Why You Should NEVER Use BMI

chivalryder

I'm sorry but body builders and elite athletes are not part of the average population. By the time someone is in that category they do not need an instrument for the average population as a guideline. Look around you--the average person is overweight or obese. many will read this and say--well BMI means nothing--I'm just big boned and not obese.
It is not pleasant t look at the chart and see that you are obese--but it is a wake up call. It is frustrating to lose weight and still be considered overweight. For those of you who are elite fit, you are at the point where the number on the scale means less than your body fat %.
BUT the average person should not toss out BMI because it gives a large range of what is considered healthy. To just toss it out is to stay in denial.

I'm going to have to re-quote this post to say this:

Do I look like an elite athlete or body builder? Will either of those have 21% BF? So what you're saying is that I'm average, and therefore I should use the BMI chart?

MSepp

It is not pleasant t look at the chart and see that you are obese--but it is a wake up call. It is frustrating to lose weight and still be considered overweight. For those of you who are elite fit, you are at the point where the number on the scale means less than your body fat %.
BUT the average person should not toss out BMI because it gives a large range of what is considered healthy. To just toss it out is to stay in denial.

Except that the OP gave a very specific example of how he, an average person, would be UNHEALTHY if he used the BMI to set his personal health goals.

In the last 10 years, I've had multiple doctors tell me to ignore the BMI when it comes to my health. It is, as another poster said, meant for LARGE SCALE observations, not INDIVIDUAL goals. Your health is individual to your own body mass, and the BMI just isn't equipped to account for that.

This is exactly what I was going for. How many people do you know can be considered "average"? In my office, I would say, perhaps 60%, yet anywhere you go on the internet, it's saying that everyone is average.

If everyone was supposedly average, and went by the BMI, they'd be putting themselves in danger, as I would be.

The point I'm trying to make is that the BMI is a good tool in certain situations (see my earlier post) where it is obvious the individual is heading for a certain range of the chart...there's more "wiggle room" at the higher end of BMI than lower. you get below 19 and (unless you're very short), you're starting to flirt with unhealthy weights/underweight which is a risk for being malnourished.

So to say that the BMI should NEVER be used isn't really the right thing to say. For someone who is in the "average" category or slightly above (AKA, most people), it's not very useful. For someone in the class I, II and III obesity categories or who is underweight (BMI of <19), it is a good indicator of overall nutritional status.

cswalker21

Every explanation of BMI I've ever read has come with the caveat that it will read high for individuals with very high muscle mass such as elite athletes. For those people, a more sophisticated measure is needed. However, before anyone reading this thread dismisses BMI as an appropriate guide for their own fitness, I suggest they take a look in the mirror and ask themselves, "Do I really, truly belong in the category of 'elite athlete'?" Perhaps the original poster is in that category, but in my opinion, dismissing what most people will find to be a useful guide by saying "you should never use BMI" is irresponsible.

Goal_Line

I'm not sure I agree that one should NEVER use BMI. I think a better approach is to use it as one indicator. Others to consider are waist-to-height ratio and BF %.

I certainly have a body type that doesn't fit BMI. Current %BF = 23% w BMI 27.9. When I get to 20% BF (assuming no loss of lean mass) my BMI will be 26.6. If I get to 15% BF (which I'm not sure I want to) again assuming same lean mass (which arguably may not be the case with that much more weight loss), my BMI would be 25.2.

JmeJinxx

Yep, about two months ago at 220 I got my BF% calculated and then determined my LBM by that to find that it was ~116. The trainer that did my BF% said that a young woman should strive for 20% LBM so I took that and got ~139, so my UGW is around 140.
SCIENCE!

MSepp

Every explanation of BMI I've ever read has come with the caveat that it will read high for individuals with very high muscle mass such as elite athletes. For those people, a more sophisticated measure is needed. However, before anyone reading this thread dismisses BMI as an appropriate guide for their own fitness, I suggest they take a look in the mirror and ask themselves, "Do I really, truly belong in the category of 'elite athlete'?" Perhaps the original poster is in that category, but in my opinion, dismissing what most people will find to be a useful guide by saying "you should never use BMI" is irresponsible.

