How reliable is your BMI?

[eminenz2]

I have been doing Cathe's worloute for over a year now and have lost a lot of weight. I am fitter and mopre solid than many "skinny" people I know, even though I am still 5'3" and 159 pounds. According to my BMI, 28, I am 'obese'. I certainly don't look obese.

My physical therapist was just telling me he recently applied for some additional life insurance and the company he was considering told him they couldn't offer him their best rate because he was 7 pounds overweight - this guy is very fit, too, and lifts weights. Totally solid, but yet considered 'overweight'.

When is health and fitness going to be looked at as a collection of factors rather than just a number - weight, BMI, bodyfat percentage, clothes size, etc.?

Augh! x(


Just venting,

Susan G.

 

[Calico]

I was recently told to go by your body fat not the BMI index to judge how fit you are. So I ignore that number and go with my body fat which is slowly coming down. Take a body fat test and see where that puts you.

Hope that helps some

 

[FitnessGoddess]

Susan,

Fitness is looked at as more than just a number.

As for the reliability of BMI--it isn't meant to be a fitness measurement but exactly what it is called a body mass index. I know a couple of overweight people that can out run me any day but that doesn't mean they are any less overweight. Overweight is overweight period. And being overweight is, unfortunately, an indication of your bodies physical well being, not necissarily fitness. Being overweight is bad for your heart & lungs. It makes your heart work hard to get the blood where it needs to go. It means an overweight person has more of a chance of getting diabetes than someone that is not overweight. Regardless of whether a person can lift heavier, run faster, endure longer, if that person is overweight, they have a higher chance of dying of a heart attack than someone that is not.

It workes the other way as well, if I, at 5'6" weighed 100 lbs, I certainly could not call myself physical fit. I would be making myself susceptible (spelled right?) to kidney or liver failure and all kinds of cardiovascular problems. An insurance company would refuse to give me a good insurance rate just as quickly as it would an overweight person.

It's that simple & that complicated. I hope I haven't offended you but those are the facts about being overweight.

By the way, congratulations on the weight loss you have achieved!

 

[naughtoj]

Hey Deborah,

I don't think what you are saying would apply if Susan was actually 155+ pounds and 18% bodyfat.But, I think it would be difficult for her to weight that heavy without a higher fat percentage. I think it is bodyfat that matters here. Bodybuilders can weigh slightly heavy and have a very low body fat percentage. BMI is not totally accurate in that sense. Many bodybuilders with low body fats probably come up as in the "danger" zone on the BMI scale, yet I do not believe that it is the added muscle weight that is going to hinder their health, do you? I do agree with everything else you say though.

However, Susan, at your weight and height I GAURANTEE you are more solid than your "skinnier" co workers and you very well might have a body fat percentage lower than them, but taking a guess, I would still say you have atleast 10-15 pounds of fat to lose. At that weight and height my guess would be your bodyfat would be somewhere in the mid 20's. While acceptable, this would elevate your BMI, and you could improve your health and exercise performance by losing a few pounds (not like you didn't already know this!

I know this because I am the same way. Very mesomorphic in the sense that I put mass on easily, but I do have endomorphic tendencies. Plus, ice cream doesn't help. I work out hard, but when I eat (the bad foods), it is BAD. Therefore, my body fat percentage is not where I would like it to be even with all my muscle. Low 20's now. When I do the BMI, I come up in the "watch out" zone, and I am overweight at 5'0-5'1 and 134 pounds. With my lifestyle now, even with a clean diet it is hard to imagine being able to drop under 125. And it would take extreme sacrifice I think to get to 125!!!
You may have to worry about your BMI, but skinny poeple that don't work out have to worry about their bodyfat. Remember, you are still better off than them because the added muscle should help you shed any extra fat you may have. But remember, genetics are genetics, and you can probably only get so "light".
And, if your body fat is lower than I suggested, please don't be offended. I am just trying to help.
Janice

 

[naughtoj]

Deborah..

" Regardless of whether a person can lift heavier, run faster, endure longer, if that person is overweight, they have a higher chance of dying of a heart attack than someone that is not."


I just CAN'T agree with that. Maybe if you are REALLY overweight, but what if I am 5'0 and I get my weight to, say, 125 and I am now 19% bodyfat. I am still "overweight" to a BMI scale, but I gaurantee my life expectency is more than someone who does not work out, eats crappy food, and looks like Gwyneth Paltrow with 30% body fat. Don't you think?
I am interested in your take on this. Are you within a healthy weight range, I only ask because I knew you were trying to "buff" up. Do you worry about exceeding this range?

Janice

 

[kathryn]

Any measure of fitness that is based on weight (such as BMI or total body weight) won't be accurate for those who have more muscle, since a chunk o' muscle weights more than the same size chunk 'o fat. Body fat percentage is a more accurate indication.

