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Is every single body in the world intended to be within the so-called healthy BMI range?

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Replies

  • jdlobb
    jdlobb Posts: 1,232 Member
    jdlobb wrote: »
    f-it, heres for men and women, the whole table 4, with Ideal Weight percentages calculated.

    BMI is more forgiving than BF% for both men and women for the majority of age groups

    pgf8g71y283l.jpg

    I wonder if the fact that the only age groups for which BF% seems to be more permissive than BMI for both genders is "middle age" (40-70) contributes to why so many people here in particular think BMI shouldn't apply. An interesting observation to be sure.
  • jdlobb
    jdlobb Posts: 1,232 Member
    edited November 2017
    Hopefully my parting thought in this thread unless somebody drags me back in with some nonsense.

    This paper addresses something that isn't talked about enough, and it often used inadvertently as an excuse.
    Furthermore, accumulation of body fat in healthy bodies is generally accompanied by a compensatory response from the musculoskeletal system, acting through mechanoreceptors in muscle and bone, as it adapts to better cope with the increasing mechanical load [19]. Adipokines also act as regulatory messengers between adipocytes in fat deposits, muscle [20] and bone [21, 22]. However, with excessive accumulation of body fat, the increased loading could exceed compensatory musculoskeletal responses thereby altering the proportions of fat, lean and bone issue. As a consequence, increases in BMI could reflect increased weight-for-height yet mask changes in body composition. Considering the obesity epidemic, a more accurate indicator of body fatness is required to better assess obesity-related health risks.

    Somebody who is obese, particularly somebody who's been obese for a significant amount of time, will have a much higher LBM than they would if they were thin. This may lead them to believe that they don't "fit the BMI model" because the have too much muscle and bone. But this would be false. If they were to lose the fat, they would also very likely loose a significant amount of that additional muscle, and even some of the bone mass eventually. Pulling them back into the normal BMI range. If however they engage in rigourous weight training in order to keep that muscle mass, thus keeping them above the normal BMI range at a healthy BF%, they would be no different than a strength athlete that is a BMI outlier because they train for muscle mass. Additional work, above and beyond what is normal, was put in with the specific goal of maximizing muscle mass.

    So thank you for posting this paper, as I think it provides a good deal of evidence to support the idea that under normal circumstances every body (in a statistical sense) should be able to fit into the normal weight BMI range, baring exceptions for disease, injury, or exceptional effort to build or reduce muscle mass outside the normal range.
  • lemurcat12
    lemurcat12 Posts: 30,886 Member
    jdlobb wrote: »
    I'm not saying this is not true, it is obviously true.

    Okay, good. I had understood you as claiming it was not, or so rarely as to be irrelevant.

    That's really the only point I am interested in.
    What I am pointing out is that

    1. the paper does not contain the relevant data to know how many people meet this criteria

    I think that's probably true, although I have not tried to go through the tables sufficiently to know for sure. What I have found, in looking at a variety of such papers, is that researchers seem much more interested in how useful BMI is in identifying who is obese, probably because for health purposes that is what really matters.

    However, what we do know is that 75% of women and under 67% of men are in the right categories, and how those categories break down for the obese -- substantially more people are obese by BF% in the younger categories than by BMI, but for women it's something like 17% categorized obese by BMI who are really overweight vs. 19% the other way around, and for men 30-something vs. 40-something. I think the numbers suggest that's a likely pattern for "ideal weight"/overweight too, which would indeed mean that a substantial number were miscategorized in both ways. But I have not claimed the study was definitive on this specific point, as that's neither why I posted it nor my (later) problem with what you seemed to be saying.

    Again, I posted it because although I had known BF% showed that SOME men were miscategorized as obese who were not and some of both sexes were miscategorized as not obese who were, I was surprised the numbers were as high as they were, especially in the first category.
    3. given that the number of ideal weight people falls, in some cases considerably, when moving from BMI to BF% it is quite reasonable to assume that the number of overweight people who are ideal weight under BF% is likely quite low, and almost certainly far less than 20%.

