Is BMI really BS?

QueenBishOTUniverse

Overweight according to BMI



Do I still want to lose a few pounds, sure. Am I some sort of extreme athlete, nope, not really. Don't think I'm delusional about how fat I am, but who knows.

ETA: Oh and the calorie calculator on WebMD won't even give me a calorie goal for maintaining at my current weight because I'm unhealthy, it will only give me a goal if I want to lose weight, because even though the EXACT SAME calculator says that I'm healthy according to height and waist ratios, it ONLY uses BMI when generating a calorie goal. Just one more example of how stupidly BMI gets applied.

resistance_freak

ok, I have a couple of quick takes on this because it's something that I have thought a lot about in the past, and it's clearly caught a lot of attention on this thread now.

1st take: Is BMI really BS? Wow, this question encapsulates the thought that we live in a binary world where everything is either good or it's bad. Right or wrong, etc. BMI is a calculation using an individual's height and their weight. It's how someone interprets the result that could lead them to the conclusion that the number is "BS" But simply put, the higher the number, the more weight you carry for your height. It's about the most simplistic marker of where a person falls on some over vs. under-weight spectrum that you can get. So while I don't think it's an extremely USEful metric, I won't call it total BS either.

I've also read a few posts on this forum that indicate it's a good metric for evaluating a population's weight to height relationship (I'm paraphrasing here). And while I agree with this, that does not make the metric any more useful to most people. The only people that would use BMI to compare populations would be statisticians or researchers and I'd imagine that most people here don't fall into that category either (speaking of outliers)

2nd take: In addition to BMI there are a lot of other OBJECTIVE ways you can measure yourself and evaluate whether or not your body composition is where you want it to be. You can take simple circumference measurements of your waist, hips, chest, neck, arms, legs, etc. and then compare those over time to see where you're changing. If most of your increases are happening in your waist and hips then there might be a situation you need to take care of.

Alternative you can also have your bodyfat percentage measured, and there are a number of ways this can be done too, each with their own pros and cons and measurement issues, etc. which I won't go into detail about here because so many others have already done so. BUT! If you take multiple measurements of your bodyfat % and track that over time then you can get a pretty good idea if you're making good progress towards having the body composition that you want.

3rd take: Finally there are also SUBJECTIVE ways you can use to determine if you need to do some more work or not. Are your clothes fitting tighter or looser than they used to? Do you get winded doing things like climbing a flight of stairs that you could previously do with ease? Then there's always the eyeball test. Look in the mirror and be honest with yourself. Is that what you want to see looking back at you? And please, don't pick out this one sentence and tell me that my whole post is BS because some people don't see in the mirror what others see due to body dysmorphia or other similar situations. Clearly if someone suffers from that issue then the eyeball test isn't a good one for them.

Final take: I'm fine with using BMI as one measurement that gives you some information about where a person is with regards to their body composition. But when my health insurance company uses that number to tall me that I'm overweight and raises my premium because of it then THAT is when I have an issue. Not with the number, because it's not the number's fault. But with the policy of the insurance company to not look at other metrics to evaluate an individual's real risk of developing any number of health conditions due to carrying too much weight or too much fat. I understand this risk, but BMI alone is not the best way to evaluate this risk objectively and when it takes money out of my pocket I really dislike it even more.

SezxyStef

If estimations are correct I am 25% BF....

"Estimating" body fat is as much of a cardinal sin as estimating calories.

But the BMI chart is estimating your BF

Its using an average BF to determine if you are overweight or not - how is that in any way helpful?

Picking a point off of a empirically derived curve is more than just "estimating".

No it's worse! The BMI chart is using data from lots of different people to guess MY bodyfat and tell me if I'M overweight

Let's see, the empirical data curve for people who need glasses says that at 49 years old, I will need them. This rule will work for the majority of people, the majority of the time, therefore just like the BMI chart, it a great guide!

I said estimated due to the fact I have had no dexa scan for BF%...it's based on various sources but because it's not the gold standard I do call it an estimation.

My point is this...BMI should not alone be used to measure if someone is overweight/obese/healthy. BMI does not take into account the difference between LBM (which is not just muscle) and actual fat...and if the fat is viseral etc.

Niether should BF% or scale weight or even "personal opinion" of self.

Could I be lower in weight...sure could...do I want to be mid range BMI hell no...135...just doesn't work for me personally...I am guant thin and sickly looking ...hence why for me BMI alone is not a good measurment...

BMI+weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurment

Wonderob

My point is this...BMI should not alone be used to measure if someone is overweight/obese/healthy. BMI does not take into account the difference between LBM (which is not just muscle) and actual fat...and if the fat is viseral etc.

