# Training & Nutrition - The Weather Channel's Bogus BMI Calculator

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Totoro
07-26-05, 09:52 AM
So I check out the BMI calculator and I put in my height and weight (5'11" and 178 lbs). It says that I am in the normal range, but borderline overweight. On the other hand, most people say that I am relatively thin. So what is normal according to the Weather Channel? Well, it begins at 133 lbs. WTF. Perhaps that's normal in Somalia or Bangladesh, but it would be considered anorexic in America.

Check it out here:

http://www.weather.com/outlook/health/fitness/tools/bmi

bmike
07-26-05, 10:22 AM
You'll probably get the same result at CTS (http://www.trainright.com/folders.asp?action=display&record=3)

alison_in_oh
07-26-05, 11:00 AM
BMI was not invented by the Weather Channel. :) It's a statistical tool used to group people approximately according to how much weight they're carrying around on a frame of a particular height. It makes no difference between large and small framed people, between muscle and fat.

If your BMI is above 25, you are a member of a group of people who are more likely to get certain chronic health problems. (Yes, a lot of very muscular people are above BMI 25. The statistics do not break these people out separately and there's no way of knowing if carrying weight in the form of muscle could be detrimental over time.) If your BMI is below 18.5 you are a member of a group of people who are more likely to die than the general population. :eek: And if your BMI is between 18.5 and 25, you're probably A-OK as far as chronic health problems but if you want to be in *good* shape you should get some different numbers to work from besides that very simple equation. :)

stupidvaghole
07-26-05, 11:02 AM
178 is borderline overweight for 5'11. Unless youre muscular in which case the BMI doesnt really apply to you anyway, im 5'11 155ish and ive still got a little bit of fat around the mid section. Basically the BMI is a pointless chart that doesnt apply to half the population.

Totoro
07-26-05, 11:28 AM
Basically the BMI is a pointless chart that doesnt apply to half the population.

I guess it's designed for the couch potato half. I imagine that most people on this forum are in the half that BMI is pointless for. Also fitness usually correlates with more muscle and less fat. Since muscle weighs more than fat, the more fit you are, the more "overweight" you'll be. For example, in one thread, a 5'7" rider describes himself as extremely fit, but he weighs 190 lbs. So, if BMI is bogus, why use it?

recursive
07-26-05, 12:25 PM
I guess it's designed for the couch potato half. I imagine that most people on this forum are in the half that BMI is pointless for. Also fitness usually correlates with more muscle and less fat. Since muscle weighs more than fat, the more fit you are, the more "overweight" you'll be. For example, in one thread, a 5'7" rider describes himself as extremely fit, but he weighs 190 lbs. So, if BMI is bogus, why use it?

It's pretty much common knowledge that BMI is not a good measure of anything. People love short little quizzes with results that tell them about themselves even if the results are totally bogus. (see the grocer's magazine rack)

cheebahmunkey
07-26-05, 12:57 PM
a much better measurement is body fat %. Only problem is to get an accurate measurement, you actually need to go out and use equipment capable of measuring it. So you can't just sit at your computer and plug in a few numbers.

Santaria
07-26-05, 03:27 PM
Oddly, my numbers are currently:

177lbs. @ 6'
17.5% Body fat
Current BMI - 24

I'll shrug and be happy considering, when I started this grand change the numbers were

301@6'
32% Bodyfat
40.1 BMI

BMI doesn't mean anything to anybody who does more than about an hour a day worth of exercise. The minute you go beyond that, your not worried about 'just maintaining weight' and therefore the benefits of reviewing your BMI fly out the window, fast.

Ideally, I'm working towards

165@6
8% Bodyfat
22.4 BMI

Everywhere I looked, I found a label that stated: BMI doesn't mean jack for competitive athletes

HWS
07-26-05, 05:13 PM
Maybe not for competitive athletes, but the USAF is using it as part of their fitness assesments. http://www.af.mil/news/story_print.asp?storyID=123010965

Totoro
07-26-05, 05:19 PM
Maybe not for competitive athletes, but the USAF is using it as part of their fitness assesments. http://www.af.mil/news/story_print.asp?storyID=123010965

But the article notes that waist measurements would be used instead of BMI if the score is above 25. Fighter pilots in particular need to be very muscular to withstand the g-forces.

DeanC
07-26-05, 11:38 PM
178 is borderline overweight for 5'11. Unless youre muscular in which case the BMI doesnt really apply to you anyway, im 5'11 155ish and ive still got a little bit of fat around the mid section. Basically the BMI is a pointless chart that doesnt apply to half the population.

Good lord, 178 borderline overweight? I'm 5'11" and my lean body mass all by itself is 178lbs...

I'm carrying more bodyfat than I need right now, but I'm in no hurry to get to 0%.