Very well put.

it's a good indicator in some cases...but not others. What I consider to be an amazing athlete (though they have notoriously poor nutrition) is gymnasts. But I can tell you now ALL of them would trigger as "overweight" in the BMI chart...HOWEVER, they're in EXCELLENT shape (most have such low body fat % it's disturbing)...Would I estimate their caloric and protein needs as someone who needs to lose weight or is overweight? HECK NO! Their caloric and protein requirement is probably through the roof! However...is one of those girls my average client who is 5'3 and 150 lbs? No...most people are not in that good of shape.

emmygrace2012

It isn't flawed; you're using it wrong. BMI is meant to track an average over a large population.

Yes.
BMI stands for BODY MASS INDEX. What makes up mass? Fat AND muscle. If you're a body builder, you go off of BF%. If you are general population who does not exercise or maintain a healthy diet, BMI works just fine.
BMI is used in corporate wellness plans to track the general population of their employees b/c it is a more accurate standard to go by. There are some employees that are "outstanding" and go for doctor's review to be completely fair. These people are by far the minority.
I use BMI as a measure for employees every single day in my office and have not yet had to challenge a single employee's BMi because of fat vs. muscle mass.

extraordi_mary

It isn't flawed; you're using it wrong. BMI is meant to track an average over a large population.

That is exactly the point though. People look at that as a guideline of where they should be, when in actuality it varies WIDELY by individual, and the guidelines it gives would be incredibly unhealthy for some people. Anything that considers the majority of body builders to be obese should probably not be used as a guideline when setting individual fitness goals.

Saying BMI is flawed is incorrect. It simply isn't meant for your purposes. My vacuum cleaner isn't flawed because it doesn't mop the floors as well, it's just the wrong tool.

WHAT! Physicians use the BMI tool to gauge health! Dumb!

Take this as another example, a major US company is making it mandatory for any employee that has a BMI as overweight to take nutrition classes!!! What is next firing someone for a high BMI because the healthcare/ insurance companies view someone as unhealthy and a liability. I am not talking about highly overweight folks here. I am talking someone like me. I am 5'3 and weigh 136. I am about in the low 20's for BF but just under the overweight category by BMI standards.

ugh now that is bull****. BMI is not the same as health, and I wish more people, especially medical professionals who do NOT have extensive training when it comes to nutrition, would realize this.

I'm straddling the border between "overweight" and "obese" and I can probably lift more and run further than most average people that are in the "healthy" range that haven't worked out a day in their life.

bcattoes

It isn't flawed; you're using it wrong. BMI is meant to track an average over a large population.

That is exactly the point though. People look at that as a guideline of where they should be, when in actuality it varies WIDELY by individual, and the guidelines it gives would be incredibly unhealthy for some people. Anything that considers the majority of body builders to be obese should probably not be used as a guideline when setting individual fitness goals.

It should not be your only tool, but bodybuilders are a minority. Minorities should not try to compare themselves to the majority. BMI is a valuable tool, when used with common sense.

From the CDC:

Why does CDC use BMI to measure overweight and obesity?
Calculating BMI is one of the best methods for population assessment of overweight and obesity. Because calculation requires only height and weight, it is inexpensive and easy to use for clinicians and for the general public. The use of BMI allows people to compare their own weight status to that of the general population.

Adding waist measurement to mix makes a big difference in the overall picture, but a surprising number of people refuse to be measured by their doctors.

Merithyn

Yes.
BMI stands for BODY MASS INDEX. What makes up mass? Fat AND muscle. If you're a body builder, you go off of BF%. If you are general population who does not exercise or maintain a healthy diet, BMI works just fine.
BMI is used in corporate wellness plans to track the general population of their employees b/c it is a more accurate standard to go by. There are some employees that are "outstanding" and go for doctor's review to be completely fair. These people are by far the minority.
I use BMI as a measure for employees every single day in my office and have not yet had to challenge a single employee's BMi because of fat vs. muscle mass.

Oddly, so do I, and I have to question it often. I work in medical health insurance with the uninsurable. Having a BMI >30 is an automatic denial for most insurance companies, regardless of BF%. I constantly get bombarded with doctors' notices that the person - despite an "unhealthy" BMI - has a healthy BF%.

I guess my anecdote cancels yours?

chivalryder

I find it interesting how people have been saying that it's designed for a large group of people, yet it is used on an individual basis...

Than other people are like "well, it's good for everyone , except for body builders and elite athletes!"

I haven't seen a single body builder on here, nor have I seen elite athletes.

