Is BMI an accurate way to know how much I should weigh?
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I am partial to the waist to height ration. As long as your waist is at most 50% of your height you are doing ok. Lower the better, within reason...3
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azalea4175 wrote: »what if you have large dense bones and dense tissue? i continually have issues with MRI's, etc. because my tissue is "dense" (their word, not mine) and my wrist bone is over 8" in size. I'm built like my short stocky Italian grandfather. I don't believe the typical BMI chart would be accurate. How else do we measure bodyfat?
Bone density is a great thing in a woman: Congratulations! (I wish mine were denser . . . .). I don't have the stats at my fingertips, but weight of the skeleton doesn't differ a lot across people of the same height, so also isn't a huge factor in ideal body weight. The reason is math-y, in two ways.
First, bones only account for around 12-14% of body weight, on average. Most of the weight is something else. Second, body geometry is pretty important. An easy example: Consider a woman with widely-spaced pelvic bones, vs. a woman with very narrow pelvic width. The first woman may have somewhat more pelvic bone weight, but the bigger factor is the geometrically greater volume of muscle, blood vessels, skin, blood, etc., that it takes to enclose that bigger space.
As an aside, I feel like wrists, considered alone, can be misleading: I have big wrists and hands, but narrow hips, and am good around BMI 20-21, which is low-middle normal.
Sure, if you have a wider build, you'll tend to fall a little higher in the BMI range at your ideal weight, vs. someone who's more narrow and overall delicate-looking. But it's pretty unusual for a woman to be so stocky skeletally so as to be above the normal BMI range: Keep in mind that the same range covers both men and women, and the average woman tends to be at a good weight somewhere lower on that scale than the average man. Possible? Sure. Hard to tell, though.
You're on a good track, thinking about body fat percent. There are sites with photos of example people you can compare yourself to visually, and folks above have mentioned other estimation methods for body fat. There are scans you can pay for ($$$) to get fairly accurate readings (like DEXA). Elsewhere in the thread, people have talked about screening metrics other than body fat, like waist size, waist to height ratio, etc. Then there's the "talk with your doctor" option, which although not definitive, is very personalized, and sensitive to your personal and familial health history.5 -
Is a bmi of 29 very far out of the healthy range? We're talking about a difference of 25lbs, about what a man can gain in muscle mass with a year of training.
For a man to gain 25 pounds of muscle in a year it would take the training and diet of D1 football player. Most of the guys at the gym on the curl machine taking selfies don't fit that bill.8 -
azalea4175 wrote: »what if you have large dense bones and dense tissue? i continually have issues with MRI's, etc. because my tissue is "dense" (their word, not mine) and my wrist bone is over 8" in size. I'm built like my short stocky Italian grandfather. I don't believe the typical BMI chart would be accurate. How else do we measure bodyfat?
There is a 30-40 pound range of "normal" at most heights so very few unicorns out there unless one has been on a long term weight lifting (or heavy manual labor) regime.8 -
Getting a bod pod is the way to go in order to understand how much of your body weight is fat. Height/weight ratios are pretty worthless. IMO, anyway. I only pay $40 for a bod pod test and it shows me every 6-8 weeks how much fat I’ve lost and how much lean muscle mass was gained. What good is losing 15 pounds if 10 of those are muscle mass? I yo-yo’d a lot with losing muscle mass whenever I lost weight until I started using that testing method.1
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you are paying $40 every 6 - 8 weeks for this?
For most people height / weight ratios ( which is what BMI is) give a good idea of whether you are a healthy weight - as whole last page or so has pointed out.
Something you can work out for free.
I'll save my money, thanks.5 -
Liftsalotat5 wrote: »Getting a bod pod is the way to go in order to understand how much of your body weight is fat. Height/weight ratios are pretty worthless. IMO, anyway. I only pay $40 for a bod pod test and it shows me every 6-8 weeks how much fat I’ve lost and how much lean muscle mass was gained. What good is losing 15 pounds if 10 of those are muscle mass? I yo-yo’d a lot with losing muscle mass whenever I lost weight until I started using that testing method.
