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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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  • jseams1234
    jseams1234 Posts: 1,217 Member
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    lemurcat12 wrote: »
    jdlobb wrote: »
    Which is literally the exact opposite of why most people in this thread hate BMI.

    I seriously doubt that "most people" in this thread "hate BMI."

    Maybe one or two drop ins, probably no regular posters, but I suppose I could be wrong. Maybe those who "hate BMI" could identify themselves.

    Don't hate it at all and I have a BMI of 31. Technically, I'm "obese". It doesn't bother me. Had a physical yesterday. Nurse who took my vitals noted BMI but my Doctor, after the physical just noted "well developed mm". He was more curious about a series of lifting injuries I've had and never mentioned my weight.

    My wife thinks I'm too big, but she's a shorty and I was pretty skinny when we met. ;)
  • mitch16
    mitch16 Posts: 2,113 Member
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    lemurcat12 wrote: »
    jdlobb wrote: »
    Which is literally the exact opposite of why most people in this thread hate BMI.

    I seriously doubt that "most people" in this thread "hate BMI."

    Maybe one or two drop ins, probably no regular posters, but I suppose I could be wrong. Maybe those who "hate BMI" could identify themselves.

    I don't hate BMI.

    When mine was above 26 I was, truly, obese. I am smack in the middle of the normal range right now and I'm still fatter than I want to be.
  • lemurcat12
    lemurcat12 Posts: 30,886 Member
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    WinoGelato wrote: »
    lemurcat12 wrote: »
    jdlobb wrote: »
    Which is literally the exact opposite of why most people in this thread hate BMI.

    I seriously doubt that "most people" in this thread "hate BMI."

    Maybe one or two drop ins, probably no regular posters, but I suppose I could be wrong. Maybe those who "hate BMI" could identify themselves.

    I was rather ambivalent toward BMI prior to this thread, but the longer it goes on, the more negative I am becoming. Oh wait, it's just the thread about BMI that I hate, not the measurement itself...

    Heh, I'm with you there!
  • jdlobb
    jdlobb Posts: 1,232 Member
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    tomteboda wrote: »
    Ok maybe this chart will help a bit because my argument is NOT ABOUT ME. No matter how many times certain people try to make it about me. I shouldn't have used myself as an example. So this is the actual math.

    the "healthy" range for most height is 35 pounds. way more than enough to cover the disparity due to bone size.



  • tomteboda
    tomteboda Posts: 2,171 Member
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    For individuals of high lean body mass (large frame and musculature) who are perfectly within normal variation, the bmi cutoffs to define "healthy" represent a much tighter limit on body fat than for those with low lean body mass.

    From a health standpoint it is nonsensical as adipose tissue is the greatest contributors to morbidity and mortality, and gross weight is a crude stand-in with significant failures in over - estimating body fat for some groups while under - estimating in others. In practice it means that a small - framed individual has a wide healthy range possible while a large - framed one will only have a small range because their mass art any body fat percentage will be higher.
  • tomteboda
    tomteboda Posts: 2,171 Member
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    Again, I'm not arguing that bmi is useless. I'm arguing that it is not a good universal metric to determine the health of individuals. This is the same thing Quilette himself said when he developed the index. It's also why it's wrong to say "you are unhealthy if you have a bmi of over 25". That argument, while epistological, is not scientific.
  • SezxyStef
    SezxyStef Posts: 15,268 Member
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    tomteboda wrote: »
    The point. Someone ages ago said it was impossible that bones had different weights, much less 8 lbs( their arbitrary number). I am demonstrating that this is just not true, that skeletal differences are real and significant.

    People keep trying to draw extra conclusions from this that I am not making. This is irritating me to no small extent.

    Where was it said it was impossible that bones didn't have different weights.

    Where was it said that the bones didn't account for some difference in bmi.

    And the 8lbs came from a post where the individual said they couldn't find the study.
  • tomteboda
    tomteboda Posts: 2,171 Member
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    And finally, why this dry mathematical argument matters : there are real financial consequences if you are labled "overweight" for many individuals, either through premium penalties or loss of incentives. In the UK there may be health care consequences, as denying care to the overweight and obese is being used as a way to save money. So getting the metric that predicts health vs disease right is important.
  • stanmann571
    stanmann571 Posts: 5,728 Member
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    Orphia wrote: »
    jdlobb wrote: »

    So they found that 17.3% of women and 31.6% of men identified as obese by BMI were overweight based on BF%, and that 19.9% of women and 41.6% of men identified as overweight by BMI were obese by BF%

    Net/Net, this still means that BMI is too forgiving, and that it actually gives weight targets that are TOO HIGH for most people. WHICH I'M PRETTY SURE A LOT OF PEOPLE HERE WOULD HAVE A PROBLEM WITH.



    So it's NOT as you asserted a tool that makes a meaningful assertion for 95% of the population.

    Ultimately, that's what it boils down to and all I was asserting

    For 20% of women and 35% of men it gets it wrong

    Half of those women and men are given false comfort and half false concern, but regardless, they're getting the wrong message.

    Which is notwithstanding the part that Overweight BMI is misleadingly labeled.

    Maths correction:

    Not 20/35% of all participants. Only 20/35% of a percentage of the participants.

    It gets it wrong for 20% (17.3% actually) of the women identified as obese by BMI, which was 20% (I'll be generous) of 301/1045 women which is 5.7% of all women in the study.

