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How do we judge a healthy weight range? BMI is no longer valid?
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guideline only. Says Im overweight the BMI scale can kiss my A**0
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I didn't read all 4 pages but my question would be Who is doing the determining?
For my personal happiness I could give a fat damn about BMI? Do I feel good? Do I think I look good? Well, that's good enough for me. Especially since all those studies came out last year stating that people who are overweight have the same life expectancy and quality of life as those with normal BMI. I can't find the study itself but here is an article in the Times about it.
http://www.nytimes.com/2013/01/02/health/study-suggests-lower-death-risk-for-the-overweight.html?_r=0
Anyway, now if it's being used by some actuary to determine my insurance costs, that's a totally different thing and yes...BMI is wrong...please cut me some slack.
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just my 2 cents worth here, I believe that while BMI can be a useful tool in determining a healthy weight, it is not the only tool that can be used. Personally, I track a variety of things to tell me how I'm doing, including my BMI, my waist to hip ratio, my waist to height ratio, and a rough estimate of my BF% (figured out from an average of 3 different online calculators and a set of calipers that I own) to figure out my healthy weight range. BMI in my opinion is a good starting point for those who aren't as familiar with different ways of measuring their progress.
Yes, anyone who is serious about changing their body has very likely used many more measurements than just BMI. As has been stated here many times, it's a fantastic starting indicator, but should be used alongside things such as bodyfat, tape measurements, etc. That being said, statisticians (what BMI is really good for) don't exactly have the time to roll around popping tapes, pinching skinfolds, and asking for DEXA results on every third member of the population.
As for the rest of the thread's argument: if the world had as many heavily muscled individuals with sub 12% bodyfat as it does landwhales who are pushing 35%, I would agree that BMI is useless. Take a good hard look around though, tell me that BMI is useless for the population at large, and I'll conclude that you're either blind, or have fallen into the cognitive dissonance trap.14 -
Mouse_Potato wrote: »MarkusDarwath wrote: »And I have always been told that bio-electrical impedance is at best only good to evaluate whether your BF% is trending up or down, not to get an accurate number.
This is true, and yet it's still more accurate than BMI.
Or if you don't trust BIA there are a myriad of other formulas more accurate than BMI where you can take some measurements and type them into a web site. Height to waist ratio, and the formulas the military branches use when BMI fails and they "go to the tape" both come to mind.
I find it interesting that you bring up the height to waist ratio. I am about 5'3.5" so my healthy waist measurement is under 32". However, at 140 pounds (24.4 BMI) my waist was just over that measurement indicating that I was overfat even though BMI had me at the high end of "normal weight." I don't know if I was actually at an unhealthy weight or not. My torso is very short, so my waist will never be tiny.
TL;DR The height to waist ratio measurement is even less forgiving than BMI for some of us.
This is actually more common than the other way around. It's easier and more likely to be overfat without being overweight, than to be overweight without being overfat.
This page quantifies that:
"Our results suggest that 17.3% of women and 31.6% of men who were identified as obese according to BMI were misclassified according to sex-and-age-specific %BF criteria. The inability to distinguish the different contributions to body weight, of fat and non-fat tissue (such as muscle and bone, which have greater densities than fat), explains why the BMI might overestimate adiposity in muscular and lean body builds.
On the other hand, only 80.1% of women and 53.9% of men in our study who were classified as obese using sex-and-age-specific %BF thresholds had BMI in the obese range (my note: this was defined as around 29% bodyfat for men, around 44% for women). As a corollary, 19.9% of women and 46.1% men with high %BF were overlooked as being obese according to BMI criteria."
and:
"Using sex-and-age-specific cut-points for %BF equivalent to BMI 30.0 kg/m2, we report that 24.7% (95% CI 22.2, 27.1) of men and 29.5% (95% CI 26.7, 32.3) of women were obese. The prevalence estimate for men was greater than the estimate of 19.7% (95% CI 17.5, 21.9), which was based on BMI criteria. The pattern was similar for women for whom the prevalence of obesity according to the BMI was 28.2% (95% CI 25.4, 31.0)"
So it's like one of those Venn diagrams with overlapping circles. Overweight is one circle, overfat is another circle. For women, they overlap 75% of the time, for men they overlap about 65%, but in both groups, the BMI misses obesity more often than it incorrectly labels someone obese.
