plansrme Posted February 17, 2015 Share Posted February 17, 2015 We have discussed before how BMI calculators are not terribly reliable, so I am posting our experience in case anyone else is disturbed by their use especially when it comes to their athletic kiddos. According to the BMI calculator, my 15 yo swimmer daughter's BMI is 24.9, and 25 or above is considered overweight. She swims nine times a week, and is short but ridiculously muscular. Think "Shawn Johnson" in her competition days. Anyway, she volunteered to be part of a college student's project, and as part of the study, she had a body fat composition test in a machine that is supposed to be as accurate as (but less messy than) a dunk tank test. My "nearly-overweight" daughter has 14.4% body fat. That is below the "ultra-lean elite athlete" level (15-18%) according to the chart they gave us. The chart actually puts her in the "danger zone." If you saw her in a swimsuit, you would never think she looks like a skinny-minnie, but she actually may need to add some doughnuts to her diet. As far as I can tell, she likes her muscles and is happy with her size (except that she would love to be taller--she is short for a swimmer). Lord knows if I looked like her, I would walk around naked all the time. But I digress. The point of all this is that I know she is not overweight, not even close, and I am thrilled that we have proof. Quote Link to comment Share on other sites More sharing options...
Tsuga Posted February 17, 2015 Share Posted February 17, 2015 BMI is one of the worst tools for measuring health in brute terms. I've seen it applied to babies. Nuts. I am glad your daughter got some validation to back up her self-knowledge. Quote Link to comment Share on other sites More sharing options...
clementine Posted February 17, 2015 Share Posted February 17, 2015 I hate the BMI calculations - especially for athletes. I believe it creates a possible trigger for eating disorders. I also have an athlete and she certainly doesn't look like she weighs what she does, but she is all muscle. I would hate for her to have the idea put into her head that she is borderline overweight....ridiculous and sad! Quote Link to comment Share on other sites More sharing options...
kiana Posted February 17, 2015 Share Posted February 17, 2015 Totally. BMI was intended for population-level studies, not for individuals. Applying BMI to a clearly-lean individual is ridiculous. Here are a couple of interesting websites with visual estimates of bodyfat %. http://www.builtlean.com/2012/09/24/body-fat-percentage-men-women/ http://www.ruled.me/visually-estimate-body-fat-percentage/ warning: shirtless pics for men, bikini for women Quote Link to comment Share on other sites More sharing options...
The Girls' Mom Posted February 17, 2015 Share Posted February 17, 2015 BMI charts are often a bad idea, IMO. In order to get below the overweight range, I would look absolutely malnourished. At *my* healthiest weight, I'm firmly in the overweight range. Right now, I'm in the obese range and would really only consider myself overweight. I'm losing and my goal is to get back to a mid-range that I'm comfortable with. Right now I can wear non-plus size clothes, etc. However, I'm a big girl. Tall, broad shoulders, large frame, etc. I would have to lose 80 more pounds to get into "normal" range and would have to starve myself to get there! Quote Link to comment Share on other sites More sharing options...
The Girls' Mom Posted February 17, 2015 Share Posted February 17, 2015 Totally. BMI was intended for population-level studies, not for individuals. Applying BMI to a clearly-lean individual is ridiculous. Here are a couple of interesting websites with visual estimates of bodyfat %. http://www.builtlean.com/2012/09/24/body-fat-percentage-men-women/ http://www.ruled.me/visually-estimate-body-fat-percentage/ warning: shirtless pics for men, bikini for women That is helpful! I am around 35-40% according to that...much more in line with what I know about my body than the BMI charts. Quote Link to comment Share on other sites More sharing options...
