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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

  • Packerjohn
    Packerjohn Posts: 4,855 Member
    edited October 2017
    Azdak wrote: »
    Packerjohn wrote: »
    Certainly not, I'm personally around 10% bodyfat but have a high BMI.
    I would be discouraged if my BMI fell into the healthy range because that would ultimately mean a reduction in muscle mass (given that my bodyfat is already low, it would be the only way for it to do so).

    BMI is a very flawed calculation, I have friends who are doctors, nurses and I'm personally a qualified fitness professional and I would struggle to find anybody with anything good to say about BMI as a measurement of health.

    As a fitness professional would you agree that few people are active, and do enough resistance work to have a lower BF at a higher BMI? Since in the US only around 20% of the adult population strength trains 2 or more times a week ( and God only knows the level of intensity), and there are minimal manual labor job it would be a stretch to thing much more than 10% of the people with a higher than normal BMI are really muscular.

    Bringing us back to the idea that BMI is a decent indicator for 80-90% or so of the population.

    Maybe it is, but I find it useless when counseling clients. The only time I ever mention it is if someone is an “outlier”— I explain to them why it doesn’t apply to them and to ignore any recommendations they receive based on BMI.

    I have always used the “outlier” argument as a criticism against BMI, but I think cwolfman13’s earlier observation might be even more significant.

    Since the “healthy” range of BMI does not take account the range of LBM and frame sizes in the population, it provides a poor reference point, even for those 80-90%. Someone who naturally lands in the upper end of their BMI range might incorrectly assume that anyone can reach the bottom end of the range.

    The conundrum is that those professionals who fully understand BMI and who are most qualified to explain it, are probably the least likely to use it as a reference tool. And those who rely on it the most are the least qualified to explain it and put it in proper context.

    But for a regular Joe/Jane, trying to decide if they are an appropriate weight isn't it a pretty good reference for most people? As mentioned above, there is typically a 30-40 pound range of "normal" weight for any given height. I would not expect a fitness/medical professional to use BMI as an all encompassing diagnostic tool (if they did I would run the other way). Being at an overweight/obese/underweight BMI should be a sign to discuss one's weight with a medical professional. NOTE, I'm not saying run to the doctor if the scale shows someone is .1 point into overweight, just a conversation to have at your next doctor appointment.
  • Azdak
    Azdak Posts: 8,281 Member
    Packerjohn wrote: »
    Azdak wrote: »
    Packerjohn wrote: »
    Certainly not, I'm personally around 10% bodyfat but have a high BMI.
    I would be discouraged if my BMI fell into the healthy range because that would ultimately mean a reduction in muscle mass (given that my bodyfat is already low, it would be the only way for it to do so).

    BMI is a very flawed calculation, I have friends who are doctors, nurses and I'm personally a qualified fitness professional and I would struggle to find anybody with anything good to say about BMI as a measurement of health.

    As a fitness professional would you agree that few people are active, and do enough resistance work to have a lower BF at a higher BMI? Since in the US only around 20% of the adult population strength trains 2 or more times a week ( and God only knows the level of intensity), and there are minimal manual labor job it would be a stretch to thing much more than 10% of the people with a higher than normal BMI are really muscular.

    Bringing us back to the idea that BMI is a decent indicator for 80-90% or so of the population.

    Maybe it is, but I find it useless when counseling clients. The only time I ever mention it is if someone is an “outlier”— I explain to them why it doesn’t apply to them and to ignore any recommendations they receive based on BMI.

    I have always used the “outlier” argument as a criticism against BMI, but I think cwolfman13’s earlier observation might be even more significant.

    Since the “healthy” range of BMI does not take account the range of LBM and frame sizes in the population, it provides a poor reference point, even for those 80-90%. Someone who naturally lands in the upper end of their BMI range might incorrectly assume that anyone can reach the bottom end of the range.

    The conundrum is that those professionals who fully understand BMI and who are most qualified to explain it, are probably the least likely to use it as a reference tool. And those who rely on it the most are the least qualified to explain it and put it in proper context.

    But for a regular Joe/Jane, trying to decide if they are an appropriate weight isn't it a pretty good reference for most people? As mentioned above, there is typically a 30-40 pound range of "normal" weight for any given height. I would not expect a fitness/medical professional to use BMI as an all encompassing diagnostic tool (if they did I would run the other way). Being at an overweight/obese/underweight BMI should be a sign to discuss one's weight with a medical professional. NOTE, I'm not saying run to the doctor if the scale shows someone is .1 point into overweight, just a conversation to have at your next doctor appointment.


    Your original statement was what started my thinking. And I fully admit I may be way too “inside” to fully grasp the lay persons POV. I was just thinking about all the people I assess and counsel and I can’t think of one instance in which BMI was a useful addition to the conversation. I can think of dozens and dozens of times when I had to caution people against relying on it, because the numbers were so skewed.

    Not the most scientific analysis, I know.

  • cwolfman13
    cwolfman13 Posts: 41,879 Member
    yskaldir wrote: »
    Certainly not, I'm personally around 10% bodyfat but have a high BMI.
    I would be discouraged if my BMI fell into the healthy range because that would ultimately mean a reduction in muscle mass (given that my bodyfat is already low, it would be the only way for it to do so).