Niether should BF% or scale weight or even "personal opinion" of self.

Could I be lower in weight...sure could...do I want to be mid range BMI hell no...135...just doesn't work for me personally...I am guant thin and sickly looking ...hence why for me BMI alone is not a good measurment...

BMI+weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurment

Your list would be just as good, if not better if it was:
Weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurement

The BMI chart adds absolutely nothing to that list whatsoever

QueenBishOTUniverse

My point is this...BMI should not alone be used to measure if someone is overweight/obese/healthy. BMI does not take into account the difference between LBM (which is not just muscle) and actual fat...and if the fat is viseral etc.

Niether should BF% or scale weight or even "personal opinion" of self.

Could I be lower in weight...sure could...do I want to be mid range BMI hell no...135...just doesn't work for me personally...I am guant thin and sickly looking ...hence why for me BMI alone is not a good measurment...

BMI+weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurment

Your list would be just as good, if not better if it was:
Weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurement

The BMI chart adds absolutely nothing to that list whatsoever

Agreed, which is exactly why I don't use it.

Jennikitten

I think BMI should only ever be used in conjunction with common sense.

My BMI is 32.6 and I wear a size UK 14 (so about a US 12) someone I know has a BMI of 25.2 and wears a size UK 20/22.

I accept that I am over weight but obese? really? everybody is shocked when I tell them that I am classed as obese.

Wonderob

My point is this...BMI should not alone be used to measure if someone is overweight/obese/healthy. BMI does not take into account the difference between LBM (which is not just muscle) and actual fat...and if the fat is viseral etc.

Niether should BF% or scale weight or even "personal opinion" of self.

Could I be lower in weight...sure could...do I want to be mid range BMI hell no...135...just doesn't work for me personally...I am guant thin and sickly looking ...hence why for me BMI alone is not a good measurment...

BMI+weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurment

Your list would be just as good, if not better if it was:
Weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurement

The BMI chart adds absolutely nothing to that list whatsoever

Agreed, which is exactly why I don't use it.

Can't see why anyone would use the BMI chart over my new guide

Grab hold of stomach and wobble up and down - if it jiggles too much then you are overweight
Look down at your feet, if you can't see them you are obese
Try to put your socks on, if you can't then you're morbidly obese

For Christ sake don't rely on this guide though as even though it will be right for the majority of people, the majority of the time, it might not be for you so you need to see a doctor or find a more accurate way of measuring..... just like the BMI charts

McCloud33

Here's my problem with BMI. My "healthy" range would start at 7.5%BF for me! I'm 5'-8", 186 @ 17.5%BF as of this mornings weight in. This puts my lean body mass at around 153-154lbs. My "normal" range for BMI is 122-164. I honestly can not imagine 122 considering when I was in HS and skinny as a bean pole I still weighed 145+/-...and that was before I hit that second "puberty" where my shoulders got wider and got my "man strength" in my early 20's. 164 would be my floor not my ceiling for what I would consider normal for me. And before you say "oh well you're just an outlier", maybe I am, but before January of this year I've never lifted weights in my life and I haven't gained muscle mass since then either...I've actually lost about 9-10 lbs of it to go with all the fat weight I've dropped.

BMI is a statistic for statistically analyses of a *population*. It should not be used to assess the health of any one individual. I have no problem with it being used as an indicator, but I believe that it should only be used in conjunction with other metrics (ie. BF%, waist to hip ratio, frame size, family history) Using only BMI is lazy in my opinion. It's easy and you can train a monkey to weigh someone and measure their height.

majii13

BMI doesn't distinguish between fat and muscle so it's certainly massively flawed

Pick any muscly athlete and BMI will say they are overweight

eg. Running back Adrian Peterson



Not overweight surely? Well the BMI checker isn't ambiguous in any way: "Adrian Peterson BMI is overweight"

http://www.celebheightandweight.com/adrian-peterson-bmi-848.html

I know that doesn't really help you but quite interesting anyway???

I think my favorite outlier to the BMI scale is Kevin Durant. 6'9" tall, 235 pounds, BMI of 25.2, which is technically overweight.

The_GingerBeard_Man

I though you might find this useful.



The National Institutes of Heath did a study called: Accuracy of Body Mass Index to Diagnose Obesity In the US Adult Population

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2877506/

Wonderob

I though you might find this useful.



The National Institutes of Heath did a study called: Accuracy of Body Mass Index to Diagnose Obesity In the US Adult Population

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2877506/

Good article

Conclusion: "The diagnostic accuracy of BMI to diagnose obesity is limited, particularly for individuals in the intermediate BMI ranges"

So if you think you are overweight, take a look at the BMI chart. It might or might not be able to tell you, you won't know if it can or not though so for goodness sake don't rely on it for something as important as your flippin health!

