"The graphic that reveals why BMI is useless?"

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Replies

  • yopeeps025
    yopeeps025 Posts: 8,680 Member
    yopeeps025 wrote: »

    That I feel is a sad statistic too. My original goal was to try to be 180 lb with 15% body fat at height 5'6.5. That didn't happen.

    What did happen? BMI chart says someone at 180 pounds measuring 5' 6.5" would be overweight by about 20 pounds. I cannot estimate your BFP without your waist measurement, though.
    I am curious how your case turned out.

    Well I don't know how much a DEXA scan would cost. I was still thinking of getting a bod pod done at 180. I'm 191 as of today. I might still do it just to see how much muscle mass I did lose. I will definitely post my results if I decide to in the forums. I hear too much that the bod pod is just as inaccurate as those scales.
  • yopeeps025
    yopeeps025 Posts: 8,680 Member
    senecarr wrote: »
    yopeeps025 wrote: »
    TR0berts wrote: »
    Um, nope. You only need height and weight.

    See? Even easier than you thought!

    Yeah, quick and easy. It's amazing to me how something that simple can give your very close estimates in the overwhelming majority of cases.

    During entrance processing for the military, they can use BMI to quickly separate most of the recruits into who is 'ready' and who needs a second look. I said previously, the 1 in 10 that needs a second look simply gets taped measured.

    That I feel is a sad statistic too. My original goal was to try to be 180 lb with 15% body fat at height 5'6.5. That didn't happen.
    At 5'6.5", if you maxed out the Fat Free Mass Index (about 25 for natural lifters), that would be 157 lb of lean body mass. It could take 10 years or so of lifting if you could hit, which would let you be ~15% body fat at ~184.

    I have been lifting for maybe 7-8 years of never being in a calorie deficit for more than a year of that.

  • yopeeps025 wrote: »

    Well I don't know how much a DEXA scan would cost. I was still thinking of getting a bod pod done at 180. I'm 191 as of today. I might still do it just to see how much muscle mass I did lose. I will definitely post my results if I decide to in the forums. I hear too much that the bod pod is just as inaccurate as those scales.


    I will have to research what those tests are---they are not familiar to me.

    This morning I had a friend measure around my belly (what the test refers to as 'waist') and plugged that number and my weight into an online calculator. Came to 18.5%.

    You have to measure at your belly-button, though. At 180 pounds, your belly would have to be at 33 inches to be at 15% body fat.
  • yopeeps025
    yopeeps025 Posts: 8,680 Member
    yopeeps025 wrote: »

    Well I don't know how much a DEXA scan would cost. I was still thinking of getting a bod pod done at 180. I'm 191 as of today. I might still do it just to see how much muscle mass I did lose. I will definitely post my results if I decide to in the forums. I hear too much that the bod pod is just as inaccurate as those scales.


    I will have to research what those tests are---they are not familiar to me.

    This morning I had a friend measure around my belly (what the test refers to as 'waist') and plugged that number and my weight into an online calculator. Came to 18.5%.

    You have to measure at your belly-button, though. At 180 pounds, your belly would have to be at 33 inches to be at 15% body fat.

    Yeah but the body distribution for fat is different for every person. Apparently I weigh as much as my brother does now. My lower body is way stronger and bigger than his. I had quad definition since I was like 230 lb. I always though that was weird. His upper body might be stronger than mine. His chest is way stronger than mine but its because he has trained it for at least 6 years longer. People now say I look smaller than he does.
  • I think body fat distribution is comparable enough between most people to make the estimates fairly close.
    There will always be outliers, but the majority will be close estimates.
  • senecarr
    senecarr Posts: 5,377 Member
    yopeeps025 wrote: »
    yopeeps025 wrote: »

    That I feel is a sad statistic too. My original goal was to try to be 180 lb with 15% body fat at height 5'6.5. That didn't happen.

    What did happen? BMI chart says someone at 180 pounds measuring 5' 6.5" would be overweight by about 20 pounds. I cannot estimate your BFP without your waist measurement, though.
    I am curious how your case turned out.