Be aware the test is not for body fat vs lean muscle mass.
That is common confusion over the term used Lean Body Mass (LBM).
That is merely EVERYTHING that is not Fat Mass (FM).
Muscles, bones, organs, and water weight. All part of LBM.
You drink 16 oz of water you just gained 1 lb of LBM.
You go in slightly dehydrated you just lost 1 lb of LBM.
And obviously nothing with muscle was involved.
There is literally no such thing as lean muscle mass unless getting a cut of meat from the butcher - your genetics and type of workouts will determine how much fat is actually in the muscle.
But yes - Bodypod nice cheap accurate enough option if curious - buy a package deal most places too.2 -
Don't waste your money on bod pod nonsense. If you want to know wether you are losing muscle from dieting take a neck measurement...1
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paperpudding wrote: »you are paying $40 every 6 - 8 weeks for this?
For most people height / weight ratios ( which is what BMI is) give a good idea of whether you are a healthy weight - as whole last page or so has pointed out.
Something you can work out for free.
I'll save my money, thanks.
Outside of some special cases, I feel like if one is eating a reasonable amount of calories, incorporating resistance training, and getting sufficient protein, paying for regular body scans is overkill. For most people, doing this is going to eliminate the possibility of losing too much muscle.4 -
BMI, taking only height and weight into account, is a poor indicator of body composition when compared to methods of determining body fat percentage. It's primary appeal is how easy it is to ascertain.
The problem with BMI is that it ignores that there are different body types (e.g. ectomorph, endomorph, mesomorph), and it has only a very generalized correlation with lean body mass. Body fat percentage is a much better indicator but also much harder to ascertain (and also greater margin of error and differing outcomes depending on method used). There are methods that rely on caliper measurements (with varying number of measuring points), body circumference measurements, bioelectrical impedance, Bod Pod, DEXA,...
Each of these methods will provide a body fat percentage with some margin of error.
I have no desire or hope to achieve a BMI in the "Normal" range (for 6'1", 189 lbs. is the top end of "Normal"). I weighed 218 at age 35 and was running 2 miles a day and working out. I'm sure I could have lost some of that weight, but not 29 lbs.
I know I am overweight, but I also know that, at 6'1", a goal weight of 140.2-189.5 pounds is out of the question. My current lean body mass (as measured by a Withings Body+ scale) is around 160 lbs and trending up, and my present weight is 286 lbs.
I had a DEXA scan on Sept 30th of this year, and the results of that were:
weight: 305 lbs;
body fat percentage: 44.5%;
fat tissue: 135.6 lbs;
lean tissue: 159.9 lbs
bone mineral content: 9.5 lbs
BMI is fine if you have no other option, but don't take it too seriously. I plan on relying on the results of DEXA scans because they aren't too expensive and there is a facility close enough. I'll probably have a couple more scans between now and next July 10th when I hope to make my goal of 230 lbs. At that point, the DEXA scan will tell me if I should continue losing weight or start maintaining.
(a Withings Body+ or similar scale is worth considering)
What Ways Are There to Measure Body Fat?
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I have no desire or hope to achieve a BMI in the "Normal" range (for 6'1", 189 lbs. is the top end of "Normal"). I weighed 218 at age 35 and was running 2 miles a day and working out. I'm sure I could have lost some of that weight, but not 29 lbs.
So you were a tall young sporty male and you had a bmi of 28
That's what I said before - sporty young men having a BMI slightly over the upper cut off whilst being at a healthy weight.
I don't think so called endomorph etc body types changes the fact that almost everybody, barring obvious outliers, will be at a healthy weight somewhere in, or in some cases, slightly out of, the standard charts.2 -
paperpudding wrote: »I have no desire or hope to achieve a BMI in the "Normal" range (for 6'1", 189 lbs. is the top end of "Normal"). I weighed 218 at age 35 and was running 2 miles a day and working out. I'm sure I could have lost some of that weight, but not 29 lbs.