    No, it's not. Again, the obese percentage falls too, when moving from BF% to BMI, and yet we know that more than 20% of men are miscategorized both ways, and approximately 20% (a bit less) of women.
    The paper is arguing, quite effectively, the BMI is an ineffective tool because it is most likely to UNDERESTIMATE how fat somebody it.

    Yes, that it part of it, but the bigger issue is it does both.

    And again, everyone knows there are issues in both directions, I and others said this way, way, way upthread and I made that clear when posting the study.
  • lemurcat12
    lemurcat12 Posts: 30,886 Member
    edited November 2017
    jdlobb wrote: »
    Hopefully my parting thought in this thread unless somebody drags me back in with some nonsense.

    This paper addresses something that isn't talked about enough, and it often used inadvertently as an excuse.
    Furthermore, accumulation of body fat in healthy bodies is generally accompanied by a compensatory response from the musculoskeletal system, acting through mechanoreceptors in muscle and bone, as it adapts to better cope with the increasing mechanical load [19]. Adipokines also act as regulatory messengers between adipocytes in fat deposits, muscle [20] and bone [21, 22]. However, with excessive accumulation of body fat, the increased loading could exceed compensatory musculoskeletal responses thereby altering the proportions of fat, lean and bone issue. As a consequence, increases in BMI could reflect increased weight-for-height yet mask changes in body composition. Considering the obesity epidemic, a more accurate indicator of body fatness is required to better assess obesity-related health risks.

    Somebody who is obese, particularly somebody who's been obese for a significant amount of time, will have a much higher LBM than they would if they were thin. This may lead them to believe that they don't "fit the BMI model" because the have too much muscle and bone. But this would be false. If they were to lose the fat, they would also very likely loose a significant amount of that additional muscle, and even some of the bone mass eventually. Pulling them back into the normal BMI range. If however they engage in rigourous weight training in order to keep that muscle mass, thus keeping them above the normal BMI range at a healthy BF%, they would be no different than a strength athlete that is a BMI outlier because they train for muscle mass. Additional work, above and beyond what is normal, was put in with the specific goal of maximizing muscle mass.

    So thank you for posting this paper, as I think it provides a good deal of evidence to support the idea that under normal circumstances every body (in a statistical sense) should be able to fit into the normal weight BMI range, baring exceptions for disease, injury, or exceptional effort to build or reduce muscle mass outside the normal range.

    (1) I'm finding it very rude and disingenuous that you keep trying to suggest that I did not realize the study said that there were misclassifications both ways. This is exactly what I said when posting the study:

    "Here's one good comparison of BF% and BMI (given that the purpose of BMI is to act as a proxy for BF%): https://bmcobes.biomedcentral.com/articles/10.1186/2052-9538-1-9

    Key findings (note, this is for white people in Australia, there are likely race-based differences):

    *17.3% of women and 31.6% of men identified as obese according to BMI were not, based on BF%.
    *19.9% of women and 46.1% of men who were NOT obese by BMI actually were by BF%

    *BMI particularly underestimates adiposity in elderly men (aged 70 years and older), but also in young men (aged 20–29 years).

    That's different from another such study I recall seeing in the past, where it was much more likely to mischaracterize women as not obese when they were than obese when they were not. There was more mischaracterization for the overweight category in that one (this one focused on obesity measures only)."

    (2) I think you are correct on the limited (but irrelevant) point that most everyone COULD fit into a healthy BMI range. However, that does not mean that it's HEALTHIER to do so or that everyone SHOULD. It's clear there's a significant number of people who can be classified as overweight due in part to more than average muscle mass while being lean. Leanness is what matters (I currently believe, although if you think that's wrong, post something). If I were 20% BF (which is fine, quite lean even, for a woman) and 145 lb (overweight BMI) and 116 lean mass, I'd be totally fine and healthy. That's generally unlikely for me, but not impossible for someone of my size. It would take work.