SSP
07-27-05, 12:21 AM
I guess it's designed for the couch potato half. I imagine that most people on this forum are in the half that BMI is pointless for. Also fitness usually correlates with more muscle and less fat. Since muscle weighs more than fat, the more fit you are, the more "overweight" you'll be. For example, in one thread, a 5'7" rider describes himself as extremely fit, but he weighs 190 lbs. So, if BMI is bogus, why use it?

BMI, while overly simplistic, is not "pointless" or "bogus" for people interested in cycling. In general, the lower your BMI, the better you'll perform on the bike (up to a point, anyway).

At 6' tall, I used to weigh around 182 after a number of years of consistent cycling. I considered this my "set point" weight, and (like you) thought that it would be crazy and difficult to get my weight down much lower. At that weight and height, my BMI was 24.7, I was regularly riding centuries, and most people thought I looked pretty fit.

But, over the last few years I've intentionally played with lowering my weight through diet and exercise. I'm now around 166, and I'm way, way stronger on the bike (especially in the mountains). A few weeks ago, I set a personal best on a century ride in Colorado - 105 miles with 3500 feet of climbing in 4:50 (average speed of 21.7 mph). 10 days later, I completed all 5 passes of the Markleeville Death Ride (http://www.deathride.com) (129 miles, with 16,000 feet of climbing) in 9:32. Not bad for a guy who's 52 years old.

Bottom line: you may think it's nuts to get your weight down lower, but you may be surprised by the results if you can pull it off.

As other have noted, body fat measurements are a more meaningful measurement for the athletically inclined. I've included an easy-to-use estimator in my programs (see sig line), or you can find a free one online here (http://www.he.net/%7Ezone/prothd2.html).

soni_guin
07-27-05, 01:02 AM
BMI IS pointless and bogus.

Any index that says an athlete is obese gets BS called on it.

I don't even bother calculating BMI... i use a body fat percentage.

When I started in late january, I was 225 at 5'6... body fat percentage was 35%.
Now, I'm at 168, still 5'6 , and my lean mass is 125 lbs, 25% body fat (I have at least another 30 lbs to go)

SSP
07-27-05, 01:24 AM
BMI IS pointless and bogus.

Any index that says an athlete is obese gets BS called on it.

I don't even bother calculating BMI... i use a body fat percentage.

When I started in late january, I was 225 at 5'6... body fat percentage was 35%.
Now, I'm at 168, still 5'6 , and my lean mass is 125 lbs, 25% body fat (I have at least another 30 lbs to go)

BMI is certainly not a perfect measure - it doesn't say anything about fitness, for instance. But, for most people, it's a reasable surrogate for "fatness", and it's a lot easier to calculate than body fat.

For the small percentage of the population who are built like NFL linebackers, BMI doesn't mean much. But, for the other 95% of the population (you and me included), it's a reasonable way of expressing how heavy or light one is.

FWIW, BMI has also been linked to mortality statistics in several well-designed, large-scale studies. For instance, the New England Journal of Medicine published a study in 1999 that looked at mortality statistics for one million subjects over a 14 year timespan. Their findings included:

"The risk of death from all causes, cardiovascular disease, cancer, or other diseases increases throughout the range of moderate and severe overweight for both men and women in all age groups."

"In healthy people who had never smoked, the nadir of the curve for body-mass index and mortality was found at a body-mass index of 23.5 to 24.9 in men and 22.0 to 23.4 in women."

http://content.nejm.org/cgi/content/full/341/15/1097

If you've got links to scientific studies showing that BMI is "BS", please post them.

lauren
07-27-05, 08:13 AM
Mine's 19.6 and I definitely have a little gut to loose, but I'm fairly small framed.

alison_in_oh
07-27-05, 09:11 AM
Mine's 19.6 and I definitely have a little gut to loose, but I'm fairly small framed.

You're in the "normal" range. You are not at particular risk of chronic health problems of the sort associated with carrying excessive weight. Congrats!

If you want to actually evaluate how lean you are, get your body fat measured. But really there's no reason to bother if you are active and fit.

Santaria, same for you. You are in the normal range. You've taken away a major risk factor. Quitting smoking was also taking away a major risk factor. Way to go!

Being healthy is different from limiting risk factors. Your diet goes a long way toward promoting health. You'll probably find that as your fitness increases, your body fat stabilizes below 15%. Being fit makes you healthy. Eating well makes you healthy. Having particular numbers associated with your body composition doesn't.

soni_guin, how does your example show BS? You moved from 36.3 to 27.1, which dramatically decreased your risk factors. When you reach your goal weight, if you maintain muscle you'll be at a fit and lean 10% body fat, and your BMI will reflect a normal, low-risk 22.3. A fine example of how using BMI as a rough guideline is a reasonable approach to decreasing the incidence of chronic problems!