Why You Should NEVER Use BMI

chivalryder

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.

McLifterPants

Thanks for this! I am a 5'7" female, with a current BMI of 22.6 at 145 lbs. My lean mass is 112 lbs (22.2% body fat; "fitness" range for women). The BMI scale says that anything between 118 and 160 is healthy for someone my height and age. With 112 lbs of lean mass, if I got down to 118 lbs, my body fat percentage would be 5%. For a women, 10-12% is considered "essential fats," i.e. what you need to survive (athletes should have 14-20%). So 5% would be... well, dead. So yeah, according to the BMI scale, I'd be totally healthy if I were dead.

ElizabethRoad

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

McLifterPants

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.

ElizabethRoad

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.

chivalryder

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.

OK, so I made one error in the bottom of my post, stating that it was flawed. the rest of my post is valid. I see a lot of people on here who use it as a guideline on how heavy they should be.

mountainmare

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.

ElizabethRoad

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.

OK, so I made one error in the bottom of my post, stating that it was flawed. the rest of my post is valid. I see a lot of people on here who use it as a guideline on how heavy they should be.

I wasn't arguing with the rest of the post.

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.

That is true, but there are a decent number of people who are like me. Even at a healthy weight, I would be considered overweight, regardless of what I do. If I were to go by the BMI, I would be setting myself up with unhealthy and unrealistic goals.

BF% says a lot more about someone's health than the BMI chart does.

casperuk

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.

OK, so I made one error in the bottom of my post, stating that it was flawed. the rest of my post is valid. I see a lot of people on here who use it as a guideline on how heavy they should be.

You made another error by using such a sensational title.

Why you should NEVER use BMI

Never?
Never ever?
In any circumstance?
Or just you, and your body in your circumstances?

HisPathDaily

Exactly ... it's a good tool for an average individual who is just trying to stay healthy ... if your goal is muscle building and fine tuning, you have moved beyond a general tool like BMI. However I have seen plenty of people around me who are not exercising, overweight, and telling me that they are healthy because the BMI scale is a joke. Really? ... no.

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.

Merithyn

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.

BVannillie

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.

OK, so I made one error in the bottom of my post, stating that it was flawed. the rest of my post is valid. I see a lot of people on here who use it as a guideline on how heavy they should be.

You made another error by using such a sensational title.

Why you should NEVER use BMI

Never?
Never ever?
In any circumstance?
Or just you, and your body in your circumstances?

Agreed. I don't know what it is about some people on here who think me= everyone.

jdholland5508

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.

OK, so I made one error in the bottom of my post, stating that it was flawed. the rest of my post is valid. I see a lot of people on here who use it as a guideline on how heavy they should be.

You will be very suprised how much Lean Muscle you lose when you lose weight. It is very hard to drop 30+ lbs and keep all your lean body mass. I would exspect you to drop about 3-5 lbs from that number meaning you might want to readjust you calculations.

ErinBeth7

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 not in denial. I AM OVERWEIGHT. I am not big boned and nor do I think my frame is just "larger than normal."

I don't think that was what the OP was going for. I don't think he was trying to justify his weight because he couldn't face it. Like another poster said, he wasn't using the right tool.

buzzcogs

I think you are right. I think the BMI is pretty crap when it comes to males and may be too generous when it comes to females. At 5'5" when I was 150 my BMI was 25..right at overweight. I would consider that fair. If I stayed at 150 I might be considered slightly overweight but still healthy.
I do not think of a man who is 5'5" and 150 lbs as overweight at all! Women's and men's bodies differ so much in muscle mass, bone structure, and fat distribution I think it is pretty worthless to compare us with the same numbers.

susanswan

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.

This^^^^^^

MSepp

The body mass indicator is something I use for a certain population of individuals.

The very overweight and the very underweight.

The generally healthy range is >19 and <25...

HOWEVER, it should also take into account muscle mass and level of activity.

As a professional, the BMI is a good indicator of classes of obesity as well as malnourished/underweight populations.

if I have a patient that has a BMI of 26, but is generally healthy, gets exercise and eats a healthy diet, that person is not necessarily a nutritionally at risk or "overweight" person...maybe it's just their body type. It is useful for some things-not for most dieters unless you are in that obesity category (BMI >30)

Reesecup312

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.

This

Colbyandsage

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.

chivalryder

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.

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?