    Well I don't know how much a DEXA scan would cost. I was still thinking of getting a bod pod done at 180. I'm 191 as of today. I might still do it just to see how much muscle mass I did lose. I will definitely post my results if I decide to in the forums. I hear too much that the bod pod is just as inaccurate as those scales.
    A university near me offered DEXA scans through the nutrition science department for $40. Cheaper than any bodpod I could find in my area.
  • yopeeps025
    yopeeps025 Posts: 8,680 Member
    senecarr wrote: »
    yopeeps025 wrote: »
    yopeeps025 wrote: »

    That I feel is a sad statistic too. My original goal was to try to be 180 lb with 15% body fat at height 5'6.5. That didn't happen.

    What did happen? BMI chart says someone at 180 pounds measuring 5' 6.5" would be overweight by about 20 pounds. I cannot estimate your BFP without your waist measurement, though.
    I am curious how your case turned out.

    Well I don't know how much a DEXA scan would cost. I was still thinking of getting a bod pod done at 180. I'm 191 as of today. I might still do it just to see how much muscle mass I did lose. I will definitely post my results if I decide to in the forums. I hear too much that the bod pod is just as inaccurate as those scales.
    A university near me offered DEXA scans through the nutrition science department for $40. Cheaper than any bodpod I could find in my area.

    Yeah that is cheaper. Bod pod round my area cost 50. Maybe I should research more but I would still have to do both. Like you know use the same scale for trends.


    I tried through my doctor and they were like what is wrong. We usually only do DEXA for at risk people. That idea was trashed immediately.
  • jemhh
    jemhh Posts: 14,261 Member
    senecarr wrote: »
    yopeeps025 wrote: »
    yopeeps025 wrote: »

    That I feel is a sad statistic too. My original goal was to try to be 180 lb with 15% body fat at height 5'6.5. That didn't happen.

    What did happen? BMI chart says someone at 180 pounds measuring 5' 6.5" would be overweight by about 20 pounds. I cannot estimate your BFP without your waist measurement, though.
    I am curious how your case turned out.

    Well I don't know how much a DEXA scan would cost. I was still thinking of getting a bod pod done at 180. I'm 191 as of today. I might still do it just to see how much muscle mass I did lose. I will definitely post my results if I decide to in the forums. I hear too much that the bod pod is just as inaccurate as those scales.
    A university near me offered DEXA scans through the nutrition science department for $40. Cheaper than any bodpod I could find in my area.

    The university where I work charges the same for 1 and then you can get a 2 scan package for $70.
  • senecarr
    senecarr Posts: 5,377 Member
    jemhh wrote: »
    senecarr wrote: »
    yopeeps025 wrote: »
    yopeeps025 wrote: »

    That I feel is a sad statistic too. My original goal was to try to be 180 lb with 15% body fat at height 5'6.5. That didn't happen.

    What did happen? BMI chart says someone at 180 pounds measuring 5' 6.5" would be overweight by about 20 pounds. I cannot estimate your BFP without your waist measurement, though.
    I am curious how your case turned out.

    Well I don't know how much a DEXA scan would cost. I was still thinking of getting a bod pod done at 180. I'm 191 as of today. I might still do it just to see how much muscle mass I did lose. I will definitely post my results if I decide to in the forums. I hear too much that the bod pod is just as inaccurate as those scales.
    A university near me offered DEXA scans through the nutrition science department for $40. Cheaper than any bodpod I could find in my area.

    The university where I work charges the same for 1 and then you can get a 2 scan package for $70.
    The university I did it at had a student discount but I'm not a student. No two for one - they strictly limit it to six months between scans.

  • jemhh
    jemhh Posts: 14,261 Member
    senecarr wrote: »
    jemhh wrote: »
    senecarr wrote: »
    yopeeps025 wrote: »
    yopeeps025 wrote: »

    That I feel is a sad statistic too. My original goal was to try to be 180 lb with 15% body fat at height 5'6.5. That didn't happen.

    What did happen? BMI chart says someone at 180 pounds measuring 5' 6.5" would be overweight by about 20 pounds. I cannot estimate your BFP without your waist measurement, though.
    I am curious how your case turned out.

    Well I don't know how much a DEXA scan would cost. I was still thinking of getting a bod pod done at 180. I'm 191 as of today. I might still do it just to see how much muscle mass I did lose. I will definitely post my results if I decide to in the forums. I hear too much that the bod pod is just as inaccurate as those scales.
    A university near me offered DEXA scans through the nutrition science department for $40. Cheaper than any bodpod I could find in my area.