 

[eminenz2]

I think this is a very interesting dicussion - I hope it continues a little while longer.

I also think that there are people, like me, who have struggled emotionally with their weight as well as physically, and find that just the thought of having to lose one more pound, or deny themselves this or that food, just will send them over the edge - !

Just as genetics gave Cathe her fab body (as well as two or three workouts a day!) I think for some people weight loss and especially weight maintenance at the 'correct' weight will always be a struggle, and perhaps could I even use as strong a word as torment?

I know I could stand to lose a few more pounds, but I also know my body well enough to know that a weight like 125 or 130, which is my "healthy" weight, would be a very difficult thing to maintain. I would spend all day and night working out and eating bird seed. I know my body "likes" the 145-150 range, if that makes sense. Not looking for an excuse to be 'overweight', just trying to find a place that makes sense for my body.

You know, I've got those starch-eatin'-Eastern-European-livin'-through-the-famine-and-one-after-another-war genes in my body and I'll be darned if I can't trick them into giving up the extra weight! You never know when the emperor is going to cut off the peasants so you better store your fat now - LOL!

I would be very interested to hear others experiences and thoughts!

Susan G.

 

[munchkin928]

I just wanted to chime in and say that I don't agree that simply being overweight is a health risk either.

There was a study published last year in the New England Journal of Medicine studying which factors were the best predictors of death in a group of men followed over 6 years. The first best predictor was age. The next predictor was PEAK EXERCISE CAPACITY. After that was history of heart disease and years of smoking. Another cool thing was that getting from being in the 'least fit' category to just one stage up (I guess a little bit fit) gave you the most benefit.

Of course, there are some weights that I think definitely indicate poor health. I can't imagine a way to be 5'0" and 300 lbs and not be unhealthy in your diet and exercise lifestyle. However, it's perfectly possible to be 5'0" and 160 lbs and carrying 'excess' weight that would never be a health risk at all. We're built to carry a bit of extra around in case we need it, and some people are built to carry more than others.

When people begin to exercise and eat healthily they tend to lose weight - however, I think the primary benefit comes from the actual choices being made (especially exercise IMHO) and not from the number that you reach.

Right now I am 5'2" and 134 - right on the cusp of being overweight according to some charts. I want to lose weight for appearance reasons, but I do not believe at all that my current weight is a detriment to my health - my thighs touch (well, sort of meld actually), I have big breasts and I have a tummy pooch, but none of those things are endangering my health and I could live a long happy life with all of these physical traits never changing. However, I do need to build up my muscle strength, core stability and aerobic capacity... all of which will probably help me get into those size 6's again.

That's just my take on it... I see a BMI as a convenient quick measure that is not terribly valuable for a very large proportion of our society.

I'm enjoying reading this discussion.

Amanda

 

[roe]

Ditto to what Kathryn said. BMI is a formula that only accounts for height and weight. Lean body mass is not a factor, and we all know that a person can be overfat but not necessarily overweight.

Muscle is denser than fat so it takes up less space, which is why when we lose fat and gain muscle, we look smaller.

-Roe

 

[Aquajock]

Tritto what Kathryn and Roe said. BMI has to be taken with a huge grain of salt because it doesn't tell you about body composition.

Reason #106 that I never weigh myself.

A-jock

 

[Jenne]

My main beef with the BMI is that it is the same old height and weight charts dressed up with extra math. And that just irritates me, since it is sold as being "better than" the old height and weight charts and "more specific" although it includes the exact same variables as the old charts and nothing extra. If it at least included body fat % or waist size, I might be convinced that it's "more accurate."

That said, I think if someone wants to go by the BMI, I would imagine that someone who is healthy and solid and has good endurance but a BMI between 26 and 29 probably doesn't have TOO much to worry about. Losing weight at that BMI COULD end up being a problem IF it throws the person into a cycle of yo-yo dieting or lowered metabolism.

But what do I know. I'm just an interested amateur.

 

[kristi]

"Overweight is overweight period. And being overweight is, unfortunately, an indication of your bodies physical well being, not necissarily fitness. "

Deborah I could not disagree with you more. According to charts my husband should weigh about 190 pounds to not be considered overweight. That is not even physically possible. When he was in high school and college he would work out 1 1/2 - 2 hours every day training for football with heavy weight training & cardio. The lowest weight he could get too was 250, but he was all muscle. By every standard he would be considered overweight, except body fat %, but to look at him he was solid as a rock. It is amazing how someone can look at the scale or BMI instead of body fat and say that someone is overweight. The scale does not take a lot of things into consideration such as body shape, muscle mass, etc. To me, a person's body fat composition is a much better indication of their physical wellbeing.