    If someone is both extra muscle-y due to building muscle during years of being overly heavy AND manages to lose the fat without losing all of the excess lean mass, due to protein + progressive weight training + good genes, that's probably a good thing, not a bad one.

    I had a DEXA because I was curious about muscle mass, but also because I was curious about bone density. My bone density is great for my age. It's quite possible that's in part because I was overweight for a time (not saying it makes a difference to my appropriate BMI range), but that it was caused by being fat doesn't make it bad. Same with excess muscle mass.
  • jdlobb
    jdlobb Posts: 1,232 Member
    lemurcat12 wrote: »
    jdlobb wrote: »
    I'm not saying this is not true, it is obviously true.

    Okay, good. I had understood you as claiming it was not, or so rarely as to be irrelevant.

    That's really the only point I am interested in.
    What I am pointing out is that

    1. the paper does not contain the relevant data to know how many people meet this criteria

    I think that's probably true, although I have not tried to go through the tables sufficiently to know for sure. What I have found, in looking at a variety of such papers, is that researchers seem much more interested in how useful BMI is in identifying who is obese, probably because for health purposes that is what really matters.

    However, what we do know is that 75% of women and under 67% of men are in the right categories, and how those categories break down for the obese -- substantially more people are obese by BF% in the younger categories than by BMI, but for women it's something like 17% categorized obese by BMI who are really overweight vs. 19% the other way around, and for men 30-something vs. 40-something. I think the numbers suggest that's a likely pattern for "ideal weight"/overweight too, which would indeed mean that a substantial number were miscategorized in both ways. But I have not claimed the study was definitive on this specific point, as that's neither why I posted it nor my (later) problem with what you seemed to be saying.

    Again, I posted it because although I had known BF% showed that SOME men were miscategorized as obese who were not and some of both sexes were miscategorized as not obese who were, I was surprised the numbers were as high as they were, especially in the first category.
    3. given that the number of ideal weight people falls, in some cases considerably, when moving from BMI to BF% it is quite reasonable to assume that the number of overweight people who are ideal weight under BF% is likely quite low, and almost certainly far less than 20%.

    No, it's not. Again, the obese percentage falls too, when moving from BF% to BMI, and yet we know that more than 20% of men are miscategorized both ways, and approximately 20% (a bit less) of women.
    The paper is arguing, quite effectively, the BMI is an ineffective tool because it is most likely to UNDERESTIMATE how fat somebody it.

    Yes, that it part of it, but the bigger issue is it does both.

    And again, everyone knows there are issues in both directions, I and others said this way, way, way upthread and I made that clear when posting the study.


    Yes. Obese does fall. However, "overweight" increases by a greater amount that "Obese" falls. This leads to the conclusion that a greater number of both overweight and ideal weight people by BMI are in fact "overweight" by BF%.

    There is nothing here to suggest that the ideal weight/overweight boundary is as erroneous or equally porous as the overweight/obese boundary. There is nothing in this study that would preclude that either.

    As I have pointed out repeatedly, the data that stanman claimed was here when he replied to me and started this debate, simply does not exist in this study.

    The study only contains data on the error in the overweight/obese boundary, as in public health research this is the only one that particularly matters.

    Any assumptions you make about the healthy/overweight boundary is entirely and completely supposition, not based on any of the data in this report, at all.

    The closest we can get is look at the % incorrect at the overweight/obese boundary and compare it to the overall incorrect ratio. Both of which are known. But as we can see, the percentage miscategorized at that boundary is higher than the miscategorized percentage for the whole population, meaning they make up a disproportionate number of all those miscategorized. For women the percentage is closer. The population suggests that 73.9% of women are correctly categorized, but only 62.8% of overweight or obese women are.

    For men it's enormous though. The population would suggest that 62.6% of men are correctly categorized, but among overweight and obese men only 22.3% are. Meaning that nearly ALL of the miscategorized men are at the overweight/obese boundary.