So you were a tall young sporty male and you had a bmi of 28
That's what I said before - sporty young men having a BMI slightly over the upper cut off whilst being at a healthy weight.
I don't think so called endomorph etc body types changes the fact that almost everybody, barring obvious outliers, will be at a healthy weight somewhere in, or in some cases, slightly out of, the standard charts.
Sure, BMI is good for a lot of people. But why rely on a metric that only considers height and weight? Why not try, e.g. the Navy's method of estimating body fat percentage? It uses gender, height, weight, waist circumference, hip circumference (for women), and neck circumference. All easy to do. Just my opinion.
Navy's Fat Percentage Calculator1 -
Yeah BMI says nothing about body fat levels, the data seems to confirm this. Just take a look at this study :
https://www.sciencedaily.com/releases/2017/06/170606090942.htm#:~:text=2-,Waist-to-height ratio more accurate than BMI in,identifying obesity, new study shows&text=Summary:,practice, a new study shows.
"The researchers, led by Dr Michelle Swainson, Senior Lecturer in Exercise Physiology in the Carnegie School of Sport at Leeds Beckett, found that 36.5% more adults would be classified as obese using whole-body fat data (one in two participants) rather than body mass index (BMI) (around one in seven participants, or 13.5%)."
"BMI had weak support as a predictor for whole-body fat percentage in both men and women but was a plausible alternative for the prediction of VAT mass in women."
Waist measurement is a pretty good indicator, especially for men, it's where we carry fat. If your waist is half your height, there is nothing to worry about.
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Yeah BMI says nothing about body fat levels, the data seems to confirm this. Just take a look at this study :
https://www.sciencedaily.com/releases/2017/06/170606090942.htm#:~:text=2-,Waist-to-height ratio more accurate than BMI in,identifying obesity, new study shows&text=Summary:,practice, a new study shows.
The researchers, led by Dr Michelle Swainson, Senior Lecturer in Exercise Physiology in the Carnegie School of Sport at Leeds Beckett, found that 36.5% more adults would be classified as obese using whole-body fat data (one in two participants) rather than body mass index (BMI) (around one in seven participants, or 13.5%).
BMI had weak support as a predictor for whole-body fat percentage in both men and women but was a plausible alternative for the prediction of VAT mass in women.
Waist measurement is a pretty good indicator, especially for men, it's where we carry fat. If your waist is half your height, there is nothing to worry about.
That's a good point. While one can argue that some healthy people (outliers) will have a BMI that puts them in the obese category, it is equally true that there will be people who are obese yet fall within the healthy BMI range.1 -
frankwbrown wrote: »paperpudding wrote: »I have no desire or hope to achieve a BMI in the "Normal" range (for 6'1", 189 lbs. is the top end of "Normal"). I weighed 218 at age 35 and was running 2 miles a day and working out. I'm sure I could have lost some of that weight, but not 29 lbs.
So you were a tall young sporty male and you had a bmi of 28
That's what I said before - sporty young men having a BMI slightly over the upper cut off whilst being at a healthy weight.
I don't think so called endomorph etc body types changes the fact that almost everybody, barring obvious outliers, will be at a healthy weight somewhere in, or in some cases, slightly out of, the standard charts.
Sure, BMI is good for a lot of people. But why rely on a metric that only considers height and weight? Why not try, e.g. the Navy's method of estimating body fat percentage? It uses gender, height, weight, waist circumference, hip circumference (for women), and neck circumference. All easy to do. Just my opinion.
Navy's Fat Percentage Calculator
Nothing wrong with the Navy method or the waist to height ratio. Just remember if someone is showing up as overweight or obese on BMI they are most likely overfat on the other measures mentioned.5 -
frankwbrown wrote: »...
Sure, BMI is good for a lot of people. But why rely on a metric that only considers height and weight? Why not try, e.g. the Navy's method of estimating body fat percentage? It uses gender, height, weight, waist circumference, hip circumference (for women), and neck circumference. All easy to do. Just my opinion.