So, again, are you calling me "average" and saying that I should be using it, when it's clearly not good for me? I'm sure I'm not the only person in this situation.

mscrumbyy

I try not to pay too much mind to BMI. When I was 16 I started trying to eat properly and I was already fairly active, and was aiming to me in the mid range of a healthy BMI like my doctor recommended. I made it, with a lot of hard work, and I looked awful. I looked ill, more than anything, and that was massively demotivating. So now my ultimate goal is in the higher end of healthy, if not a little extra. I'd rather not look as if I starved the weight off.

I used the Body Fat % Calculator on that site and I'm a little confused- according to that I'm already in the lower end of the acceptable range. Definitely not where I thought I would be.

Merithyn

I find it interesting how people have been saying that it's designed for a large group of people, yet it is used on an individual basis...

Than other people are like "well, it's good for everyone , except for body builders and elite athletes!"

I haven't seen a single body builder on here, nor have I seen elite athletes.

So, again, are you calling me "average" and saying that I should be using it, when it's clearly not good for me? I'm sure I'm not the only person in this situation.

I'm with you, to be honest, and no one would ever consider me an "elite athlete". For me to be on the very edge of a "healthy" BMI, I would have to weigh 135 pounds because I'm 5'2". However, I'm pretty muscular, always have been. (Built like a brick sh*thouse, as my dad used to say.) Not worth it to me to try to get down to that kind of healthy if it means losing muscle mass.

The BMI is NOT meant for the individual, and the sooner we stop using it as such, the better. Use Lean Muscle Mass. Use waist to hip ratio. Use BF%. But you're wasting your time with the BMI unless you are average in all ways, and who among us is?

bcattoes

I find it interesting how people have been saying that it's designed for a large group of people, yet it is used on an individual basis...

Than other people are like "well, it's good for everyone , except for body builders and elite athletes!"

I haven't seen a single body builder on here, nor have I seen elite athletes.

So, again, are you calling me "average" and saying that I should be using it, when it's clearly not good for me? I'm sure I'm not the only person in this situation.

I can't say with certainty if you are average or not. I would guess not, as most people don't ever know their BF% or strive for a certain BF% and most people with a high BMI also have a high BF%.

Should you use BMI? If you want, but not to the point of being detrimental to your health or goals. No chart or measurement should replace common sense.

jzrharv

BMI is a very crude and often misleading calculation. At my best physical condition, though not an "elite" athlete, when I was a Jazzercise instructor /runner in the latter part of the previous century (i.e. 1994), my "calculated" BMI was 29, borderline "obese". At that same time, I had my body fat tested, both with the infrared bicep method and the gold standard, underwater weighing. These results indicated a BF in the neighborhood of 14%. BMIs utility as an standard for individuals is pretty low, almost to the point of providing incorrect data for a person to assess their own fitness.

raeleek

I'm sorry but I'm going to have to disagree with the person above who said the bmi is not flawed. The bmi came to life in the 1850s as a study in social physics and somehow stuck. The JAMA and AMA are currently in the process of redoing the guidelines for healthy height to weight ratio because the top medical professionals and schools acknowledge how flawed it is. Also, think about the fact that the food pyramid has been modified multiple times over the years SO it stands to reason that the medical advances we've made since 1850 might actually dispel the 1850 bmi guide. If we're going to hold onto outdated medical information we might as well start handing out lead thermometers and lysol douches again.

taylor5877

At one point in my life I had a BMI of 30 and could see the veins in my obliques and lower abs.

Basically I would have had to lose 20 lbs of muscle to be "healthy".

Yet at that weight I'd have to jump thru hoops not to be paying too much for health insurance, life insurance, and to not be harassed by a blanket policy at my job (hypothetical here).

I'm not 210 now, but I'm also not really overweight at 5'10" 238 now (about 18 % body fat). I've set my "goal" at what I estimate will be my weight when I hit 10% body fat, which is fit by almost anyone's standard.

KiltFuPanda

I would recommend BMI to everyone as a "stage one" check - most people know their height and weight, so it's easy to punch that into the calculator. If you're at the 25 or above marker, this'll be your kick in the pants to check your stats a little closer.

So, what if you're thinking "I'm not so sure I'm overweight?" - Go to stage two.

The tape measurement bodyfat calculator would be a "stage two" check - where more of the semi-active to moderately active "overweight" people sit. This'll give you a closer view on how you're doing on a personal basis, and is accurate for a larger portion of the populace.

But there's a small portion of you that even the tape measurement will feel off for some reason. - Stage three for you!