  • jdlobb
    jdlobb Posts: 1,232 Member
    Numbers confirmed, actually over confirmed. The writers apparently made adjustments in the background to account for differences in population sizes, but the final paper only contains the adjusted estimates. So these are not perfect.

    However, working backwards.

    58.5% of Men are too heavy (overweight or obese by BMI), 77.7% of men are miscategorized across that boundary. So 45.5% of all men were too heavy and miscategorized. However, in aggregate the authors claim that only 37.4% of men were miscategorized. So there's some issue with either rounding or confidence intervals that I can't work back from in the data. Either way, that reasonably confirms that all, or very very close to all, of the people miscategorized were at the overweight/obese boundary and not the ideal/overweight boundary.

    For women it's closer. 58.5% of women are too heavy. 62.8% of those are miscategorized. So 21.7% of women are both too heavy and miscategorized. But the authors say 26.1% of all women are miscategorized. Again, I suspect there are errors because of background weighting. But it clearly shows that women miscategorized among the too heavy greatly outnumber those miscategorized at the ideal/overweight boundary. By an order of magnitude (10:1) most likely.

    Again, this is all very rough, because I don't have the raw data, I can only work backwards from the final calculations, which are weighted to account for difference in the number of participants in different demographics, normal.

    If I had more time I could maybe work backwards further using their confidence intervals and other statistical measures presented, but I wanted to pull this together in less than an hour.

    Anybody is welcome to work their own numbers if they like.
  • Azdak
    Azdak Posts: 8,281 Member
    SezxyStef wrote: »
    Azdak wrote: »
    JerSchmare wrote: »
    I hate these threads. Generally, BMI is a good indicator, but not always. There are other factors. However, most overweight people think they’re an outlier, but they’re not, they’re just simply overweight.

    As someone who works with hundreds of overweight people per year, I have found that almost no one actually thinks this way. They all know they are overweight.

    do you really think that those who think they are outliers are seeking help? no they are not...they think they are fine the way they are (as far as weight goes) so why would they seek out you???? and ergo how could you have conversations with them....

    I didn’t say they were “seeking help”. They are coming in for fitness assessments. I’ve done lots of them-as well as numerous screenings—on people of all shapes, sizes, and motivations. I’ve likely done more body composition assessments than anyone on these forums-maybe even more than everyone combined.

    This stereotypical fat person who denies their obesity and claims to have “big bones” doesn’t exist in any significant number.

    They are far, far, far, far outnumbered by those who-on both the low end and the high end—are confused because they know their bodies are different, and are constantly being judged by people —but don’t understand exactly why or how their bodies fit in the continuum of body types.






  • Azdak
    Azdak Posts: 8,281 Member
    jdlobb wrote: »
    Azdak wrote: »
    SezxyStef wrote: »
    SezxyStef wrote: »
    Azdak wrote: »
    SezxyStef wrote: »
    tomteboda wrote: »
    SezxyStef wrote: »
    1st one is an abstract and is from 2002...almost 20 years old????