I don't know what I said in the above quote that prompted several people to click Disagree.
Do you disagree that "BMI is good for a lot of people"?
Do you disagree with my suggestion to try the Navy method? Or that it's "easy to do"?
My problem with BMI is that in order to cover most people, it has to have a fairly broad range of BMI categorized as Normal. It is flawed logic to think this only results in some "outliers" appearing to be overweight (or underweight). Those that are "outliers" would include not only those who are normal but fall outside the normal BMI range, but also those who are not normal but appear to be, i.e. too fat but have a normal BMI, or too skinny but have a normal BMI.
I knew a woman years ago that clearly had a self-image problem (probably had anorexia). I wonder if her BMI did or would have told her she's in the underweight category. Hopefully so.
So disagree as you will, but I don't care much for BMI, and as Shakespeare said in Much Ado About Nothing, it is an "opinion that fire cannot melt out of me. I will die in it at the stake."
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Liftsalotat5 wrote: »Getting a bod pod is the way to go in order to understand how much of your body weight is fat. Height/weight ratios are pretty worthless. IMO, anyway. I only pay $40 for a bod pod test and it shows me every 6-8 weeks how much fat I’ve lost and how much lean muscle mass was gained. What good is losing 15 pounds if 10 of those are muscle mass? I yo-yo’d a lot with losing muscle mass whenever I lost weight until I started using that testing method.
Where does one find a "bod pod"? I am pretty sure such a thing is not available to us....have I mentioned I live practically at the end of the earth in Maine? 2 -
frankwbrown wrote: »frankwbrown wrote: »...
Sure, BMI is good for a lot of people. But why rely on a metric that only considers height and weight? Why not try, e.g. the Navy's method of estimating body fat percentage? It uses gender, height, weight, waist circumference, hip circumference (for women), and neck circumference. All easy to do. Just my opinion.
I don't know what I said in the above quote that prompted several people to click Disagree.
Do you disagree that "BMI is good for a lot of people"?
Do you disagree with my suggestion to try the Navy method? Or that it's "easy to do"?
My problem with BMI is that in order to cover most people, it has to have a fairly broad range of BMI categorized as Normal. It is flawed logic to think this only results in some "outliers" appearing to be overweight (or underweight). Those that are "outliers" would include not only those who are normal but fall outside the normal BMI range, but also those who are not normal but appear to be, i.e. too fat but have a normal BMI, or too skinny but have a normal BMI.
I knew a woman years ago that clearly had a self-image problem (probably had anorexia). I wonder if her BMI did or would have told her she's in the underweight category. Hopefully so.
So disagree as you will, but I don't care much for BMI, and as Shakespeare said in Much Ado About Nothing, it is an "opinion that fire cannot melt out of me. I will die in it at the stake."
The very nature of BMI is that it is based on population level information and it's providing a general guideline on the health risks associated with different weight ranges. It isn't meant to be an absolute and holistic guide to an individual's weight. The very stuff you have a "problem" with is inherent to the tool itself. It's like having a problem with an actuarial table because it failed to predict the exact date of someone's death.
I didn't "disagree" with your post, but it's possible that some people did on that basis.
Nobody is saying that BMI is going to only result in some outliers appearing to be over- or underweight and that everyone in the "normal" range is at their perfect weight. I think we've even had people in this very thread point out that they personally consider themselves to be overweight at the upper ranges of the normal weight for their height (I am one of these people), as well as those who consider themselves to be underweight at the lower ends of the normal range for their height.
What's weird about this topic is that so many people seem to misunderstand what BMI is meant to convey. It's a guide as to when it might be worth paying attention to whether one is over or underweight, but not an absolute diagnostic of that state on an individual level. Some people will need additional tools to help them understand. It is also a guide that can help one understand if one is within the range of weight that isn't associated with weight related health issues on a population level, but it isn't a guarantee that one is at an ideal weight any more than I can look at the life expectancy for a 41-year-old and know for sure that I'll be here this time next year.