This is calipers and professional analysis. Tape measurement only deals with proportions - hypertrophied muscle mass will skew the numbers. Sumo wrestlers, powerlifters, and other strength athletes tend to fall in here. Since this is taking measurements all around the body, it's taking more of you into consideration, and will give the most accurate reading.

I'll provide myself as an example.

6'3", 360 lbs, 52" waist.
Stage 1 - BMI = 45 - Stage 3 Obesity. Recommends I get professional help immediately.
Stage 2 - Tape Measurement = 34-35% - Still in the danger zone.
Stage 3 - Calipers = 24% - Borderline obese, but not as dangerous as above.

So, based on BMI, I should be dead. With tape measurement, I'm definitely in trouble. But with a more detailed examination, I'm unhealthy, but doing well enough to stay out of the hospital for now.

RuthieCass

At one point in my life I had a BMI of 30 and could see the veins in my obliques and lower abs.

Basically I would have had to lose 20 lbs of muscle to be "healthy".

Yet at that weight I'd have to jump thru hoops not to be paying too much for health insurance, life insurance, and to not be harassed by a blanket policy at my job (hypothetical here).

I'm not 210 now, but I'm also not really overweight at 5'10" 238 now (about 18 % body fat). I've set my "goal" at what I estimate will be my weight when I hit 10% body fat, which is fit by almost anyone's standard.

Are you sure you're 18%? Because you can take a look at the link below (note the 20% male) and see if you think you're actually near that range. It's hard to tell in your pic, but my guess is that you're underestimating your BF%.
http://www.leighpeele.com/body-fat-pictures-and-percentages

RuthieCass

I judge my UGW based on my current lean mass + a certain BF%. I was going by 15%, but decided that I should slow it down a bit and increased that number for a "One-step-at-a-time" goal. Once I've built up my fitness, then I'll aim for a lower BF%.

So I did the numbers. A healthy, relatively inactive male should have a BF% of 18-25%. 21% is half way in between, so I chose that as my goal.

I got the numbers from here: http://www.bmi-calculator.net/body-fat-calculator/body-fat-chart.php

I currently have a BF% of about 35%. At 223 lbs, that makes my lean mass around 144 lbs. Put on enough fat to make it 21% fat, and my UGW is 179 lbs.

Well, I'm 6' tall. I checked out the BMI scale, and at that weight, I will be hitting 24.27.

"Overweight" is higher than 24.9.

Now, here's the thing: If I put on 2 lbs of muscle before I reach my UGW, I'll be 185 lbs, which is considered "overweight," but it'll be less healthy for me to try to achieve a lower BF% so quickly!

I will ultimately aim for a BF% of 10-15%, but by that time, I'll have put on a lot more muscle, I will probably still be around 180lbs.

So, for those of you who believe that you need to have a low BMI in order to be healthy, or sexy/attractive, you may want to think again. The BMI scale is flawed.

Oh, and I should note: I could make my BMI lower, but I'd have to lose lean mass. For those who aren't in the "know," that would be a very, very bad idea. You want more lean mass, not less. Lean mass being your muscles, bones, and organs.

Edit: Added the link.

Sorry to be the bearer of bad news, but you are pretty much guaranteed too lose some LBM along with your fat. As you noted, LBM does not just include muscles; it also includes your organs, non-adipose connective tissue, etc. When you gain weight, many of your organs become enlarged (google some images-- e.g. heart of obese vs normal). And when you lose weight, organs will shrink as well. It is also easier to maintain a large amount of LBM when you carry around a lot of extra weight (ever notice an obese person's calf muscles?). Once you get down to 10%, you'll likely find that you'll have to do some bulking & cutting cycles to get your LBM back up to 144. Anyway, even in your example, you'd still fall in the normal BMI range, even if it is on the border. Generally, the more obese a person is, the less likely they will be able to retain all their LBM when they get down to a healthy weight.

That said, I agree with those that said BMI is a decent guideline for non-bodybuilders and non-athletes. The people I see often complaining about BMI do not have a lot of muscle (relative to overall weight) and have unhealthy amounts of BF. BF% can be a better measure than BMI, but the problem is that people cannot easily and accurately measure their BF%. For example, based on online calculators that use waist/hip/other measurements, my BF % is between 21-37%. If I wanted to be in denial, I could go by the 21% figure and claim to be really fit (not true, but I'm definitely not 37% either).

Thought this site was more interesting than many of those calculators:
http://www.leighpeele.com/body-fat-pictures-and-percentages