BMI - how much do you depend on your BMI #

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Replies

  • toddis
    toddis Posts: 941 Member
    I dislike how the outliers say the whole scheme is broke because of them. Not everyone is an outlier. As it's already been said, it's a tool for measuring populations and really shouldn't be applied strictly to individuals.

    That being said, a long time ago, when I was in the military BMI was used to calculate weight allowances. You could get an exception if you got tested and proved it was muscle. I never met someone with an exception.
  • paulbuxton
    paulbuxton Posts: 12 Member
    I think I'm going to have to state the facts about BMI since I am a Registered Dietitian and Nutritionist. The DEFINITION of Body mass index (BMI) is a measure of BODY FAT based on height and weight that applies to adult men and women. While it does have its limitations, it is a useful tools to measure underweight, healthy weight, Overweight or obese status in individuals who are not bodybuilders or athletes.

    That being said, BMI also does not differentiate between body fat and muscle mass. This may often result in misleading information with regard to the amount of fat in an individual. There is a potential risk of overestimating ‘fatness’ in individuals with high muscle mass, such as body-builders, and underestimating the fat deposit in those with less lean body mass, such as the elderly.

    In Healthcare settings, BMI is used it is part of the Nutritional Assessment of a patient/resident and for Medical billing purposes in the United States. I am just stating the facts here, as I use it everyday at my job. If the Patient/Resident is determined to be either underweight, overweight or obese based on weight and height alone, I must code for that. There are no exceptions.

    I am 5'1" and 102-103 lb = BMI of 19.3-19.5 (Healthy Weight), I workout 6 days per week and lift weights 3x per week, but not heavy and I'm not a body builder. Personally, I am more concerned about my body fat percentage and amount of lean body mass I have.

    Therefore, while BMI can be a useful health tool in many individuals it is not a useful in Body Builders and Athletes, esp. in Males who lift heavy weights, they will almost always be labeled as Overweight or Obese. Again BMI does not differentiate between fat mass and muscle mass. Better indicators for fitness level would be Body Fat %, Waist Circumference and Waist to Hip Ratio. Also go by how you look in the mirror and how you fit in your clothes.

    Great link below on the Limitations of BMI and Calculating BMI

    http://www.medindia.net/patients/patientinfo/body-mass-index-limitations.htm

    http://www.nhlbi.nih.gov/health/public/heart/obesity/lose_wt/risk.htm

    Waist to Hip Ratio Calculator

    http://www.bmi-calculator.net/waist-to-hip-ratio-calculator/

    :flowerforyou:

    Thanks Coach Reddy. I'm glad you agree. :happy:

    I confess to being a little confused with your post. You mention that you consider it a good indicator, and that in your job you have to apply it strictly as defined. But then provide links that talk about the drawbacks. One of my concerns if it has these drawbacks then you need to know you are in one of these groups to be able to know to either use another measure or apply a correction, and if there are other better measures (like body fat%) then why not use them instead?

    Just to be a little bit pedantic BMI is not a measure of fat based on weight and height, it is an estimate, which is really the problem with it, it is very wide bell curve. Using the graph here as an example.
    http://upload.wikimedia.org/wikipedia/commons/b/b7/Correlation_between_BMI_and_Percent_Body_Fat_for
    _Men_in_NCHS%27_NHANES_1994_Data.PNG

    My current bodyfat is about 23% which could be anything between a BMI of about 19 to 32, my actual BMI is 29.8. I am not especially muscular. If I keep my current lean mass of 72Kg and get to 15% bodyfat (which is about where you start to show a sixpack) I will still have a BMI of about 27.5 i.e. overweight. Yet as far as my build etc I would say I was no more than average.

    Nice to have a professionals view on it!
  • DrMAvDPhD
    DrMAvDPhD Posts: 2,097 Member
    My current bodyfat is about 23% which could be anything between a BMI of about 19 to 32, my actual BMI is 29.8. I am not especially muscular. If I keep my current lean mass of 72Kg and get to 15% bodyfat (which is about where you start to show a sixpack) I will still have a BMI of about 27.5 i.e. overweight. Yet as far as my build etc I would say I was no more than average.

    For a male your body fat % is on the high end of average (18-24) and you likely wouldn't start to show abs until sub 13%. I think you are confusing male and female body fat percent ideals.