For most people, BMI is going to be a pretty good guide to the risk associated with their current weight. But there are always going to be people who aren't "most people," whether we're talking about BMI, life expectancy, or things like blood test results.9 -
@janejellyroll
The OP said (emphasis mine):
I understand the roll BMI is meant to play, and that it is not the be all and end all of determining body health. No method is that, although some are better than others. But given what the OP said in opening this thread, It seems misplaced for some to be defending BMI rather than advising the OP to look for other measures. Thus, my comments.nonachalke wrote: »I looked up my BMI last night and it says I’m overweight, so obviously I’m freaking out. But is it accurate? I don’t want to just lose weight, I want to get toned and strong, I like muscle on me, but how do I know how much I should weigh?!
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janejellyroll wrote: »frankwbrown wrote: »frankwbrown wrote: »...
Sure, BMI is good for a lot of people. But why rely on a metric that only considers height and weight? Why not try, e.g. the Navy's method of estimating body fat percentage? It uses gender, height, weight, waist circumference, hip circumference (for women), and neck circumference. All easy to do. Just my opinion.
I don't know what I said in the above quote that prompted several people to click Disagree.
Do you disagree that "BMI is good for a lot of people"?
Do you disagree with my suggestion to try the Navy method? Or that it's "easy to do"?
My problem with BMI is that in order to cover most people, it has to have a fairly broad range of BMI categorized as Normal. It is flawed logic to think this only results in some "outliers" appearing to be overweight (or underweight). Those that are "outliers" would include not only those who are normal but fall outside the normal BMI range, but also those who are not normal but appear to be, i.e. too fat but have a normal BMI, or too skinny but have a normal BMI.
I knew a woman years ago that clearly had a self-image problem (probably had anorexia). I wonder if her BMI did or would have told her she's in the underweight category. Hopefully so.
So disagree as you will, but I don't care much for BMI, and as Shakespeare said in Much Ado About Nothing, it is an "opinion that fire cannot melt out of me. I will die in it at the stake."
The very nature of BMI is that it is based on population level information and it's providing a general guideline on the health risks associated with different weight ranges. It isn't meant to be an absolute and holistic guide to an individual's weight. The very stuff you have a "problem" with is inherent to the tool itself. It's like having a problem with an actuarial table because it failed to predict the exact date of someone's death.
I didn't "disagree" with your post, but it's possible that some people did on that basis.
Nobody is saying that BMI is going to only result in some outliers appearing to be over- or underweight and that everyone in the "normal" range is at their perfect weight. I think we've even had people in this very thread point out that they personally consider themselves to be overweight at the upper ranges of the normal weight for their height (I am one of these people), as well as those who consider themselves to be underweight at the lower ends of the normal range for their height.
What's weird about this topic is that so many people seem to misunderstand what BMI is meant to convey. It's a guide as to when it might be worth paying attention to whether one is over or underweight, but not an absolute diagnostic of that state on an individual level. Some people will need additional tools to help them understand. It is also a guide that can help one understand if one is within the range of weight that isn't associated with weight related health issues on a population level, but it isn't a guarantee that one is at an ideal weight any more than I can look at the life expectancy for a 41-year-old and know for sure that I'll be here this time next year.
For most people, BMI is going to be a pretty good guide to the risk associated with their current weight. But there are always going to be people who aren't "most people," whether we're talking about BMI, life expectancy, or things like blood test results.
I think the individual confusion on how useful or meaning of BMI is because of how it's presented now.
Dr says your BMI is good or bad, sadly without more context or comments and patient without knowledge doesn't ask for clarification or challenge it.
Insurance companies doing some basis of health rates on BMI in some instances.
Articles about it, and I've seen many reference body fat as part of BMI.
Throw in blood tests that show perhaps cholesterol fine, and someone could think they are in great shape for little or no health issues, and actually be overfat and terrible cardio system.
I wouldn't be surprised if those just into overweight category BMI end up with a few more tests providing useful info.
Unless the Dr just says lose some weight and leaves it at that.
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