    I'm sure you are capable of finding the full article and reading it. I know I managed to do it. And I'm not sure why you have an issue with an article published 15 years ago. Unless time itself invalidates science.
    SezxyStef wrote: »
    and it doesn't address your assertion that bone size difference can account for 8+lbs in body weight variance of two people who are same gender, height and race.
    Except the first study does. And I didn't make any assertion in particular giving a number, you must be confusing me with another poster. HOWEVER...
    SezxyStef wrote: »
    and the 2nd one doesn't prove anything about your original assertion either...we know that Asians have a different BMI scale than we do and has nothing to do with your original argument or the original post...
    How is it that you can recognize interracial genetic frame differences that result in real health outcome differences related to BMI, but cannot accept that individual variation within populations is also real and significant?
    SezxyStef wrote: »
    My original assertion..BMI is a good measure for the average population and that there are few outliers in that population...and that it is not "bone size" that will account for people being categorized as overweight or obese it's fat.
    I don't argue that for an "average human being", whatever that is, BMI is a rough indicator of body fat. I do argue:
    1. that the cutoff of 25 is arbitrary and not supported by morbidity and morality data for all populations. The existence of separate recommendations for Asians is evidence.
    2. The BMI scale itself is flawed because it assumes a relationship of height to volume (mass) of h*h while volume is a cubic relationship. Being stochastically fitted for a height of 5' even, the error is linearly increasing with deviation from that height. This is not particularly controversial from a mathematics standing.
    3. As a matter of mathematical interest, if my bones alone, never mind the volume of everything else in me, account for 15% of my mass, and my friend's bones are 12% of hers, then exactly 7.6 lbs of our weight difference is just bones. Now, personally, I find it really stupid that if I gain 10 lbs I'm classified as "overweight" but she has to gain 35 lbs to be "overweight". Because my body is clearly larger in frame and muscle. That is a pretty good illustration of the arbitrary nature of BMI when applied to individuals not populations.
    4. Also on that matter, the fit of BMI to body fat is considered generally good... To one standard deviation. That's 68%. OK, great. That means if the population is normally distributed 32% are outliers.

    If you found the article why link in the abstract????

    2nd point you responded to me saying 8lbs of bone was a bit much imo with a negative assertion that it was possible based on you and your friend and there are 2 links...1 is an abstract that doesn't prove it and neither does the 2nd.

    No where did I say frame size of people was all the same...I said 8lbs of it was a bit much imo and that for those people claiming frame size keeps them in the overweight of bmi they were in denial...perhaps you have me confused with another poster.

    Now onto the meat of it.

    comparing 12% for your friend and 15% is flawed...apples to apples.

    and perhaps you are one of those individuals who is in denial because you are almost in the overweight category????and that is causing a bias in your argument...been there done that until I wasn't in the overweight category and still wearing a size 8 shoe...and still "big boned" but a hella lot less fat.

    I think accusing someone of being “in denial” about their body because you disagree with them on a point of them on a point of science is out of line and deserves an apology.

    I am not disagreeing on a point of science. She disagreed and argued that she is "bigger" because of bone size...I say no way...people who think that are in denial and are more fat than they want to admit.

    Point of science is this.

    BMI is a good measure for the average person (at least it is currently)
    12-15% of the body weight of a person is from bone no more no less.
    if you are in the overweight category for BMI it's not from bones...chances are you are overfat (unless an outlier who has exceptional muscle mass) and yes I will say that there are those who are outlier.

    This poster is not.

    ETA: so no apology will be forthcoming from me.

    That poster isn't overweight. She's within healthy range for BMI. You just moved the goalposts. She's near the top range for her BMI because she has a large frame.

    She's not in denial and yes, you do owe her an apology.

    1. I never said she didn't have a large frame.
    2. She contended bmi is not valid due to bone size which is invalid.
    3. I never said she was over weight I said she might be on the top end because she had more weight than she wants to admit aka denial.

    And I will not apologize for that.

    I will stand by my original statement that those who say bmi doesn't apply to them are most likely in denial as the outliers are not that common.

    People who are not educated in exercise science often use “bone size” as a substitute for “higher LBM”, since they are not familiar with other terminology. Fixating on their use of “bone size” because it is not precisely accurate confuses the issue

    I can say with 100% certainty that the number of “outliers” from the BMI ranges is at least 20%. I can also say with 100% certainty that the actual number of people “in denial” about their weight is less than 10%.

    Most of the people who have unrealistic expectations about their weight are those with “large frames” who think they can/should be able to reach the lower end of the BMI range for their height.

    nope and nope.

    First, you absolutely can't say that with any certainty. You say that from your gut, because it SEEMS that way to you. But I challenge you to find a study that supports either of those suppositions.

    You can "believe" them if you chose to. But there is a high probability that you are wrong on both counts.