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Gallowmere1984 wrote: »just my 2 cents worth here, I believe that while BMI can be a useful tool in determining a healthy weight, it is not the only tool that can be used. Personally, I track a variety of things to tell me how I'm doing, including my BMI, my waist to hip ratio, my waist to height ratio, and a rough estimate of my BF% (figured out from an average of 3 different online calculators and a set of calipers that I own) to figure out my healthy weight range. BMI in my opinion is a good starting point for those who aren't as familiar with different ways of measuring their progress.
Yes, anyone who is serious about changing their body has very likely used many more measurements than just BMI. As has been stated here many times, it's a fantastic starting indicator, but should be used alongside things such as bodyfat, tape measurements, etc. That being said, statisticians (what BMI is really good for) don't exactly have the time to roll around popping tapes, pinching skinfolds, and asking for DEXA results on every third member of the population.
As for the rest of the thread's argument: if the world had as many heavily muscled individuals with sub 12% bodyfat as it does landwhales who are pushing 35%, I would agree that BMI is useless. Take a good hard look around though, tell me that BMI is useless for the population at large, and I'll conclude that you're either blind, or have fallen into the cognitive dissonance trap.
I think this is exactly the point of contention - BMI is a great metric for studying populations - in fact, that's exactly why it was created - but it's not so great when applied to individuals; for a multitude of reasons.
Per your example above, you could have two individuals of identical height and weight; one at 12% BF another at 35%... both would be classified as 'Obese'... the inability to distinguish between two radically different individuals is the hallmark of a weak metric.1 -
Packerjohn wrote: »MarkusDarwath wrote: »Packerjohn wrote: »MarkusDarwath wrote: »One caveat about the thing with the belt, it can depend on how you wear your pants. The waist measurement for assessing body composition is supposed to be taken around the navel, whereas most men wear the 'waist' of their pants more toward the top of the hips. I wear size 36 pants, but my actual waist measurement is 47.5. Fortunately, my belly distension is not flabby, or I'd be sporting a major 'dunlap' aside from just being round.
Sorry, as has been mentioned before you are wearing size 36 pants because you have a large amount of visceral fat. The location of the fat forces your pants to fit that way. Most men don't wear a pants size 12 inches less than their waist size.
I never claimed I didn't. I was merely pointing out that using your belt size as an indicator is not going to be accurate if your belly is larger than your belt. If I assessed myself based on my pants size, it would suggest I'm in pretty decent shape, which clearly is not the case.
None of the measurements that use a ratio use belt size as a factor. They use waist measuremnt at the natural waist (you can Google and find where that is) vs height ot hips measurement.
I know that. My original response was to the fellow who said he kept track by marking measurements on the inside of his belt. As long as one's belly is the same size as where there belt rides, that works, but in a case like mine it would not.
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Serious question, does the heart care if it's muscle or fat? I mean, take Rich Piana or someone who is packing 300+ of lean mass... Does the heart care?2
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Gallowmere1984 wrote: »As for the rest of the thread's argument: if the world had as many heavily muscled individuals with sub 12% bodyfat as it does landwhales who are pushing 35%, I would agree that BMI is useless. Take a good hard look around though, tell me that BMI is useless for the population at large, and I'll conclude that you're either blind, or have fallen into the cognitive dissonance trap.
Again, the thread was about how to determine what should be a healthy weight. On an individual basis, BMI is useless for that. The weight ranges are too broad to be of help to someone just getting started into improving fitness, and there are far too many people who will simply fall outside the scale (either high or low) once they get down to a healthy body fat percentage.
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Serious question, does the heart care if it's muscle or fat? I mean, take Rich Piana or someone who is packing 300+ of lean mass... Does the heart care?
I would speculate, no. At least not directly. Where the danger to the heart comes in is from the metabolic changes created by too much visceral fat in and around the other organs.
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Serious question, does the heart care if it's muscle or fat? I mean, take Rich Piana or someone who is packing 300+ of lean mass... Does the heart care?
Would be intersted in the input from someone with a medical background.
The muscular 300 pound person had to do a lot of hard work to get there. That work would involve stressing the heart, which as a muscle would grow stronger as it is worked.