hornblower Posted February 17, 2015 Share Posted February 17, 2015 IMHO,BMI charts WORK for everyone except elite athletes and pregnant women (& sometimes fast growing teens) If you're an elite athlete, carry on, do your stuff & don't pay attn to bmi charts (until you stop training. Then start paying attn because all that muscle turns into fat fast..)If you're not an elite athlete, listen to the BMI chart. If you really want more data to convince you, get caliper tested for body fat %. It's also not 100% accurate because it does depend a bit on the skill of the person wielding calipers (but it's cheaper than getting dipped for body fat) but again, if combined with bmi it indicates you're over, you're over. Of course there's a variation in build - that's why the bmi ranges are actually quite wide. I can go up and down <20 lbs & still be within normal bmi range. Quote Link to comment Share on other sites More sharing options...
umsami Posted February 17, 2015 Share Posted February 17, 2015 IMHO, BMI charts WORK for everyone except elite athletes and pregnant women (& sometimes fast growing teens) If you're an elite athlete, carry on, do your stuff & don't pay attn to bmi charts (until you stop training. Then start paying attn because all that muscle turns into fat fast..) If you're not an elite athlete, listen to the BMI chart. If you really want more data to convince you, get caliper tested for body fat %. It's also not 100% accurate because it does depend a bit on the skill of the person wielding calipers (but it's cheaper than getting dipped for body fat) but again, if combined with bmi it indicates you're over, you're over. Of course there's a variation in build - that's why the bmi ranges are actually quite wide. I can go up and down <20 lbs & still be within normal bmi range. Might just be a common phrase, but muscle can't turn into fat. Ever. Impossible. Different cells. Losing muscle mass decreases one's basal metabolic rate, but that's about it. (The rise/decrease is not significant...around 5-6 kcal/pound/day). BodPods are more effective than calipers and not reliant on the skill. No dipping, and many gyms and University athletic centers offer it. Quote Link to comment Share on other sites More sharing options...
plansrme Posted February 17, 2015 Author Share Posted February 17, 2015 Might just be a common phrase, but muscle can't turn into fat. Ever. Impossible. Different cells. Losing muscle mass decreases one's basal metabolic rate, but that's about it. (The rise/decrease is not significant...around 5-6 kcal/pound/day). BodPods are more effective than calipers and not reliant on the skill. No dipping, and many gyms and University athletic centers offer it. The BodPod is what my daughter's test was in. Quote Link to comment Share on other sites More sharing options...
SKL Posted February 17, 2015 Share Posted February 17, 2015 Right. My eldest tests above average for BMI (I haven't tested it lately, but she's only gotten more muscular). She still wears size 2-3 toddler underwear (she is 8yo and wears size 7 clothes for the length.) I don't check her weight or BMI (nor that of my other kid, who is less athletic but still active). I look at their slim waists and dare anyone to say a word to me about fat. And my kid is not an "elite athlete." She does recreational activities 7-10 times per week, plus school gym and recess and general messing around. Quote Link to comment Share on other sites More sharing options...
kiana Posted February 17, 2015 Share Posted February 17, 2015 IMHO, BMI charts WORK for everyone except elite athletes and pregnant women (& sometimes fast growing teens) If you're an elite athlete, carry on, do your stuff & don't pay attn to bmi charts (until you stop training. Then start paying attn because all that muscle turns into fat fast..) If you're not an elite athlete, listen to the BMI chart. If you really want more data to convince you, get caliper tested for body fat %. It's also not 100% accurate because it does depend a bit on the skill of the person wielding calipers (but it's cheaper than getting dipped for body fat) but again, if combined with bmi it indicates you're over, you're over. Of course there's a variation in build - that's why the bmi ranges are actually quite wide. I can go up and down <20 lbs & still be within normal bmi range. The BMI chart doesn't even really work there. There are also quite a few people (especially older women) where BMI tells them that they are in a healthy weight range and they really are overweight. I would recommend that most people get a caliper test (which is quite cheap) or get a trusted and honest friend to use some of the visual estimator comparisons (less accurate but free) or even a tape test (ditto). Quote Link to comment Share on other sites More sharing options...
Katy Posted February 17, 2015 Share Posted February 17, 2015 It's so easy to assess someone's bodyfat with calipers or one of those electrical resistance machines. Why do we bother with BMI at all? Quote Link to comment Share on other sites More sharing options...