    On this particular subject, I have enough data points that I can speak with a reasonable level of expertise. I don’t make statements like that casually.


  • Packerjohn
    Packerjohn Posts: 4,855 Member
    Just go to any public beach. You'll get visual verification (sometimes might make your eyes burn) that 70% of the population is overweight/obese and as many or more are overfat (even at a "normal' bmi).
  • tomteboda
    tomteboda Posts: 2,171 Member
    Azdak wrote: »
    SezxyStef wrote: »

    1. I never said she didn't have a large frame.
    2. She contended bmi is not valid due to bone size which is invalid.
    3. I never said she was over weight I said she might be on the top end because she had more weight than she wants to admit aka denial.

    And I will not apologize for that.

    I will stand by my original statement that those who say bmi doesn't apply to them are most likely in denial as the outliers are not that common.

    People who are not educated in exercise science often use “bone size” as a substitute for “higher LBM”, since they are not familiar with other terminology. Fixating on their use of “bone size” because it is not precisely accurate confuses the issue

    I can say with 100% certainty that the number of “outliers” from the BMI ranges is at least 20%. I can also say with 100% certainty that the actual number of people “in denial” about their weight is less than 10%.

    Most of the people who have unrealistic expectations about their weight are those with “large frames” who think they can/should be able to reach the lower end of the BMI range for their height.

    I feel I have a couple of points to clarify.

    Sezxy: I did not say BMI is "not valid" (in total). I said it has QUALIFIED use. Which is to say it's not (as Aaron pointed out above) a tool that was designed or meant to be applied to judge any individual's health, but rather a good judge of populations, and a rough estimate for people who fall within a standard deviation of the mean for all body aspects (hip width, bone density, musculature, etc).

    A detailed defense of my not being in denial is following in the spoiler.
    I hate to take this detour. I felt the point that I was not in denial was well-defended by others, I really don't understand why you had to throw it in. But since it's now been hammered on (though it isn't salient) let me put this here:
    • current height 5'8.25" - weight 155 lbs . BMI = 23.4
    • tallest height 5'11" BMI = 21.6
    • doctor-estimated real height 6'1" BMI = 20.4
    My weight is not "at the top" even at my current height, much less at my tallest height or doctor-estimated real height. My friend has a BMI of 18.8 - she is very, very lean, but she also has narrow hips and shoulders, and little to no noticeable musculature. I, on the other hand, have extremely noticeable muscles. It would make a good deal of sense to estimate that she has light bones on top of a small frame because osteoporosis runs in her family; on the other hand, it's nearly unheard of in mine.

    Between the two of us, if our bone density falls at opposite ends of the normal range of most people, which seems likely, that difference alone accounted for nearly 8 lbs, your arbitrary "impossible" number. I imagine the rest of it is mostly lean body mass difference, though not all.. I do have a rather generous bosom even now, after all (34 DD to her 32 A). However, I am quite lean at this point. You can see shadows from my ribs front, back and side. I've got that hip bone ridge thing going on (wow does that hurt if I bump into something!), a flat stomach, and am starting to show muscle definition in my arms, calves, thighs, and abs. As a large-framed individual (by both current wrist and ankle measurements) that shouldn't be overly surprising.

    It remains a valid observation that for an arbitrary weight cutoff uniform to all people of a given height that I will be far leaner than she would be at that given weight; and that means that health effects due to having too much adiposity would kick in for her at a much lower absolute weight than I. You can argue about the need to label her "overweight" at a lower weight, which may be and was the impetus for WHO recommendations to lower SOME Asian regions' cutoffs (interestingly they actually raised the cutoff for others!)

    WHO, E. C. (2004). Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet (London, England), 363(9403), 157.

    The WHO has made available a PDF of the above citation for personal use only.

    Now, if the WHO has taken the position that, for example, it is appropriate to label rural Thailanders "overweight" only above a BMI of 27, why is it such a contentious idea that there are other populations that demonstrate similarly higher risk-weight profiles?