    The university where I work charges the same for 1 and then you can get a 2 scan package for $70.
    The university I did it at had a student discount but I'm not a student. No two for one - they strictly limit it to six months between scans.

    Do you know if there is a medical reason to limit it like that? I've looked at our website but the info about the scans is pretty sparse.
  • Packerjohn
    Packerjohn Posts: 4,855 Member
    999tigger wrote: »
    I just think the BMI is useless crowd embarass themselves, they spout it as though they have just made some major discovery but show their own ignorance when its understood its just a general population measure and doesnt claim to apply to everyone. We wll know it doesnt take into account muscle, but its for general populations for which its convenient.

    And the general population doesn't move doesn't lift weights etc so bmi is pretty reasonable for most people out there
  • senecarr
    senecarr Posts: 5,377 Member
    jemhh wrote: »
    senecarr wrote: »
    jemhh wrote: »
    senecarr wrote: »
    yopeeps025 wrote: »
    yopeeps025 wrote: »

    That I feel is a sad statistic too. My original goal was to try to be 180 lb with 15% body fat at height 5'6.5. That didn't happen.

    What did happen? BMI chart says someone at 180 pounds measuring 5' 6.5" would be overweight by about 20 pounds. I cannot estimate your BFP without your waist measurement, though.
    I am curious how your case turned out.

    Well I don't know how much a DEXA scan would cost. I was still thinking of getting a bod pod done at 180. I'm 191 as of today. I might still do it just to see how much muscle mass I did lose. I will definitely post my results if I decide to in the forums. I hear too much that the bod pod is just as inaccurate as those scales.
    A university near me offered DEXA scans through the nutrition science department for $40. Cheaper than any bodpod I could find in my area.

    The university where I work charges the same for 1 and then you can get a 2 scan package for $70.
    The university I did it at had a student discount but I'm not a student. No two for one - they strictly limit it to six months between scans.

    Do you know if there is a medical reason to limit it like that? I've looked at our website but the info about the scans is pretty sparse.
    The person doing it thought the university just wants to limit liability. The x-ray levels used in a DEXA scan are less than riding in a plane.
  • gdyment
    gdyment Posts: 299 Member
    senecarr wrote: »
    A university near me offered DEXA scans through the nutrition science department for $40. Cheaper than any bodpod I could find in my area.

    All the methods suck. Even getting a 2nd DEXA done a few hours after your first can have a variance of 5% in your total bodyfat - let alone on a different machine. Other than bragging rights, or if you do one every few months, it's not much use IMO. Photographs and tape measures for the most part.
  • senecarr
    senecarr Posts: 5,377 Member
    gdyment wrote: »
    senecarr wrote: »
    A university near me offered DEXA scans through the nutrition science department for $40. Cheaper than any bodpod I could find in my area.

    All the methods suck. Even getting a 2nd DEXA done a few hours after your first can have a variance of 5% in your total bodyfat - let alone on a different machine. Other than bragging rights, or if you do one every few months, it's not much use IMO. Photographs and tape measures for the most part.
    Tape measures can be just as unreliable.
    I don't have an aesthetic sense, so for me, $40 every once in a while is worth it to me.
    I never feel more data is a bad thing, just analysis can be bad.
  • MireyGal76
    MireyGal76 Posts: 7,334 Member
    edited July 2015
    But really... what is the point? I debated on paying money to get a scan to see what my BF % was. I wanted to know if I was <15%, or 16-18%...

    But the more I thought about it, the more I wondered why I NEEDED to spend the money. Would I be happier with my body if it said I was <15%? Would I be more content? When it comes down to it... the few % points DON'T mean *kitten* - unless you're competing.

    For someone like me who wants to look great and be fit... the mirror, the scale and tape measure are more than adequate to tell me if I'm fit or fat.

    Oh, and BMI tends to put me around 23% which is probably a fair bit high.
  • Fujiberry
    Fujiberry Posts: 400 Member
    Funny, I actually posted something about this on my facebook the other day! I linked a different article about people agreeing that BMI is useless.

    Here was my response:

    "Unpopular Opinion: The BMI chart is useless for athletes and also maybe for people who are somewhat fit, but I think the BMI is still a pretty good guideline for the majority of people.