Tsuga Posted February 17, 2015 Share Posted February 17, 2015 You can do BMI without looking at the person. It was developed primarily for working with large datasets without getting new information. Lazy statistics. Quote Link to comment Share on other sites More sharing options...
hornblower Posted February 17, 2015 Share Posted February 17, 2015 sorry, yes, it was just a turn of phrase. I was alluding to the jocks I know who turned into fat. Some of them still think they're 'just big guys' but they're just plain fat. They're eating the same as they used to when they were 20 & running after a ball for hours. Now they're lucky to play a couple hours a week, their metabolism has slowed & they've put on a lot of fat. Those pecs now are flabby fat covering some shrivelled muscle & let's not talk about the beer pouchy bellies... So it's not that muscle turns into fat literally. It's that muscle atrophied and the fat grew. I find bmi extremely hard to judge with the eye. My dh is smack in the middle of the bmi charts but he's very tall and slender and people constantly tell him to gain weight. I'm at the lower 1/3 of my healthy bmi & still carry a muffin top. I don't think anyone looking at us side by side would guess that I had lower bmi than he but maybe binip you're better at this than I am LOL. And when I was at the top of my bmi, kissing the overweight line, I don't think I looked overweight. I've looked at the photos & I still don't think I looked close to being overweight.. I'm not good at this stuff so I need the scale & the charts :) Quote Link to comment Share on other sites More sharing options...
chocolatechip Posted February 17, 2015 Share Posted February 17, 2015 I find it very telling to compare weight ranges for certain heights in relatively new diet books and those that are older. Newer books always allow a higher weight for the SAME height and build levels.... Sometimes I wonder if we are just trying to make ourselves feel good. Quote Link to comment Share on other sites More sharing options...
hornblower Posted February 17, 2015 Share Posted February 17, 2015 I find it very telling to compare weight ranges for certain heights in relatively new diet books and those that are older. Newer books always allow a higher weight for the SAME height and build levels.... Sometimes I wonder if we are just trying to make ourselves feel good. I definitely think that's so. Similar thing happened with the physical exercise targets. Nobody was meeting them so they dropped the targets, just so we could now say more people are exercising! Um, no. They're not. Quote Link to comment Share on other sites More sharing options...
kiana Posted February 17, 2015 Share Posted February 17, 2015 I definitely think that's so. Similar thing happened with the physical exercise targets. Nobody was meeting them so they dropped the targets, just so we could now say more people are exercising! Um, no. They're not. Well, I actually think (with the exercise) that it's more of a "if we set a goal that's more attainable, people will be more likely to hit it -- and any exercise is better than none". Similarly to how it was calculated that it would be better to do 7 servings of fruit + veg a day, but it was set at 5 because that was where more people would respond to the goal. Quote Link to comment Share on other sites More sharing options...
hornblower Posted February 17, 2015 Share Posted February 17, 2015 I know but where does it end? French fries are vegetables! Walking from living room to bathroom is aerobic exercise! jk. Sort of. Quote Link to comment Share on other sites More sharing options...
Kim in Appalachia Posted February 17, 2015 Share Posted February 17, 2015 We had a girl on our swim team end up with an eating disorder for almost two years, because some idiot at school told her that her BMI put her at obese. The girl was about 5'5" and all muscle. She worked out 3 hrs a day, doing weights in the morning and swimming in the afternoon, plus running on the weekends. She had a shorter torso (which I think affects the BMI). That poor girl. She became obsessed with every bite she took. Her eating problems effected her swimming. She wasn't eating enough and she could no longer make her times. Thankfully, by college, she realized that she was fine how she was, and starting eating correctly again. It was so hard to watch her go through that. My sister also had problems with her infant son. His height was at 5% and weight closer to 30% so the nurse kept telling her the baby was "obese" (He was less than a year old!). Thankfully, the doctor knew it was stupid and get reassurring her that her son was fine. Quote Link to comment Share on other sites More sharing options...
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