[ashpelham]

I just finished reading an article over at CNN.com, in the Health section, saying that most of the time, truely obese people (using the BMI calc) mis-classify themselves as being less than obese, and therefore are not paying enough attention to their weight and overall health.

The article went on to say that many physicians and researchers feel that BMI is of limited use because it does not take into account body composition, citing the fact that athletes and those who lift weights regularly might be on the upper end of overwieght for thier heights, but are in fact, very lean on fat.

So, why the heck are we sending mixed messages like this to a nation that is on the brink of a health crisis as it relates to weight and health? Why not drop the calculation altogether? Or at the least, seriously modify it? My understanding is that is quite an old calculation, designed before we knew what we know about the body now.

 

[Argentius]

"That which is measured, tends to improve" is a popular saying among economists and others.

It's probably a little outdated, and surely it's not relevant for someone who's an athlete and already knows they're fit.

But, for the general public, measurements that would be "relevant" -- that is, take into account body composition, etc., would be too difficult to use as a "rule of thumb" cross sectionally.

I'd venture that the vast majority of Americans who measure up as obese aren't that way because they are bodybuilders with too much muscle mass, nor have exceedingly strange bone density or something.

It may be sensationalistic, but this nation is far fatter than healthy, and any measure that might help show that and thus potentially help promote change gets some kudos from me.

 

[Dwayne Barry]

Why not drop the calculation altogether? Or at the least, seriously modify it? My understanding is that is quite an old calculation, designed before we knew what we know about the body now.

I bet it's superior to weight alone in it's predictive value of health status. Afterall all it is an attempt to take height into consideration. I think the point of that article was that there are consequences of being "obese" based on BMI classification yet only a small percentage of obese people consider themselves obese and hence able to heed the warnings related to obesity. Sure there could be a few obese people (much more likely overweight rather than obese though) due to having more than the normal muscle mass for their height but I think the article even says most overweight/obese people are simply fat. There are other measures out there rather than weight alone or BMI that have predictive value for health status such as waste to hip circumference (because abdominal fat in particular is associated with negative health consequences). But BMI is simple and probably has become widely used b/c it is better than weight alone.

 

[sol 518]

Some states are now including a report from the school with the kids BMI. That ought to make people aware of the problem, I wonder if the parents will actually make any changes to the diet and activity.

http://www.healthyarkansas.com/news/pr_bodymass_093003.htm

 

[Under ACrookedSky]

BMI was never meant to be used for individuals. It was meant to correlate mortality rates with obesity across large populations. For that it works well. For individuals it's not very useful.

 

[Kerry Irons]

Individual usefulness

For individuals it's not very useful.

As others have noted, for people who are muscle dense, it gives a false measure of being overweight. However, for the VAST majority (90+% ?) of people, it will tell them that they are too fat - like they didn't really know that already and were just kidding themselves about being "big boned." There was a flash-in-the-pan poster here a while back claiming that small changes in BMI had significant effects on health without knowing a thing about the individual, and effectively saying that drastic things happened when you went from 24.9 to 25 (I'm overstating his case for fun!), but in western nations today, if someone has a BMI over 30, there's a 99% chance that they're just plain obese.

 

[TurboTurtle]

As others have noted, for people who are muscle dense, it gives a false measure of being overweight. However, for the VAST majority (90+% ?) of people, it will tell them that they are too fat - like they didn't really know that already and were just kidding themselves about being "big boned." There was a flash-in-the-pan poster here a while back claiming that small changes in BMI had significant effects on health without knowing a thing about the individual, and effectively saying that drastic things happened when you went from 24.9 to 25 (I'm overstating his case for fun!), but in western nations today, if someone has a BMI over 30, there's a 99% chance that they're just plain obese.

I think the OP is refering to the other end of the spectrum - those with very little muscle show to be too healthy with the BMI. - TF

 

[Fredke]

So, why the heck are we sending mixed messages like this to a nation that is on the brink of a health crisis as it relates to weight and health? Why not drop the calculation altogether?

Do you propose an alternative or tell people that because BMI is imperfect they shouldn't use any number?

 

[Sub]

Who are we trying to kid. I don't need to ask someone how tall they are or how much they weigh before deciding if they are obese or not. Good points have been made, both having to do with muscle mass. Some may have more, some may have less and their BMI will not be a true indicator of their health. I'm considered borderline obese going by the BMI numbers but I have huge quads and calves that are defined (not fat) and my bootie is plump as well. Do I need a BMI to tell me I'm currently 10 lbs over my racing weight? Nope. I would guestimate that 80% of people are moderately overweight to obese in the U.S.

 

[psuambassador]

I think young people have to be especially wary of the BMI, as I would guess it could very easily lead to eating disorders, especially amoung young female athletes. There are many high school and college track athletes that have significant muscle, are in great shape, but the BMI tells them they weight too much. I think the BMI should be thrown out and I'm surprised there have been no law suits over those that use it yet.

 

[bas]

Not everyone is a lean bodybuilder, and mostly everyone is FAT in case you haven't noticed.

I just finished reading an article over at CNN.com, in the Health section, saying that most of the time, truely obese people (using the BMI calc) mis-classify themselves as being less than obese, and therefore are not paying enough attention to their weight and overall health.

The article went on to say that many physicians and researchers feel that BMI is of limited use because it does not take into account body composition, citing the fact that athletes and those who lift weights regularly might be on the upper end of overwieght for thier heights, but are in fact, very lean on fat.