    ETA It is also pretty much impossible to maintain ALL your lean body mass as you lose weight, even if you eat right and lift. So you would end up at a lower weight to get to the 13-15% range anyway.
  • SpeSHul_SnoflEHk
    SpeSHul_SnoflEHk Posts: 6,256 Member
    I dislike how the outliers say the whole scheme is broke because of them. Not everyone is an outlier. As it's already been said, it's a tool for measuring populations and really shouldn't be applied strictly to individuals.

    That being said, a long time ago, when I was in the military BMI was used to calculate weight allowances. You could get an exception if you got tested and proved it was muscle. I never met someone with an exception.

    Apparently it depends on the military. In the Navy, we used BF% as measured by circumfernces of waist hip and neck as I mentioned in a previous post.

    I think a lot of the issue here is that this is a fitness related website, and as such, you are going to have a higher than normal number of outliers here who will take offense to the BMI being used as an indicator of health and fitness. It's like going to the Democratic Party National Convention, and surveying all attendees about Obama's approval rating, and then reporting to the nation that Obama has a 97% approval rating. Too much bias here for this argument.
  • titanbonnie
    titanbonnie Posts: 37
    No one should ever go by BMI. It's not an accurate way to measure yourself! I am 130lbs all muscle and by BMI it says I am Obese! No way jose! You need to take into consideration how much fat/muscle/height ect a person has.
  • titanbonnie
    titanbonnie Posts: 37
    I get it, I played quads for many years! My legs are like thors
  • GracefulDancer4Christ
    GracefulDancer4Christ Posts: 419 Member
    I feel the bmi is way off you are by no means overweight. their criteria for what is considered overweight is very unrealistic.
    they would consider a body builder obese so i really don't put much stock in it. incidently according to the bmi the nurse at my daughter's school considered my daughter over weight at 4"9 inches tall and 90 pounds.
  • Kekibird
    Kekibird Posts: 1,122 Member
    I don't rely on the BMI chart at all. I go by feeling, measurements and before/after pictures. I don't even really trust a scale much since mine isn't moving but my pants are fitting better and my running has improved.
  • aliciagetshealthy
    aliciagetshealthy Posts: 946 Member
    The only reason I pay any attention to it at all is because my insurance company does.
  • suzieqsmart
    suzieqsmart Posts: 47
    BMI is crap.

    In my opinion, it's because of the BMI charts that people have eating disorders. They are so obsessed with a random # that they can't see with their own eyes that their body looks good.

    I agree! According to the BMI charts the "TOP" end of my "healthy" weight range is 160lbs. However, my goal weight is 155-160 and I think I would start to look pretty scrawny if I aimed for the 140 that BMI would suggest. I have an athletic body type, very muscular legs and bigger bones.

    Yes, I know what some people might say about "big boned" but it's true. My cousin and I eat healthy and work out together. Even when we're both fit beyond belief, she is always smaller than me and about 10lbs lighter than me. Her rib cage is probably 3 inches smaller than mine but we're the same height. It's just the way I'm built. Thus, the BMI charts would probably put me at borderline "overweight" when, in fact, I'm right on target and very healthy.
  • JeneticTraining
    JeneticTraining Posts: 663 Member
    BMI is just a generalization. I really do not depend on it. I eat at my BMR + calories I burned that day via cardio.
  • neacail
    neacail Posts: 228 Member
    My BMI is incredibly important to decisions my physician and I are making in regards to my health, wellness, and the approach to treating my arthritis.
  • pghlulu
    pghlulu Posts: 42
    I think the funniest part of this thread are the responses calling BMI useless, but following it up with "my pants size is..."

    because THAT is certainly an indicator of healthy weight. :laugh:

    It directly correlates to waist size which actually is in indication of health. So -- not sure why that is hilarious, but um yeah. Yes, sizes vary -- but if you are a size 10 US your waist is likely 27-29.

    Sorry, but I don't think that's very accurate....I wear a 0-2 US and my waist is 25.5. I wore a size 4 US 2 years ago when my waist was 29. Nothing close to a size 10. Waist inches, pants size (which can vary even within one department store), BMI, etc. - none of these singular things give an accurate picture of a person's overall actual body composition.

    *edited for clarity
  • RitaB19
    RitaB19 Posts: 221 Member
    I think I'm going to have to state the facts about BMI since I am a Registered Dietitian and Nutritionist. The DEFINITION of Body mass index (BMI) is a measure of BODY FAT based on height and weight that applies to adult men and women. While it does have its limitations, it is a useful tools to measure underweight, healthy weight, Overweight or obese status in individuals who are not bodybuilders or athletes.

    That being said, BMI also does not differentiate between body fat and muscle mass. This may often result in misleading information with regard to the amount of fat in an individual. There is a potential risk of overestimating ‘fatness’ in individuals with high muscle mass, such as body-builders, and underestimating the fat deposit in those with less lean body mass, such as the elderly.

    In Healthcare settings, BMI is used it is part of the Nutritional Assessment of a patient/resident and for Medical billing purposes in the United States. I am just stating the facts here, as I use it everyday at my job. If the Patient/Resident is determined to be either underweight, overweight or obese based on weight and height alone, I must code for that. There are no exceptions.

    I am 5'1" and 102-103 lb = BMI of 19.3-19.5 (Healthy Weight), I workout 6 days per week and lift weights 3x per week, but not heavy and I'm not a body builder. Personally, I am more concerned about my body fat percentage and amount of lean body mass I have.

    Therefore, while BMI can be a useful health tool in many individuals it is not a useful in Body Builders and Athletes, esp. in Males who lift heavy weights, they will almost always be labeled as Overweight or Obese. Again BMI does not differentiate between fat mass and muscle mass. Better indicators for fitness level would be Body Fat %, Waist Circumference and Waist to Hip Ratio. Also go by how you look in the mirror and how you fit in your clothes.

    Great link below on the Limitations of BMI and Calculating BMI

    http://www.medindia.net/patients/patientinfo/body-mass-index-limitations.htm

    http://www.nhlbi.nih.gov/health/public/heart/obesity/lose_wt/risk.htm

    Waist to Hip Ratio Calculator

    http://www.bmi-calculator.net/waist-to-hip-ratio-calculator/

    :flowerforyou:

    Thanks Coach Reddy. I'm glad you agree. :happy:

    I confess to being a little confused with your post. You mention that you consider it a good indicator, and that in your job you have to apply it strictly as defined. But then provide links that talk about the drawbacks. One of my concerns if it has these drawbacks then you need to know you are in one of these groups to be able to know to either use another measure or apply a correction, and if there are other better measures (like body fat%) then why not use them instead?

    Just to be a little bit pedantic BMI is not a measure of fat based on weight and height, it is an estimate, which is really the problem with it, it is very wide bell curve. Using the graph here as an example.
    http://upload.wikimedia.org/wikipedia/commons/b/b7/Correlation_between_BMI_and_Percent_Body_Fat_for
    _Men_in_NCHS%27_NHANES_1994_Data.PNG

    My current bodyfat is about 23% which could be anything between a BMI of about 19 to 32, my actual BMI is 29.8. I am not especially muscular. If I keep my current lean mass of 72Kg and get to 15% bodyfat (which is about where you start to show a sixpack) I will still have a BMI of about 27.5 i.e. overweight. Yet as far as my build etc I would say I was no more than average.

    Nice to have a professionals view on it!

    Your welcome! I gave you the exact definition straight from the website. Not my own. And yes, its an estimate. I wouldn't obsess over BMI. If you are eating healthy and exercising regularly your body will naturally slim down to a healthier weight. Not everyone has access to getting their body fat measured. In addition, some methods have a high degree of error. If you Body Fat got down to 15%, there is no way you would be overweight. Again BMI is not useful in bodybuilders and athletes. BMI Percentiles are also used in schools to assess if children's weight and health status.
  • mlcrruth
    mlcrruth Posts: 10
    I rely on it, not much, but I do.

    One thing I hate is those generic body fat electric calculators. Especially the hand held ones. They show me to be around 10% body fat. NOWHERE CLOSE to what I really am. I wish I actually could give myself a decent body fat guestimate. My arms and legs dont have much fat. Im guessing that is why the handheld does not read right.

    One thing I did like on bb.com was the body fat estimation thread.

    Would it be worth starting that here?

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