    It gets it wrong for 35% of men identified as obese by BMI, which was 35% of 294/1446 men which is 7.1% of all men.

    The actual figure for people identified as overweight by BMI is 20% of 326/1045 for women which is 6.2%, and for men 41.6% of 682/1446 which is 19.6% who men were actually obese by BF%.

    Can you see where you made the error?

    You're right,

    I should have just quoted the study
    There was exact agreement using sex-and-age-specific %BF and BMI criteria for categorising underweight, ideal weight, overweight and obese groups for 62.6% men (κ = 0.4) and 73.9% women (κ = 0.6)

    37.4% of men were mischaracterized across categories and 26.1% of women.

    Can you see where you made the error?
  • Orphia
    Orphia Posts: 7,097 Member
    edited November 2017
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    Hmm, cross purposes. My figures are correct, as are the ones you quoted.

    37.4% of men were mischaracterized across categories and 26.1% of women.

    It looked like you were talking about just obese and overweight BMI because you bolded the first quote I quoted.

    No hard feelings.


    Not directed at you:

    So, to sum up the study, surprise, surprise, some people were above average, some people were below average, and one method of estimating is a bit different to another method of estimating. Who'd have thought? :smile:
  • stevencloser
    stevencloser Posts: 8,911 Member
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    This is me at 6lbs OVER the very tip top of my "healthy" BMI range:
    s2a2necpiexc.jpg

    Being overly muscular is not a prerequisite for there being variations in the applicability of BMI. At the outer edges of height distribution, there are similar, documented issues to those that are constantly pointed out for athletes and bodybuilders.

    You are by no means fat, but there's still weight you could safely lose if you wished so, putting you back into the healthy BMI range.
    Besides, at a measly 6 pounds over it I wouldn't sweat it to begin with.
  • accidentalpancake
    accidentalpancake Posts: 484 Member
    edited November 2017
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    This is me at 6lbs OVER the very tip top of my "healthy" BMI range:
    s2a2necpiexc.jpg

    Being overly muscular is not a prerequisite for there being variations in the applicability of BMI. At the outer edges of height distribution, there are similar, documented issues to those that are constantly pointed out for athletes and bodybuilders.

    You are by no means fat, but there's still weight you could safely lose if you wished so, putting you back into the healthy BMI range.
    Besides, at a measly 6 pounds over it I wouldn't sweat it to begin with.

    I completely agree, but the point is that the ranges are inadequate the further away from "average" height you get. While I could lose a couple of pounds and still be fine, the fact is that being categorized as "overweight" at 6'3" and 205lbs with a healthy BF% is laughable.

    I don't sweat it at all. BMI is a relic that needs to be retired. The issue is that it has real consequences for people via health insurance premiums. If my provider bought into the nonsense, I'd either be charged more, or fail to receive a "discount" due to being overweight, which I clearly am not by any reasonable standard.
  • lemurcat12
    lemurcat12 Posts: 30,886 Member
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    This is me at 6lbs OVER the very tip top of my "healthy" BMI range:
    s2a2necpiexc.jpg

    Being overly muscular is not a prerequisite for there being variations in the applicability of BMI. At the outer edges of height distribution, there are similar, documented issues to those that are constantly pointed out for athletes and bodybuilders.

    You are by no means fat, but there's still weight you could safely lose if you wished so, putting you back into the healthy BMI range.
    Besides, at a measly 6 pounds over it I wouldn't sweat it to begin with.

    I completely agree, but the point is that the ranges are inadequate the further away from "average" height you get. While I could lose a couple of pounds and still be fine, the fact is that being categorized as "overweight" at 6'3" and 205lbs with a healthy BF% is laughable.

    I don't sweat it at all. BMI is a relic that needs to be retired. The issue is that it has real consequences for people via health insurance premiums. If my provider bought into the nonsense, I'd either be charged more, or fail to receive a "discount" due to being overweight, which I clearly am not by any reasonable standard.

    It's absolutely correct that it's more inaccurate at taller and shorter heights (in different directions), as well as for non-whites (in different directions), so on. I don't think that means it is "a relic that needs to be retired." I think it means that someone insisting that BMI is the be-all, end-all of what's a proper weight is being ignorant, that people should realize these are ranges and there's not like there's some bright line between being 24.5 BMI (great!) and 25.5 BMI (fat, terrible!). I also think acknowledging that for the most part BMI is an easy proxy for what we can better determine from an accurate BF% and the latter is more significant also is important.

    I think in many ways this thread is an example of miscommunication, as I am reading (perhaps wrongly) a few participants to be insisting that one should ALWAYS strive to be below 25 BMI and not being so is inherently bad, no matter what, and I think those people are (IMO wrongly) reading everyone saying it's more nuanced to be making excuses for their own weights. Most people seem to fall more in the middle anyway.

    I agree that to the extent someone gets charged more for insurance solely for being a 25 or over BMI, even without being overfat by BF%, that's wrong. I do wonder (don't know) how common that is. As I keep saying, my own insurance has never included differential pricing, but it's method promoted for determining if you are a healthy weight includes BMI + waist measure, and if the waist measure is fine the overweight BMI is not considered a problem. Most wellness programs I've heard about allow reduced pricing based on a number of different measures, not merely BMI. But I've never seen stats and agree that anything based solely on BMI should not be (unless it kicked in at 30 and allowed you to show a BF measure to challenge it through some system).