BMI - What it is and what its not!!

kapoorpk
kapoorpk Posts: 244 Member
in Fitness and Exercise
Reading through several posts, there seem to be a bit of misconception about BMI. I hope to offer some clarification below:

BMI is useful as a general tool to predict health risks. For example, a BMI of greater than 30 is labeled as obese and carries a high risk of heart desease, diabetes etc.

However, it does not distinguish one's fat, muscle and bone content, which is exactly what one needs to know to assess their level of wellness. One can have a BMI of 24 but be all fat and no muscle. Similarly, one can have a BMI of 28 and be all muscle and not much fat.

So, I recommend that when setting goals, its best to use BMI as a general guide but get a body fat/muscle measuring weigh scale. Most super stores like Target sell them. It can tell you your total body weight, body fat and body muscle percentage.

So, there is a risk in over-relying on just BMI when you may be totally off until you know your fat and muscle percentages.

The goal should be to aim for minimizing body fat percentage while maximizing the body muscle percentage.

Hope that helps.

Let me know of any comments.

Thanks

Replies

  • majorbaka
    majorbaka Posts: 23 Member
    Agree with you - it takes no account of muscularity etc.

    According to "BMI scales" at the gym I need to be between 56-76 kg.

    56 kg - think I'd be dead or applying as an extra for the next Pirates of the Caribbean movie!

    Even just relying on weight alone shouldn't be taken too seriously - thanks for the post.
  • notthatthis
    notthatthis Posts: 218
    minimising body fat and maximising body muscle percentage.

    Does that mean we are all to aim to be Ronnie Coleman? Or aim for 15% -25% body fat and then the LBM falls into place.

    Other than that, excellent point about BMI. Waist size I believe is now the favoured predictor, because that will really reflect the fat that surrounds vital organs.
  • Vailara
    Vailara Posts: 2,473 Member
    I've been using body fat scales but I do wonder how accurate they are. I've heard they are not very good?

    I wouldn't agree that "minimising body fat percentage" is always the best goal. I don't know if there's an advantage in having particularly low body fat.
  • notthatthis
    notthatthis Posts: 218
    I've been using body fat scales but I do wonder how accurate they are. I've heard they are not very good?

    I wouldn't agree that "minimising body fat percentage" is always the best goal. I don't know if there's an advantage in having particularly low body fat.

    I use tanita and they are good, as long as they are clean and on a very stable surface. If the figure frightens you then, how accurate do you want it to be. Me, I have gone from 41% to 27% BF% and that relates to the weight I have lost and muscle gained.
  • nexangelus
    nexangelus Posts: 2,080 Member
    Oh, this old chestnut...just hit the search function and all this has already been said oooh loads of times ; )
  • Vailara
    Vailara Posts: 2,473 Member
    I've been using body fat scales but I do wonder how accurate they are. I've heard they are not very good?

    I wouldn't agree that "minimising body fat percentage" is always the best goal. I don't know if there's an advantage in having particularly low body fat.

    I use tanita and they are good, as long as they are clean and on a very stable surface. If the figure frightens you then, how accurate do you want it to be. Me, I have gone from 41% to 27% BF% and that relates to the weight I have lost and muscle gained.

    I'd like it to be accurate partly because I'm trying to retain muscle so it's useful to know how much of what I've lost is fat. Some of the websites ask for body fat % in calculations (of BMR, etc.) so it's useful for that too. I had read that body fat scales aren't terribly accurate. I'm hoping that the figures are getting are somewhere within a few per cent, at least.

    Congratulations on your body recomposition!
  • notthatthis
    notthatthis Posts: 218
    Thank you

    As per accuracy, one mans accuracy is another mans missed by a mile. Are Body Comp Monitors as accurate as other methods, no. Are they highly inaccurate, no. They give you a very good working baseline.
  • 4mrunner
    4mrunner Posts: 6 Member
    There have been talks to do away with BMI due to how inaccurate it is, As others have stated, it does not take muscle into account, not friendly to athletes. Body-fat is still the best and only real way to know if you have too much fat on you.
  • kapoorpk
    kapoorpk Posts: 244 Member
    Oh, this old chestnut...just hit the search function and all this has already been said oooh loads of times ; )

    Is there anything that you can't Google in this day and age? This was restarted as it was being incorrectly referenced in recent conversations amongst a few. That's where this platform helps as it help clarify things for those that might need clarification.
    Thanks for your post.
  • kapoorpk
    kapoorpk Posts: 244 Member
    Reading through several posts, there seem to be a bit of misconception about BMI. I hope to offer some clarification below:

    BMI is useful as a general tool to predict health risks. For example, a BMI of greater than 30 is labeled as obese and carries a high risk of heart desease, diabetes etc.

    However, it does not distinguish one's fat, muscle and bone content, which is exactly what one needs to know to assess their level of wellness. One can have a BMI of 24 but be all fat and no muscle. Similarly, one can have a BMI of 28 and be all muscle and not much fat.

    So, I recommend that when setting goals, its best to use BMI as a general guide but get a body fat/muscle measuring weigh scale. Most super stores like Target sell them. It can tell you your total body weight, body fat and body muscle percentage.

    So, there is a risk in over-relying on just BMI when you may be totally off until you know your fat and muscle percentages.

    The goal should be to aim for minimizing body fat percentage while maximizing the body muscle percentage.

    Hope that helps.

    Let me know of any comments.

    Thanks

    Suggesting to minimize fat and maximize muscle within medically acceptable ranges only limited to our ability and preferences. No doubt, having more muscle than fat is extremely beneficial including improvements in metabolic rate, more energy and strength and an improved overall body performance. Regarding scales, the body fat/muscle measuring weight scale is the practical solution for most of us. They do have a known error rate of around +/- 8% but, if you use the machine consistently, you can focus on the progress it shows more on its absolute accuracy. Besides, the more accurate methods including calipers, under-water measuring, X-Rays etc. are not one can make part of your performance measurement daily at home trying to monitor progress towards goals. So, more of a practicality point about what can work in our busy daily lives.

    Thanks all for your comments.

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