    BMI is a very flawed calculation, I have friends who are doctors, nurses and I'm personally a qualified fitness professional and I would struggle to find anybody with anything good to say about BMI as a measurement of health.

    Just out of curiosity I looked at your pictures and you look higher than 10%. I suspect a lot of the "outliers" are simply under estimating their body fat.

    Even if he was underestimating, from a health standpoint, up to 20% BF is deemed "acceptable"...he certainly isn't anywhere near 20% BF...so regardless of whether he's 10% or 12% or whatever, he's overweight per BMI, but at a perfectly healthy BF%.

    I don't find it atypical for active males to be slightly overweight per BMI...especially if they're like me and aren't super lean, but still at a healthy BF%.
  • amusedmonkey
    amusedmonkey Posts: 10,330 Member
    Intended, no. Can, probably yes. Want? That's up to the person and their own risk assessment.
  • jgnatca
    jgnatca Posts: 14,464 Member
    It’s a bell curve.

    https://m.imgur.com/gallery/JVTBW
  • jgnatca
    jgnatca Posts: 14,464 Member
    You look far finer than the absurd illustration.
  • HealthyBodySickMind
    HealthyBodySickMind Posts: 1,207 Member
    jdlobb wrote: »
    This is kind of a silly question.

    Nearly everyone in the world, say 95%+ of the population, CAN be in the healthy BMI range.

    Building enough muscle to push you into being overweight despite low BF% take additional effort beyond what would be considered "normal" exercise. It doesn't happen by accident.

    I don't believe for even one second that "bone density" or "frame" can, on their own, force a person to be outside the healthy BMI range.

    I'll actually argue that point, but from the other end of the curve. Healthy BMI is 18.5-24.9. Before I started weightlifting, my small frame put me at about an 18 BMI, but I don't think anyone (certainly not my doctor) would have considered me unhealthy. My cholesterol numbers were normal, my cycles were normal, and I ate an appropriate amount of food for my size and activity level. Weightlifting brought my bmi up to the 18.5 to 19 range, but even pregnancy didn't push it to 25.
  • NorthCascades
    NorthCascades Posts: 10,970 Member
    jdlobb wrote: »
    jgnatca wrote: »

    can we address the absurd image they use to illustrate muscle vs fat?

    svR8cia.gif


    I'm 6 feet tall, and weighed 250 pounds just a few week ago. That person on the right is an incredibly poor representation of a 250 pound, 6 foot tall person. A person with those body dimensions would weigh closer to 350-400 pounds.

    You're right, but it's just to demonstrate a point.
  • cwolfman13
    cwolfman13 Posts: 41,879 Member
    jdlobb wrote: »
    jgnatca wrote: »

    can we address the absurd image they use to illustrate muscle vs fat?

    svR8cia.gif


    I'm 6 feet tall, and weighed 250 pounds just a few week ago. That person on the right is an incredibly poor representation of a 250 pound, 6 foot tall person. A person with those body dimensions would weigh closer to 350-400 pounds.

    But this is the illustration they always use.

    Here is a picture of me, 6 feet tall, at exactly 250 pounds.

    1htHFbJl.jpg

    I have LBM of 153 pounds, the upper end of my healthy BMI is 180 pounds. At 180 pounds I would be right at 15% BF.

    I bet if you get down to 180 Lbs you will be leaner than you think, particularly as you're lifting.
  • jdlobb
    jdlobb Posts: 1,232 Member
    cwolfman13 wrote: »
    jdlobb wrote: »
    jgnatca wrote: »

    can we address the absurd image they use to illustrate muscle vs fat?

    svR8cia.gif


    I'm 6 feet tall, and weighed 250 pounds just a few week ago. That person on the right is an incredibly poor representation of a 250 pound, 6 foot tall person. A person with those body dimensions would weigh closer to 350-400 pounds.

    But this is the illustration they always use.

    Here is a picture of me, 6 feet tall, at exactly 250 pounds.

    1htHFbJl.jpg

    I have LBM of 153 pounds, the upper end of my healthy BMI is 180 pounds. At 180 pounds I would be right at 15% BF.

    I bet if you get down to 180 Lbs you will be leaner than you think, particularly as you're lifting.

    eating a large calorie deficit it's nearly impossible that I will add any lean mass between now and then, it's far more likely that by the time I get to 180 I will be down to a LBM of 150 or less, even with lifting. So I'll be around 15% - 18% BF at that time. I know what that looks like, and it's hardly "lean." I'd say it's firmly "average."
  • brendanwhite84
    brendanwhite84 Posts: 220 Member
    SezxyStef wrote: »
    I always find those that dismiss BMI as a decent measure for the average person usually don't fall in the healthy range and either believe it's due to "bone" size etc or are in denial about their weight.

    There are outliers in the world and they will fall outside the "health range" but not often and not for their entire life.

    I used to think I would never fit in the healthy range due to "bone size'...psh...I was so in denial about being overweight/fat.

    I seem to recall reading somewhere (if someone can find something like this, please post it) that two people of the same gender and height can have their skeletal mass differ by roughly 8 lbs.

    Anecdotally, in my experience "big bones" mostly come up from people who've never had a DEXA scan or other reliable body composition testing done. :neutral: