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BMI calculations...

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Replies

  • Hornsby
    Hornsby Posts: 10,322 Member
    For my 7 year old it is completely pointless. She is a gymnast and trains 8 hours a week, full on training. She has a lot of muscle, she has no fat on her at all, a six pack yet her BMI is close to being overweight?

    But she is in the normal range? Not the overweight category, no? So the range works... Being close to the overweight category matters none. The range is there for a reason. Higher in the range isn't "worse" than being dead center of the normal range.
  • Wheelhouse15
    Wheelhouse15 Posts: 5,575 Member
    For my 7 year old it is completely pointless. She is a gymnast and trains 8 hours a week, full on training. She has a lot of muscle, she has no fat on her at all, a six pack yet her BMI is close to being overweight?

    BMI isn't used for children, they go by a percentile chart but even then doctors will look at all aspects since children aren't miniature adults.
  • Wheelhouse15
    Wheelhouse15 Posts: 5,575 Member
    AnvilHead wrote: »
    I think BF% is a better metric than BMI. I'd say it's more common to find overfat people at "healthy" BMIs than it is to find people with high BMI and low BF%. With that said, while BMI was originally intended to be a statistic used to study populations, not individuals, it's at least a valid ballpark figure for the vast majority of people.

    Some people seem to like to throw groups such as pro football players out there as examples of why BMI isn't valid. There are a couple factors complicating that argument: 1) Many pro football players are using PEDs, which will make them outliers in terms of muscle mass. 2) If you look at linemen (who are the "behemoths" of the NFL), they're carrying quite a bit of bodyfat along with their muscle. It's rare to see an offensive lineman who isn't at least 30-35% BF. No denying they're strong as bears and in better physical shape than the general population, but that still doesn't change the fact that carrying all that extra fat has the potential to create health issues.

    Pro football players often lose a lot of weight very quickly after they end their career because they know it's not healthy to be over 300lbs no matter how you get there. The life expectancy of a player doesn't seem to be too promising for a lot of reason, of which I'm guessing being that heavy is one factor.
  • Chadxx
    Chadxx Posts: 1,199 Member
    Chadxx wrote: »
    Chadxx wrote: »
    Chadxx wrote: »
    BMI is all but worthless. It is supposed to be a reasonable estimate of a healthy level of body fat and in that regard it BS. There are lots of unhealthy people at a "healthy BMI" and you don't have to look anything like the Rock to be at an overweight or even obese BMI, particularly men. If you want to know if you are healthy, look in the mirror, actually check your body fat, check your blood pressure, check your cholesterol, etc.

    Yeah, it's so easy to be obese by BMI without being overfat, a 6 foot person would just have to be 220 pounds, putting them at least at 24 FFMI, and that's when you're at 20% bodyfat which is hardly the best bodyfat amount to have. That goes up to 26 if you go with an actually healthy bodyfat range. 25 FFMI is what's regarded barely still doable by people with great genetics. But yeah tell yourself so many people at healthy bodyfat amounts can be up to obese without that crazy amount of muscle.
    I swear, the skewed perception perpetuated thanks to pro bodybuilders is gonna be the death of my sanity.

    First of all, you skipped the overweight range entirely. Secondly, use whatever calculations you want but it really isn't that hard to exceed the normal or even overweight BMI ranges and be healthy. Last time I lost weight, I was still considered obese according to BMI charts but had abs showing and a 32" waist. That was after only 3 months back in the gym. A couple of guys I work with have 6 packs and are both overweight according to BMI and one of them can't even bench 300. I would hardly call that a bodybuilder.

    I have abs, a 30" and a BMI slightly in the overweight range and I bench 1.6x my bodyweight, but so what? What does that have to do with most people? Those of us who know the BMI doesn't work for us aren't that fussed about it in general because we know it's a population measure. For individuals it's just one of many tools and there are better ones for individuals, but a BMI measurement can still be a good check.

    Also, I seriously doubt you were in the obese range with a 10-15% BF unless you were running a decent stack. As Steve pointed out, you need to have a FFM that's extremely high and isn't something you get without drugs and years of serious training. Out of all of the bodybuilders, powerlifters, weight lifters (i.e. Olympic lifting) or wresters I've ever known (and I known tons), only a handful would ever have been BMI rated obese AND have an athletic BF% and they all had pro cards. I'm also not even going to touch the fact that these bodybuilders aren't really that healthy and their life expectancy is still reduced. It doesn't really matter how you get to obese BMI it doesn't seem to do much for longevity either way.

    The debate isn't whether BMI is a reasonable range for most people. The argument people are making is that it accurate for all but super rare cases. What I am saying is that there is a significant amount of people for whom BMI isn't accurate and I am also saying it tells very little of a person's overall health. As for me, I was benching 1.75 times my body weight and I really don't know what my body fat % was but I certainly wasn't "overfat". Also, I have never touched steroids of any kind, ever. BMI is nothing more than laziness. It exists only because it is easy. If you want to know if you are fat, check your bf% or look in the mirror. If you want to know if you are healthy, check your heart rate and blood pressure and have blood work done.

    The last part I agree with, even if you are in range you should have your blood screens and BP taken. Oh, and 1.75 is certainly within the range of naturals, my best when I was younger was 1.9xBW and that's not even in the elite range, what I was referring to was being obese BMI and having visible abs. You can be 25% and not overfat but obese BMI. BMI can be slightly off on the edges but those are always grey anyway. Of course, me defendig BMI is kinda odd lol, I don't really like it as an individual measure but rather a population metric.

    Now see, that last line is basically my point.

    I am 5'9". For me, overweight BMI starts at 170 pounds. I don't even have to lift to be over that while lean. Obese starts at 205 pounds. That is not very heavy for a guy with thick legs and broad shoulders. I was in really good shape then and did a lot of cardio. My stomach was really flat and my abs were showing but I never cut down to the point of really having 6 pack. That is one of many things I regret. This time, I am shooting for around 195 or so and a well defined 6 pack. At that point, I don't care what the scale says, just the mirror and camera. From there, I wouldn't mind bulking up some and getting my bench at least over 4 plates if my shoulder allows but I want to lean up first. Regardless, I will never see a normal BMI.
  • BinaryPulsar
    BinaryPulsar Posts: 8,927 Member
    It works for me. But, people can have different frame sizes and preferences. That's why there is a range. Some are healthy at the low end. Others are healthy at the high end.
  • Parkersspace
    Parkersspace Posts: 17 Member
    I'm 5'5", I am a professional ski instructor and I do ride a bike 2 hours plus a day on single track (mountain bike) when not skiing (along with a few other exercises tossed in to make it more well rounded. I have a BMI that ranges from 23.9 in the middle of ski season to 25.4 in off ski season. I have a waist measure that goes form 27 to 28 and hips that go 37 to 38. I am over weight but even following a 1200 calorie diet where i record every morsel, or going low carb will not pull my weight down in off ski season and it doesn't matter that I bike. During ski season I do lose a little and hit the so called healthy bmi, but after a month or so of carrying the lower weight I stop having my cycle and am starving all the time. So I don't know what's healthy and i have been this way all my life and I'm 51. The photo is current, a few weeks ago. Oh my triglycerides are 33 to 53, ldl 60 ish, HDL 80 ish, blood presure 115 over 60 ish when calm hehe, when nervous I've seen it as high as 122 over 60 but not usually. I say work with your doctor on what works for you, everyone is different and that is the only thing wrong with a bmi. it doesn't always predict health outcomes as weight should not be the only number a doctor looks at.
  • The_Original_Beauty
    The_Original_Beauty Posts: 162 Member
    For my 7 year old it is completely pointless. She is a gymnast and trains 8 hours a week, full on training. She has a lot of muscle, she has no fat on her at all, a six pack yet her BMI is close to being overweight?

    BMI isn't used for children, they go by a percentile chart but even then doctors will look at all aspects since children aren't miniature adults.

    This was using the children's percentile chart. Also when the doctor used a child's BMI chart
  • Wheelhouse15
    Wheelhouse15 Posts: 5,575 Member
    For my 7 year old it is completely pointless. She is a gymnast and trains 8 hours a week, full on training. She has a lot of muscle, she has no fat on her at all, a six pack yet her BMI is close to being overweight?

    BMI isn't used for children, they go by a percentile chart but even then doctors will look at all aspects since children aren't miniature adults.

    This was using the children's percentile chart. Also when the doctor used a child's BMI chart

    The doctor should also be considering their overall health and I'm not familiar with BMI charts for children but I'm not sure they should be used for clinical purposes.
  • Wheelhouse15
    Wheelhouse15 Posts: 5,575 Member
    Chadxx wrote: »
    Chadxx wrote: »
    Chadxx wrote: »
    Chadxx wrote: »
    BMI is all but worthless. It is supposed to be a reasonable estimate of a healthy level of body fat and in that regard it BS. There are lots of unhealthy people at a "healthy BMI" and you don't have to look anything like the Rock to be at an overweight or even obese BMI, particularly men. If you want to know if you are healthy, look in the mirror, actually check your body fat, check your blood pressure, check your cholesterol, etc.

    Yeah, it's so easy to be obese by BMI without being overfat, a 6 foot person would just have to be 220 pounds, putting them at least at 24 FFMI, and that's when you're at 20% bodyfat which is hardly the best bodyfat amount to have. That goes up to 26 if you go with an actually healthy bodyfat range. 25 FFMI is what's regarded barely still doable by people with great genetics. But yeah tell yourself so many people at healthy bodyfat amounts can be up to obese without that crazy amount of muscle.
    I swear, the skewed perception perpetuated thanks to pro bodybuilders is gonna be the death of my sanity.

    First of all, you skipped the overweight range entirely. Secondly, use whatever calculations you want but it really isn't that hard to exceed the normal or even overweight BMI ranges and be healthy. Last time I lost weight, I was still considered obese according to BMI charts but had abs showing and a 32" waist. That was after only 3 months back in the gym. A couple of guys I work with have 6 packs and are both overweight according to BMI and one of them can't even bench 300. I would hardly call that a bodybuilder.

    I have abs, a 30" and a BMI slightly in the overweight range and I bench 1.6x my bodyweight, but so what? What does that have to do with most people? Those of us who know the BMI doesn't work for us aren't that fussed about it in general because we know it's a population measure. For individuals it's just one of many tools and there are better ones for individuals, but a BMI measurement can still be a good check.

    Also, I seriously doubt you were in the obese range with a 10-15% BF unless you were running a decent stack. As Steve pointed out, you need to have a FFM that's extremely high and isn't something you get without drugs and years of serious training. Out of all of the bodybuilders, powerlifters, weight lifters (i.e. Olympic lifting) or wresters I've ever known (and I known tons), only a handful would ever have been BMI rated obese AND have an athletic BF% and they all had pro cards. I'm also not even going to touch the fact that these bodybuilders aren't really that healthy and their life expectancy is still reduced. It doesn't really matter how you get to obese BMI it doesn't seem to do much for longevity either way.

    The debate isn't whether BMI is a reasonable range for most people. The argument people are making is that it accurate for all but super rare cases. What I am saying is that there is a significant amount of people for whom BMI isn't accurate and I am also saying it tells very little of a person's overall health. As for me, I was benching 1.75 times my body weight and I really don't know what my body fat % was but I certainly wasn't "overfat". Also, I have never touched steroids of any kind, ever. BMI is nothing more than laziness. It exists only because it is easy. If you want to know if you are fat, check your bf% or look in the mirror. If you want to know if you are healthy, check your heart rate and blood pressure and have blood work done.

    The last part I agree with, even if you are in range you should have your blood screens and BP taken. Oh, and 1.75 is certainly within the range of naturals, my best when I was younger was 1.9xBW and that's not even in the elite range, what I was referring to was being obese BMI and having visible abs. You can be 25% and not overfat but obese BMI. BMI can be slightly off on the edges but those are always grey anyway. Of course, me defendig BMI is kinda odd lol, I don't really like it as an individual measure but rather a population metric.

    Now see, that last line is basically my point.

    I am 5'9". For me, overweight BMI starts at 170 pounds. I don't even have to lift to be over that while lean. Obese starts at 205 pounds. That is not very heavy for a guy with thick legs and broad shoulders. I was in really good shape then and did a lot of cardio. My stomach was really flat and my abs were showing but I never cut down to the point of really having 6 pack. That is one of many things I regret. This time, I am shooting for around 195 or so and a well defined 6 pack. At that point, I don't care what the scale says, just the mirror and camera. From there, I wouldn't mind bulking up some and getting my bench at least over 4 plates if my shoulder allows but I want to lean up first. Regardless, I will never see a normal BMI.

    I've been fighting a shoulder (rotatorcuff) injury for over a year they really suck! I wouldn't worry about the 6 pack, they are over-rated. I'd rather have bigger arms than a clear six pack.
  • Packerjohn
    Packerjohn Posts: 4,855 Member
    edited October 2016
    For my 7 year old it is completely pointless. She is a gymnast and trains 8 hours a week, full on training. She has a lot of muscle, she has no fat on her at all, a six pack yet her BMI is close to being overweight?

    Was the doctor, who I assume was personally examining her, concerned that she was close to overweight? If not, then like 10% of some of adults she is somewhat of an outlier i.e., people with significantly more muscle mass than normal and the charts aren't relevant for her.

  • curlsintherack
    curlsintherack Posts: 465 Member
    I used to think it was crap when I had 95 lbs to go. Now with only 37 more pounds to normal bmi I'm having my doubts. I'm not gonna beat myself up if I don't get there but I am really gonna try.

    Oh by the way I went from obese to overweight then back to obese bmi just this week but I am working on it.
  • The_Original_Beauty
    The_Original_Beauty Posts: 162 Member
    Packerjohn wrote: »
    For my 7 year old it is completely pointless. She is a gymnast and trains 8 hours a week, full on training. She has a lot of muscle, she has no fat on her at all, a six pack yet her BMI is close to being overweight?

    Was the doctor, who I assume was personally examining her, concerned that she was close to overweight? If not, then like 10% of some of adults she is somewhat of an outlier i.e., people with significantly more muscle mass than normal and the charts aren't relevant for her.

    No he just looked at her and was completely surprised...it really threw him, simply because he could not believe it!!!

  • Wheelhouse15
    Wheelhouse15 Posts: 5,575 Member
    Packerjohn wrote: »
    For my 7 year old it is completely pointless. She is a gymnast and trains 8 hours a week, full on training. She has a lot of muscle, she has no fat on her at all, a six pack yet her BMI is close to being overweight?

    Was the doctor, who I assume was personally examining her, concerned that she was close to overweight? If not, then like 10% of some of adults she is somewhat of an outlier i.e., people with significantly more muscle mass than normal and the charts aren't relevant for her.

    No he just looked at her and was completely surprised...it really threw him, simply because he could not believe it!!!

    Then he should have known that she was very muscular. I can't believe a doctor has no experience with child athletes and doesn't understand the difference even a bit more muscle can make for children.
  • trigden1991
    trigden1991 Posts: 4,658 Member
    neldabg wrote: »
    Back in high school, a friend of mine pointed out to me that the kids in my school who opposed P.E (gym class) the most were overweight.
    Imo, the same applies here. Those who denounce the BMI chart the loudest tend to be overweight. Also good to notice that very often, BMI is oh-so-accurate if someone mentions that they're even one pound underweight, but if someone is one pound or more overweight, it's okay because screw BMI calculations. :)
    Bottom line, BMI, as many have already written here, is generally accurate enough for the masses.

    I am "obese" according to the BMI charts however I am under 15% bodyfat. The charts aren't good for people who are athletic, undertake resistance training, are very short or very tall.
  • Wheelhouse15
    Wheelhouse15 Posts: 5,575 Member
    neldabg wrote: »
    Back in high school, a friend of mine pointed out to me that the kids in my school who opposed P.E (gym class) the most were overweight.
    Imo, the same applies here. Those who denounce the BMI chart the loudest tend to be overweight. Also good to notice that very often, BMI is oh-so-accurate if someone mentions that they're even one pound underweight, but if someone is one pound or more overweight, it's okay because screw BMI calculations. :)
    Bottom line, BMI, as many have already written here, is generally accurate enough for the masses.

    I am "obese" according to the BMI charts however I am under 15% bodyfat. The charts aren't good for people who are athletic, undertake resistance training, are very short or very tall.

    What are you stats? You certainly don't look like you would be obese from you PP.
  • neldabg
    neldabg Posts: 1,452 Member
    neldabg wrote: »
    Back in high school, a friend of mine pointed out to me that the kids in my school who opposed P.E (gym class) the most were overweight.
    Imo, the same applies here. Those who denounce the BMI chart the loudest tend to be overweight. Also good to notice that very often, BMI is oh-so-accurate if someone mentions that they're even one pound underweight, but if someone is one pound or more overweight, it's okay because screw BMI calculations. :)
    Bottom line, BMI, as many have already written here, is generally accurate enough for the masses.

    I am "obese" according to the BMI charts however I am under 15% bodyfat. The charts aren't good for people who are athletic, undertake resistance training, are very short or very tall.

    ... Please reread my last sentence.
  • robininfl
    robininfl Posts: 1,137 Member
    I hate the WHR method. I have narrow hips, so no matter how slim I get, I am always considered "at risk." :(

    Waist to HEIGHT, mousepotato, not just waist to hip. When you are a slender build, waist to hip doesn't really work well. Waist to height should work. My waist to hip ratio is never *great* because I'm built pretty much straight up and down. The sleeker built you are, the worse this ratio will look.
  • neldabg
    neldabg Posts: 1,452 Member
    tomteboda wrote: »
    neldabg wrote: »
    Back in high school, a friend of mine pointed out to me that the kids in my school who opposed P.E (gym class) the most were overweight.
    Imo, the same applies here. Those who denounce the BMI chart the loudest tend to be overweight. Also good to notice that very often, BMI is oh-so-accurate if someone mentions that they're even one pound underweight, but if someone is one pound or more overweight, it's okay because screw BMI calculations. :)
    Bottom line, BMI, as many have already written here, is generally accurate enough for the masses.

    If you look at the morbidity and mortality risks of being underweight, this would make a lot more sense. The risks of being underweight are acute and profound, and rise precipitously with dropping BMI. In fact, the risks start accelerating below at BMI of 21 and exceed that of people with Class II obesity. Below 18.5 they exceed that of Class III obesity and rise dramatically.

    Here is a fairly sound review that is easily understood and available at no charge

    Nuttall, Frank Q. "Body Mass Index: Obesity, BMI, and Health: A Critical Review." Nutrition today 50.3 (2015): 117-128.



    Nice! You're the first person on MFP I've encountered who explained to me why people may worry more for the one-pound-underweight person instead of the five-pounds-overweight person. Thanks the link! It was a good read.
    However, I don't see where in the link it supported that a BMI under *21* had health risks greatly exceeding that of people with Class II obesity, enough to warrant worry. The focus and the conclusion written is that "being a bit overweight (preobese?) as determined by BMI may not be so bad." The journal writer does link an EPIC Observational Study about diabetes where a lower BMI was associated with a higher risk, but as was similar in other linked studies looking at BMI (like the General and Abdominal Adiposity and Risk of Death in Europe study), "circumference affected the mortality rate negatively" and lifestyle choices seemed to be another important factor. In other words, what I'm seeing being concluded is that from both ends of the BMI, the risks may not necessarily be something to be deeply concerned with when other factors, especially waist circumference, are taken into account.
  • cwolfman13
    cwolfman13 Posts: 41,879 Member
    For my 7 year old it is completely pointless. She is a gymnast and trains 8 hours a week, full on training. She has a lot of muscle, she has no fat on her at all, a six pack yet her BMI is close to being overweight?

    If she's close to overweight, but not overweight, it would just mean she's at the high end of BMI...being at the high end of BMI doesn't mean your fat...so I fail to see how it's pointless.

    Beyond that, it's just one of many tools that should be utilized in addressing one's health.

    I personally am overweight by BMI (just slightly)...but I'm at a healthy BF%...right now I'm around 16ish%...which certainly means that I'm not over fat, but it's not like I couldn't lose a bit of fat and get into the high end of my BMI either.

    I think it's fairly applicable to the vast majority of people...but like I said, only one of many tools that should be utilized.