Given that it's stronger I would think it is working with much less effort when the 300 pound muscular dude is doing daily tasks as opposed to a 300 pound person with 35%+ bodyfat.1 -
Mouse_Potato wrote: »MarkusDarwath wrote: »And I have always been told that bio-electrical impedance is at best only good to evaluate whether your BF% is trending up or down, not to get an accurate number.
This is true, and yet it's still more accurate than BMI.
Or if you don't trust BIA there are a myriad of other formulas more accurate than BMI where you can take some measurements and type them into a web site. Height to waist ratio, and the formulas the military branches use when BMI fails and they "go to the tape" both come to mind.
I find it interesting that you bring up the height to waist ratio. I am about 5'3.5" so my healthy waist measurement is under 32". However, at 140 pounds (24.4 BMI) my waist was just over that measurement indicating that I was overfat even though BMI had me at the high end of "normal weight." I don't know if I was actually at an unhealthy weight or not. My torso is very short, so my waist will never be tiny.
TL;DR The height to waist ratio measurement is even less forgiving than BMI for some of us.
I have the same build. At 25 BMI my waist was on the edge. My DEXA indicated that my BF% actually was okay, and I did not have an issue with visceral fat as I'd feared as I tend to be an apple. It's just that my hipbones are high because my torso is short, legs are long (for someone 5'3) and that throws off the waist measurement.
All that aside, BMI works well for me, and the vast majority of women. I think a higher percentage of men may be overweight BMI and yet fine to good BF%, but they likely can figure that out, as they will have more muscle than average and a mirror will help (as do photos, measurements, and an objective other person).1 -
MarkusDarwath wrote: »middlehaitch wrote: »MarkusDarwath wrote: »One caveat about the thing with the belt, it can depend on how you wear your pants. The waist measurement for assessing body composition is supposed to be taken around the navel, whereas most men wear the 'waist' of their pants more toward the top of the hips. I wear size 36 pants, but my actual waist measurement is 47.5. Fortunately, my belly distension is not flabby, or I'd be sporting a major 'dunlap' aside from just being round.
So basically what you are saying is- you are obese with an unhealthy amount of visceral fat and you have problems with your BMI.
I'm saying I am obese and working on it, and BMI is completely irrelevant. Body Fat Percentage is a useful tool.
I agree, BF% done accurately is more useful than BMI. But every measure that has been mentioned in this thread, BF%, waist/hip ratio, waist/height ratio, your current measurements put you at obese (but working on it). BMI gives the same result, how is it irrelevant for you at this point as well as 85% or so of the population? It gives the same answer.
When you get down to 220 and 15% BF, then you may very well be one of the 15% or so of the population where it isn't relevant/reliable.3 -
MarkusDarwath wrote: »Gallowmere1984 wrote: »As for the rest of the thread's argument: if the world had as many heavily muscled individuals with sub 12% bodyfat as it does landwhales who are pushing 35%, I would agree that BMI is useless. Take a good hard look around though, tell me that BMI is useless for the population at large, and I'll conclude that you're either blind, or have fallen into the cognitive dissonance trap.
Again, the thread was about how to determine what should be a healthy weight. On an individual basis, BMI is useless for that. The weight ranges are too broad to be of help to someone just getting started into improving fitness, and there are far too many people who will simply fall outside the scale (either high or low) once they get down to a healthy body fat percentage.
If someone just getting started is 300 pounds and the BMI says they should be 150-175, don't you think somewhere in that range is a better long term goal than pulling something out of the air?
Sure by the time they get to 190 or so they may decide they are super jacked, 10% BF and it would be stupid to get down to 175. That is fine. The BMI measure gives them a reasonable direction to the ballpark, not to seat 15 row 20 of the left field bleachers.10 -
I doubt any of us are here because our BMI's are 27 instead of 21. Use it as one input. Your eyes and your heart and your sports performance and your overall health are the best metrics when you get close.
I am. BMI 27.5 when I started out. I was beginning to look far too matronly. Now down to 25.4 and still look visibly fat. I look best around 22.5 - I sag too much, below that and find it hard to retain muscle tone, as I'm hypermobile.