    Adzak, "bone size" is a real thing. People's bones vary in density. Weight is not the only thing that will create denser bones, any repeated, load-bearing stress (such as heavy work or weight lifting) will do the same thing. It doesn't generally account for everything, but I demonstrated that frame size (which refers to the overall breadth of skeletal structure) can account for considerable weight differences (just under 8 lbs) at the far ends of people considered to be within normal frame distribution. I specifically did not calculate the differences in other lean body mass aspects, such as organs or muscles, because the calculations would've required even more research, and because 8 lbs was the arbitrary weight differential that I was replying to.

    p.s.
    Holy Mother of Nested Quotes, Batman! I think I cut 8 or 9 layers out there to make this reply legible
  • rheddmobile
    rheddmobile Posts: 6,841 Member
    edited November 2017
    Ok maybe BMI wasn’t the best way to frame it. What I’m hearing though is that y’all generally believe there is an ideal body weight / body size / body fat percentage range that people should be in? And that being outside that range indicates less-than-optimal health? And that people should strive to be close to or within this range?

    There is definitely such a thing as being at a healthy weight and being at an unhealthy weight. What that is looks different on different people. Many models, including so called fitness models, are unhealthy because they are underweight - however, since this lacks the same stigma in society, you don't see them trying to fatten up, even though they may have lost their periods and have osteoporosis. I had problems with fainting, anemia, and reactive hypoglycemia when I was underweight as a teen model.

    And then there's obesity. Recent research indicates that even apparently healthy obese people are at heightened risk for several health conditions.

    I can say, speaking for myself, that not only am I healthier at "normal" BMI, but that I feel a distinct change in my ability to perform as an athlete at almost exactly the dividing lines of the BMI chart. When I was morbidly obese I could barely function. When I was obese, I could walk but not run easily or jump or touch my toes. When I hit overweight, I could do those things but I could also tell I wasn't doing them as well as I potentially could. I recently hit the top end of normal BMI and can do things like bend over and touch my forehead to my knees, without my gut being in the way. Running is much easier.

    However, it's pretty much coincidence that my body type coincides closely with the BMI chart, and it doesn't work so well for everyone.

  • bmeadows380
    bmeadows380 Posts: 2,983 Member
    Aaron_K123 wrote: »
    There is nothing wrong with BMI as a measure, it is what it claims to be....a statistical distribution. People just don't know how to interpret statistical distributions......All BMI is is a quick way to estimate things like obesity within populations based off of statistical distributions. It is a way of converting a large dataset of collected height/weight info (which is commonly available) and converting it into a measure of percent obesity within a population (which is info not commonly available). If you use it for that purpose then it is quite accurate. If you use it as your own personal target for weight gain/loss regardless of your body composition then that is you misunderstanding what BMI is for, not BMI being "wrong".

    People misusing a tool does not somehow invalidate it as a useful tool.

    To answer the title of the thread, no...not everyone is intended to be in the "healthy" BMI range, that isn't what BMI is for. Its a tool for making inferences based on large datasets based on statistical population distributions...it is not a tool to set a goal for yourself.

    The sad part about this is that many in the health field don't seem to get this. For instance, my company has a healthy living program going on to try to encourage folks to be healthier (less cost to the company that way, of course). The company running the program, called Provant, sets markers for what they consider to be healthy. One of their die-hard, set in stone markers is BMI. They've only recently added waist circumference as a second measure, but if you want the credit, you still have to be within the BMI number, with no modifiers available whatsoever.

    Another frustrating thing to me about Provant is that their ideal healthy range in other areas don't match up. For instance: they will not credit you for having good HDL unless its above 60, though the American Heart Association says that while above 60 is ideal, anything above 40 is normal.

    Their dietary advance is pretty much the food pyramid as well. *sigh* but if I want cheaper health insurance, I have to jump through as many hoops as I can with this outfit.