So, why the heck are we sending mixed messages like this to a nation that is on the brink of a health crisis as it relates to weight and health? Why not drop the calculation altogether? Or at the least, seriously modify it? My understanding is that is quite an old calculation, designed before we knew what we know about the body now.

 

[SilasCL]

I think young people have to be especially wary of the BMI, as I would guess it could very easily lead to eating disorders, especially amoung young female athletes. There are many high school and college track athletes that have significant muscle, are in great shape, but the BMI tells them they weight too much. I think the BMI should be thrown out and I'm surprised there have been no law suits over those that use it yet.

This is crazy. I can't think of a single woman on my girlfriend's track team (college D3) who would be considered overweight by the BMI. Most were probably low BF% but still in the normal range, as they had a lot of muscle. The field team, mostly shotput and discus throwers, are a different story, and probably are overweight, facing the health risks that go along with it.

Do you think elite athletes are basing their health concern on their BMI number anyways? They are much more concerned with their training, results and hitting new personal records.

The only elite athletes who could be considered overweight are those in sports where increased mass is a big advantage. Track is not one of those.

Silas

 

[ru1-2cycle]

Proven.

I proved my post to you. Maybe you could not understand my medical references...

As others have noted, for people who are muscle dense, it gives a false measure of being overweight. However, for the VAST majority (90+% ?) of people, it will tell them that they are too fat - like they didn't really know that already and were just kidding themselves about being "big boned." There was a flash-in-the-pan poster here a while back claiming that small changes in BMI had significant effects on health without knowing a thing about the individual, and effectively saying that drastic things happened when you went from 24.9 to 25 (I'm overstating his case for fun!), but in western nations today, if someone has a BMI over 30, there's a 99% chance that they're just plain obese.

 

[Pablo]

Good for what it's worth.

I've always understood the BMI as a blunt analytical tool, like the so-called national poverty level in economic statistics. The BMI is a good (very) rough estimate of body composition that should be the starting point but not the conclusion of people's health analysis. That said, it seems like it's useful for people to start to get an idea about their health as long as they don't use it as the last word.

Anyway, like other posters, the BMI has me as nearly overweight (5'10" 165 lbs) which is a function of my earlier days lifting weights and not donuts. But, as others have pointed out, the BMI isn't designed for actual athletes to gague their health.

 

[buck-50]

I've found that BMI gives me a good benchmark to shoot for- Supposedly, a 6'2" guy should be around 185 lbs. I used to laugh at that number, and complain that it didn't take into account muscle mass, etc. Even though I weighed around 240 lbs, I didn't think I was obese. I tend to store fat all over rather than in one place, so I just looked like yer typical "big guy".

This year I decided to actually listen to my doctor and lose some weight- now I'm down to 210 lbs, and now that I've lost 30 pounds, I can see where the remaining weight is hiding. I don't know if I really have 25 more pounds to lose, but then again, I didn't belive I had 25 pounds to lose before, either.

So, BMI is giving me a pretty solid guide to getting myself in good shape. I'm sure that for elite athletes (if yer on a team, yer probably elite) don't need it, but for those of us who just ride to ride and don't train or have a coach, it's a good indicator. I may never be able to reach 185, that number may be flawed and it may not take into account any number of factors, but it's better than nothing.

One more thought- I think we've skewed the idea of obesity so badly in this country that it's hard to see yourself as obese- I mean, when I think obese, I thing some guy in a trailer who can't get out of bed, or someone who can't see his feet. It's hard to think of yourself as obese when you can ride 100 miles on a saturday.

 

[ashpelham]

Thanks for the replies everyone. When I think of myself, I think that at 200 pounds, I could stand to lose "a couple". It's so morphed out of proportion, because I eat a very sensible diet, and obviously exercise much more than your average joe. But when I go to races, or even when I look in the mirror, I don't like what I see. I see pudge. But when I'm not riding with my team, I look around at average joe's, and I see fat, fat, fat. And I look a good bit slimmer than those people.

Chubby as a kid, I kind of grew up and out of that some. But I live behind a desk, working 60 hours a week. I eat light as I can, but I seem to let stress dictate how I eat, sleep, workout, etc.

I think it probably is skewed. We have such a mindset as to what fat looks like, that what was fat 50 years ago now seems thin.

 

[Kerry Irons]

Good point

We have such a mindset as to what fat looks like, that what was fat 50 years ago now seems thin.

If you look at virtually any group photo from around 1900, you would say that nearly everyone was really skinny. That's how everyone used to look before we started riding a half mile in our car to get to the 7-11.

 

[Dwayne Barry]

I think it probably is skewed. We have such a mindset as to what fat looks like, that what was fat 50 years ago now seems thin.

Except just as many people ~75% accurately assessed themselves as overweight as normal weight. I think the problem is the word obese has a very negative connotation to it. Consequently few people are willing to label themselves as such even if they are, by definition according to BMI, obese.

Not that I don't agree with you. When I've traveled outside the US it is really striking on returning how fat this country is.

 

[Dwayne Barry]

It's hard to think of yourself as obese when you can ride 100 miles on a saturday.

There's probably not too many obese people out there doing that, lots of overweight people doing it though.

FYI, BMI (wieght in kg divided by height in meters squared) classifications:

Underweight <18.5
Normal 18.5 - 25
Overweight 25 - 30
Obese >30
Mobidly Obese >40.

For a 6 footer to be obese they'd have to weight >220 lbs, for a 5'10 person >205 lbs.

 

[psuambassador]

Maybe not in D3, but in D1 I saw a lot of this. Jumpers, Sprinters etc had a lot of muscle in their legs. They were very lean, yet weighed more than the BMI said they should.