell you. Just like the scale.

If you only worried about the immediate (right after the meal) result on the scale, you would judge food by it's weight, not it's calorie content. A candy bar would seem a better choice than a pound of broccoli, because the candy would cause a 2 ounce gain on the scale and the broccoli a pound gain.

That's a ludicrously extreme example, because most people can see the fault in the logic immediately. But we see less extreme and therefore less obvious examples all the time, like people afraid to exercise because it might result in muscle (and therefore weight) gain, or people obsessing about avoiding all salt or all fat because it's "bad," or going on super extremely low carbohydrate diets, not because they feel best on them (some people may), but because it allows them to see the lowest numbers and greater weight loss on the scale in the least amount of time.

Moderation really is a difficult concept to master (probably because there is no one-size-fits-all approach).

12-20-2010, 01:19 PM
IDK if anybody in here fits into the "minority" category except for me (black and native american) but emerging studies shoe that BMI may need to be re-calculated for other races, because we have different makeups and compositions. I still want my BMI to say "normal" one day, but knowing it was based off a caucasian woman and not made with me in mind, I also will call it a "rough estimate" but if I were "morbidly obese" I would be scared...well I'm regularly obese and I'm terrified.

12-20-2010, 07:23 PM
I think BMI breaks down at "the outliers". I'm 6'4" (could pass for 6'5" if I stand straight.)

BMI said at my highest weight, I was borderline moderate overweight / obsese with a 29.6 score. :sorry: But I didn't look different than most paunchy guys my age. It may work more as intended, for people in the common and prevalent height ranges.

12-20-2010, 07:44 PM
Well, I would say two things.

Of course, it's a health screening tool. It's a quick way for an individual to figure out whether his or her weight is in the normal range.

You might be a little over or a little under and still be perfectly healthy, but if you are WAY over or WAY under then you probably could use some adjustment.

Think about it this way. Most people don't know how much other people weigh. My DD, who is sixteen, was SHOCKED to learn that 175 made her overweight for her height. She had no idea until her pediatrician told her.

She lost ten pounds and now is considered normal. Isn't it better that she realized that she was a little overweight BEFORE she had twenty or fifty or even 100 pounds to lose?

So, I don't see why people quibble with BMI. It's a quick way to see if you are around the right weight for your height. Then you have to fine tune it for yourself, but you also have to realize that if you weight 30, 40 or 100 lbs over a "normal" BMI that it's probably excess fat that is getting you there.