Giveaways not dependent on muscle mass are things like hands and faces. Overweight people might have fairly slim faces, but it's very rare that an adult with a chubby face is a healthy weight. There is no amount of pretending that cheek fat and neck rolls are down to being a supper ripped BMI outlier. (Though no doubt that's a big vegan conspiracy, too)5 -
Oh, and just in case it's not been spelled out clearly enough, BMI is a range, precisely to account for different builds. Unless your name is Gimli, 25 probably is really the top end for you.2
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The athlete in question might be Mo Farah. He has long limbs. Still extremely muscular. Carrying an extra 60lb for 26 miles isn't very efficient, so it wouldn't benefit him to be any bigger.thetimes.co.uk/tto/multimedia/archive/00859/173133512__02_859583c.jpg0
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Packerjohn wrote: »If someone just getting started is 300 pounds and the BMI says they should be 150-175, don't you think somewhere in that range is a better long term goal than pulling something out of the air?
I think they should measure or calculate their body fat percentage, use that to determine lean mass, and pick a BFP within normal range to shoot for, adding that number back to their lean mass.
Yes, they might likely lose some lean mass along the way and need to recalculate, but chances are the initial target is going to be less daunting than right off the bat deciding they have to lose half of themselves. They would at least be using solid personal numbers instead of a generic guesstimation.
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MarkusDarwath wrote: »Packerjohn wrote: »If someone just getting started is 300 pounds and the BMI says they should be 150-175, don't you think somewhere in that range is a better long term goal than pulling something out of the air?
I think they should measure or calculate their body fat percentage, use that to determine lean mass, and pick a BFP within normal range to shoot for, adding that number back to their lean mass.
Yes, they might likely lose some lean mass along the way and need to recalculate, but chances are the initial target is going to be less daunting than right off the bat deciding they have to lose half of themselves. They would at least be using solid personal numbers instead of a generic guesstimation.
What about those without the ability to measure BF%?1 -
MarkusDarwath wrote: »Packerjohn wrote: »If someone just getting started is 300 pounds and the BMI says they should be 150-175, don't you think somewhere in that range is a better long term goal than pulling something out of the air?
I think they should measure or calculate their body fat percentage, use that to determine lean mass, and pick a BFP within normal range to shoot for, adding that number back to their lean mass.
Yes, they might likely lose some lean mass along the way and need to recalculate, but chances are the initial target is going to be less daunting than right off the bat deciding they have to lose half of themselves. They would at least be using solid personal numbers instead of a generic guesstimation.
Unless they're paying for a DEXA scan, though, or maybe a BodPod, the reality is that most methods of measuring body fat % have such a large margin of error that they are probably even less reliable than BMI as a tool to calculate goals from.9 -
Oh, and just in case it's not been spelled out clearly enough, BMI is a range, precisely to account for different builds. Unless your name is Gimli, 25 probably is really the top end for you.
At 6'1", 220 pounds and 15% body fat, 40% of my mass would be muscle, which is actually in the bottom half of average according to reference.com.
https://reference.com/science/percentage-body-weight-muscle-9342f11bfa8a2895#
Yet these same stats calculate to a 29 BMI. I am not Gimli. I'm simply a tall guy with broad shoulders, not terribly unusual at all, especially here in the mid-west. So how would a normal person with normal fat and muscle percentages end up on the verge of "obese" unless the metric is wrong? The only way I could remotely be an outlier is if my bones and organs are unusually heavy, and I don't buy that at all.
To get under 25 BMI I would need to get down to 185. Crunching some more numbers, I can determine the non-muscle portion of my lean mass. This number flat out should not change, no matter what I weigh. If I subtract that number from 185, and then subtract the weight of 15% body fat, the remaining muscle weight comes out to roughly 34% of total mass. This is below average for men. And the BMI for this is still almost 10 points higher than actual body fat percentage.
My conclusion, based on simple numbers, is that the BMI charts promote sub-average musculature as "healthy", at least for tall men. It may well go the other way for short people.
But this promotion of sub-average musculature is why I suspect the research behind the establishment of the guidelines may have been skewed by vegan social bias. Scientists, doctors, etc. are human just like the rest of us. They are not gods of detachment with a magical ability to remove their personal prejudices from their work, any more than anyone else is. And group-think is always a very strong force within any large institutional organization.
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