    [CHART: http://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmi_tbl.htm]

    >25 BMI is considered overweight
    >30 BMI IS considered obese

    I'm 5'2" (62 inches), and I would be considered overweight starting at 142 lbs, and obese starting at 169 lbs.

    169 lbs on my 5'2" frame is definitely overweight and even if I was very active and was an experienced bodybuilder, I would be ENORMOUS at 169."
  • senecarr
    senecarr Posts: 5,377 Member
    MireyGal76 wrote: »
    But really... what is the point? I debated on paying money to get a scan to see what my BF % was. I wanted to know if I was <15%, or 16-18%...

    But the more I thought about it, the more I wondered why I NEEDED to spend the money. Would I be happier with my body if it said I was <15%? Would I be more content? When it comes down to it... the few % points DON'T mean *kitten* - unless you're competing.

    For someone like me who wants to look great and be fit... the mirror, the scale and tape measure are more than adequate to tell me if I'm fit or fat.

    Oh, and BMI tends to put me around 23% which is probably a fair bit high.

    For most people, I'd agree. In fact, I actually did a tape measure based estimate a few weeks earlier that had just 2 lbs less lean body mass. For me, I'm analytical and always intrigued in learning enough that I viewed doing the DEXA as something to reward the weight I'd lost so far. I actually did it around Father's Day and told my boys it was their gift to me.

    BMI doesn't predict body fat percentage - it is expressed as kg/m^2. The idea behind it is if people get above 25 and they aren't athletic, they're probably overweight. Being tall can also skew it a bit.
  • shifterbrainz
    shifterbrainz Posts: 245 Member
    Undeniably Much Ado About Nothing :smirk:
  • Go_Mizzou99
    Go_Mizzou99 Posts: 2,628 Member
    BMI was a goal when I was 75 pounds heavier. When I made goal (175 pounds - 23.7 BMI) it was no longer important. I lifted, could bang out chin ups from a dead hang, rode miles and miles of trails on my bike, etc. I was in the best shape of my life.

    Now - due to a couple of injuries and related surgeries/recoveries and the associated limited activities/10-lbs. weight restrictions, my weight has not changed but I now have a gut, I am freakin' soft...still pretty close to the same pre-injury BMI (now a 24.4 - 5 pounds heavier)... but I feel like I am supersizing all over again.

    Next Wednesday - all restrictions are lifted! Can't wait!!! Easing back into shape soon.
  • mumblemagic
    mumblemagic Posts: 1,090 Member
    edited July 2015
    Mayor_West wrote: »
    TR0berts wrote: »
    Um, nope. You only need height and weight.

    See? Even easier than you thought!

    True, but they slot you in to the limited categories based on age and gender.

    Nope, in the uk they slot you in arbitrary categories regardless of age, gender, ethnic background.


    ETA:
    They shouldn't, but BMI is still a useful indicator, even if it is horribly crude.

    http://michigantoday.umich.edu/a8500/
  • foursirius
    foursirius Posts: 321 Member
    Works quite well as a starting point. Of course there are exceptions like with most things, but it does a good job for the masses.
  • MireyGal76
    MireyGal76 Posts: 7,334 Member
    senecarr wrote: »
    MireyGal76 wrote: »
    But really... what is the point? I debated on paying money to get a scan to see what my BF % was. I wanted to know if I was <15%, or 16-18%...

    But the more I thought about it, the more I wondered why I NEEDED to spend the money. Would I be happier with my body if it said I was <15%? Would I be more content? When it comes down to it... the few % points DON'T mean *kitten* - unless you're competing.

    For someone like me who wants to look great and be fit... the mirror, the scale and tape measure are more than adequate to tell me if I'm fit or fat.

    Oh, and BMI tends to put me around 23% which is probably a fair bit high.

    For most people, I'd agree. In fact, I actually did a tape measure based estimate a few weeks earlier that had just 2 lbs less lean body mass. For me, I'm analytical and always intrigued in learning enough that I viewed doing the DEXA as something to reward the weight I'd lost so far. I actually did it around Father's Day and told my boys it was their gift to me.

    BMI doesn't predict body fat percentage - it is expressed as kg/m^2. The idea behind it is if people get above 25 and they aren't athletic, they're probably overweight. Being tall can also skew it a bit.

    Yes, and I'm a tall female (6'1") with a decent muscle base.
This discussion has been closed.