QueenBishOTUniverse

I though you might find this useful.



The National Institutes of Heath did a study called: Accuracy of Body Mass Index to Diagnose Obesity In the US Adult Population

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2877506/

Dear lord those r-squared values, I also find the skew towards the bottom end of the BMI range on women interesting.

bennettinfinity

My point is this...BMI should not alone be used to measure if someone is overweight/obese/healthy. BMI does not take into account the difference between LBM (which is not just muscle) and actual fat...and if the fat is viseral etc.

Niether should BF% or scale weight or even "personal opinion" of self.

Could I be lower in weight...sure could...do I want to be mid range BMI hell no...135...just doesn't work for me personally...I am guant thin and sickly looking ...hence why for me BMI alone is not a good measurment...

BMI+weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurment

Your list would be just as good, if not better if it was:
Weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurement

The BMI chart adds absolutely nothing to that list whatsoever

LOL... that reminds me of the Pop Tart commercials from when I was a kid... they'd put the Pop Tarts next to some bacon, eggs, toast, and OJ and say 'part of this complete breakfast'... like the Pop Tarts added anything... it could've been a a shot of tequila and the same could be said... great... now I want tequila!

SezxyStef

My point is this...BMI should not alone be used to measure if someone is overweight/obese/healthy. BMI does not take into account the difference between LBM (which is not just muscle) and actual fat...and if the fat is viseral etc.

Niether should BF% or scale weight or even "personal opinion" of self.

Could I be lower in weight...sure could...do I want to be mid range BMI hell no...135...just doesn't work for me personally...I am guant thin and sickly looking ...hence why for me BMI alone is not a good measurment...

BMI+weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurment

Your list would be just as good, if not better if it was:
Weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurement

The BMI chart adds absolutely nothing to that list whatsoever

It does tho...what about those who are underweight per BMI...or those who are actually obese or morbidly obese...it adds another measure for them...it's when you get in the mid range I think it's bogus...the extremes still apply

Your way of measuring eh...you can have a jiggly stomach and not be over weight...just more BF% than you should have, I can jiggly my stomach...am I overweight nope...had a baby and was fat for over 20years...or viseral fat which is worse...

You would be hard pressed to jiggle my butt or legs tho...and forget about finding a lot of fat on my arms/shoulders and back...

and this guy who was not overweight could have jiggled his stomache a bit too..

http://www.express.co.uk/life-style/diets/451317/Olympic-gymnast-Louis-Smith-on-losing-weight-using-Tabata-interval-training

albayin

not really all bs IMHO, as a general guideline it makes sense to the majority of the population...People constanly use a few "outliers" (no offense to anyone I hope) as counter example...but seriouly...

Wonderob

My point is this...BMI should not alone be used to measure if someone is overweight/obese/healthy. BMI does not take into account the difference between LBM (which is not just muscle) and actual fat...and if the fat is viseral etc.

Niether should BF% or scale weight or even "personal opinion" of self.

Could I be lower in weight...sure could...do I want to be mid range BMI hell no...135...just doesn't work for me personally...I am guant thin and sickly looking ...hence why for me BMI alone is not a good measurment...

BMI+weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurment

Your list would be just as good, if not better if it was:
Weight+tape measurments+BF%+clothing size+health markers(BP etc)+ what I see in the mirror=a good measurement

The BMI chart adds absolutely nothing to that list whatsoever

It does tho...what about those who are underweight per BMI...or those who are actually obese or morbidly obese...it adds another measure for them...it's when you get in the mid range I think it's bogus...the extremes still apply

Your way of measuring eh...you can have a jiggly stomach and not be over weight...just more BF% than you should have, I can jiggly my stomach...am I overweight nope...had a baby and was fat for over 20years...or viseral fat which is worse...

You would be hard pressed to jiggle my butt or legs tho...and forget about finding a lot of fat on my arms/shoulders and back...

and this guy who was not overweight could have jiggled his stomache a bit too..

http://www.express.co.uk/life-style/diets/451317/Olympic-gymnast-Louis-Smith-on-losing-weight-using-Tabata-interval-training

Yep, just like BMI charts, my method does not work for everyone

"The extremes still apply" Yes, and if you're in the extremes you already know if you are very underweight or very overweight - again the BMI chart adds nothing

albayin

Do you think I should improve my BMI or is it all BS?

For the vast majority of people, the vast majority of the time, BMI is a pretty good rule of thumb. That's just reality.

You look great in the profile pic, but you also have room to lean out more, if that's your preference.

It's up to you! :drinker:

this ^^

I feel that sometimes some of us (including myself) can't face the harsh reality that we are over weight...trying to find justifications...

Wonderob

not really all bs IMHO, as a general guideline it makes sense to the majority of the population...People constanly use a few "outliers" (no offense to anyone I hope) as counter example...but seriouly...

But again, you don't know if you are one of the majority of the population for which it works

albayin

So 2 months ago I was considered "overweight"...sorry I have to laugh...at 160lbs..in a size 5/6...not overweight...

Clothing sizes is about the worse marker available when determining appropriate weight.

Almost all clothes in the US are vanity sized, and women's clothing has absolutely no regulations or standards. A 5/6 today can be so vanity sized that it was a 10-12, or higher, in decades past. Even men's clothes no longer follow the actual inches printed on the waist sizes. Hell I have two pairs of jeans from the 90s in a size 36 that are smaller than some size 33s today.

The mirror and your health markers are the best standard, clothing size the absolute worse.

BMI doesn't distinguish between fat and muscle so it's certainly massively flawed

Pick any muscly athlete and BMI will say they are overweight

eg. Running back Adrian Peterson

And yet how much of the general population has a body built like a professional running back?

Okay, but how am I supposed to know what to follow? My waist to hip ratio is excellent and my waist to height ratio implies I am too thin. So with all the "science" conflicting itself what now?

whatever makes you happy about your body, just follow that.

Grumpsandwich

I guess its good for a guideline but not a " Rule "

I was always self conscious of having a HIGH bmi even when i was teased for being a stick

Women in my family are built erm rather sturdy? lol wide round shoulders, large barrel built chest/rib cages, wide hips and large dense bones and naturally muscular ( gosh it sounds like im trying to sell a horse there :P lol)

I always used to be envious of tiny petite women with their size 0 pants! If I were a skeleton I would be lucky to fit an 8 hehe

albayin

not really all bs IMHO, as a general guideline it makes sense to the majority of the population...People constanly use a few "outliers" (no offense to anyone I hope) as counter example...but seriouly...

But again, you don't know if you are one of the majority of the population for which it works

Why do you want to argue about this? We are talking about if it's total BS, not if it's total BS in my case. right? So the answer is no, it's not total BS, and it's not total BS to me either.

QueenBishOTUniverse

not really all bs IMHO, as a general guideline it makes sense to the majority of the population...People constanly use a few "outliers" (no offense to anyone I hope) as counter example...but seriouly...

But again, you don't know if you are one of the majority of the population for which it works

Also, I'm seeing a lot more than a few outliers on those graphs, in BOTH directions, and since fat is what we're actually concerned about when it comes to health, those graphs tell me that BMI pretty much sucks at predicting how fat I actually am.

Wonderob

not really all bs IMHO, as a general guideline it makes sense to the majority of the population...People constanly use a few "outliers" (no offense to anyone I hope) as counter example...but seriouly...

But again, you don't know if you are one of the majority of the population for which it works

Why do you want to argue about this? We are talking about if it's total BS, not if it's total BS to ME. right? So the answer is no, it's not total BS, and it's not total BS to me either.

We are discussing whether or not the BMI chart is anyway useful

The OP is on the edge of healhy/overweight - Is the BMI chart of any use whatsoever to her? Not in the slightest

I can't see a single benefit in looking at the chart - it's totally useless if you only go by the criteria that the BMI chart uses

It's like saying to you, "I weigh 150lbs, am I overweight?" How could you possibly know based on that limited knowledge

YoungIronG

i am obese according to my BMI

my pants size is 36

albayin

just like any theory out there, it's all down to how you feel about it. If you believe it's BS, then just don't follow it. Simple as that.

Wonderob

Also, I'm seeing a lot more than a few outliers on those graphs, in BOTH directions, and since fat is what we're actually concerned about when it comes to health, those graphs tell me that BMI pretty much sucks at predicting how fat I actually am.

Yeah I'll add some more from the National centre for weight and wellness

Conclusions based only on this number can be misleading, especially when it comes to the following:
How muscular you are: A few people have high BMIs but don't have much body fat. Their muscle tissue pushes up their weight. An example: "A football player or a body builder who is very muscular. Their BMI shows up pretty high, and yet their body fat is actually pretty low,"

Your activity level: Someone who is very inactive may have a BMI in the normal range and have lots of body fat, though they may not look out of shape. "They have very low levels of muscle and bone -- often elderly people, those in poor shape, sometimes those who are sick. Their BMI can look in the normal range, even though they have quite a lot of body fat in comparison to their lean body mass,"
"Ultimately, they have similar risks as people who carry lots of body fat and have a high BMI."

Your body type: Are you an apple shape or a pear shape? The location of your fat makes a difference to your health. Generally, it's the abdominal fat, or the "apple" shape, that's metabolically riskier. When fat settles around the waist instead of the hips, the chance of heart disease and type 2 diabetes goes up. Fat that accumulates on the hips and thighs, or the "pear" shape, isn't as potentially harmful.

Your age: The notion of an ideal BMI may shift with age. "People who are older probably should have a little more fat on them, [but] they shouldn't have a BMI of 30," Atkinson says. He points out that late in life, people who are "a little bit overweight" tend to have a better survival rate than leaner people. The reasons for that aren't totally clear, but it may have to do with having reserves to draw upon when fighting off an illness. It's hard to tell for sure, since many factors affect your health.

Your ethnicity: Major ethnic differences exist regarding BMI. For example, Asian-Americans tend to develop health risks, including the risk of diabetes, at significantly lower BMIs than whites. A healthy BMI for Asians ranges from 18.5 to 23.9, a full point lower than the standard range. More strikingly, Asians are considered obese at a BMI of 27 or higher compared, to the standard BMI obesity measure of 30 or higher.

csuhar

I can agree with this to some extent. The only problem is body shape. It doesn't take into account anything other than numbers.

What does body shape have to do with BMI or body weight?

Well, there's the issue that humans aren't diverse in terms of body structure with regards only to height. We also vary in regard to how wide and deep our skeletal structure is.

My brother, for example, is only an inch shorter than me, but can hide behind me because I have a broader build. That increased size from side-to-side is going to add weight. My brother's feet are somewhere like a US size 10.5. My feet are a US size 15. I don't know exactly what his head size is, but I do know he readily finds hats in his size while I have to find the biggest hats a company makes and even then they don't always fit on my size 8 cranium.

As a result, all those dimensions where I'm larger than my brother- height, breadth, foot size, head size, etc are increases in size that are also going to add weight, even if we actually have the same amount of fat on our bodies. But all the BMI sees is the difference between my brother being 6'1" and me being 6'2".

That's why the BMI is **GENERALLY** useful, but it's not really going to give you a detailed, personalized result you may want to work with.

SnicciFit

No, it's not BS. BMI is a generalization that will work for generally most people. It's become very common these days to attack BMI due to the outliers who have a higher than typical muscle mass, and thus for whom BMI is of little use. However the vast majority of people aren't rocking the amount of additional lean mass needed to skew the BMI radically.

The heart of the matter, for many, is that they hate that BMI tells them they're still too fat. A lot of people have come to loathe the old height/weight chart ranges and BMI because they point to the fact that we've, on the whole, lost perspective of just how small most people need to be in order to not be overweight. Especially here in the US we've become very, very skewed about appropriate weight and BMI.

As far as your own personal goals, are your health markers good? When looking in the mirror do you have excess fat that you're unhappy with? When you say you "dislike" your body, what exactly do you dislike? That there is still too much fat mass or are you talking about other parts that are unchangeable (naturally speaking)?

BMI knows nothing about how fat you are. Only what your height to weight ratio is. There is nothing in the BMI calculation that determines if you carry a lot of fat or not. Yes, in my opinion, it's mostly BS.

Wonderob

just like any theory out there, it's all down to how you feel about it. If you believe it's BS, then just don't follow it. Simple as that.

Eh? It WAS promoted by governments and advisers as being the way to judge whether of not you are healthy. That's pretty important!

Doctors and governments in the 1920s used to promote cigarettes as being good for your health.
Are you suggesting that people shouldn't challenge this, and instead just say "Oh well, if you didn't believe them you should just ignore this claim and call it BS?

QueenBishOTUniverse

just like any theory out there, it's all down to how you feel about it. If you believe it's BS, then just don't follow it. Simple as that.

Eh? It WAS promoted by governments and advisers as being the way to judge whether of not you are healthy. That's pretty important!

Doctors and governments in the 1920s used to promote cigarettes as being good for your health.
Are you suggesting that people shouldn't challenge this, and instead just say "Oh well, if you didn't believe them you should just ignore this claim and call it BS?

And there's the rub. I'm trained in science, I can look at those graphs and see that the actual predictive value of BMI for telling me if I'm too fat or not is practically nil. The average person doesn't have a clue about this, they go to a doctor's office or on to a site like WebMD, look at the chart and say oh, well according to this I'm healthy. Well no actually, the bmi chart can't tell you that AT ALL but most people won't investigate any further than that one basic step.