# What's your BMI poll **URL:** \ **Category:** In My Humble Opinion\ **Created:** [October 26, 2011, 3:15pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860 "2011-10-26T15:15:24Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Acid\_Lamp](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@Acid\_Lamp](https://boards.straightdope.com/u/Acid_Lamp)\ **Post date:** [October 27, 2011, 12:33pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/41 "2011-10-27T12:33:55Z")
[Judge for yourself](http://www.flickr.com/photos/24805009@N03/6203988106/). I just got done with a weight gain/ muscle building program. At my current weight, I’m just on the side of “overweight”. True, I don’t have the super cut look and minimal body fat of an endurance athlete but I’m hardly fat either. ---
**Author:** ![not\_what\_you\_d\_expect](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/not_what_you_d_expect/32/3246_2.png) [@not\_what\_you\_d\_expect](https://boards.straightdope.com/u/not_what_you_d_expect)\ **Post date:** [October 27, 2011, 12:38pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/42 "2011-10-27T12:38:36Z")
Nicely fit there, Acid Lamp. Good job. I’m 5.1 and 120lbs right now. That puts my BMI at 22.7 per the chart provided in the op. So, I’m normal…at least with regards to my weight. 🙂 ---
**Author:** ![jjimm](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@jjimm](https://boards.straightdope.com/u/jjimm)\ **Post date:** [October 27, 2011, 1:18pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/43 "2011-10-27T13:18:06Z")
> [@Broomstick](#): > > A good BMI calculator will ask for sex A _sleazy_ BMI calculator… ---
**Author:** ![even\_sven](https://avatars.discourse-cdn.com/v4/letter/e/dfb087/32.png) [@even\_sven](https://boards.straightdope.com/u/even_sven)\ **Post date:** [October 27, 2011, 1:25pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/44 "2011-10-27T13:25:12Z")
I like [this diagram](http://www.mach-1.de/staffs_2_1.html) as a supplement to BMI. It shows drawings of an approximate body form for different levels fo BMI. ---
**Author:** ![Mr.Skinny](https://avatars.discourse-cdn.com/v4/letter/m/3be4f8/32.png) [@Mr.Skinny](https://boards.straightdope.com/u/Mr.Skinny)\ **Post date:** [October 27, 2011, 2:00pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/45 "2011-10-27T14:00:17Z")
6’0"/135 bmi 18.3 ---
**Author:** ![Antigen](https://avatars.discourse-cdn.com/v4/letter/a/848f3c/32.png) [@Antigen](https://boards.straightdope.com/u/Antigen)\ **Post date:** [October 27, 2011, 2:18pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/46 "2011-10-27T14:18:15Z")
Just recently tipped over the 25.0 mark and I’m officially overweight. I’m a little bummed about it. Even my Wii Fit seems disappointed in me when she weighs me and sighs “that’s overweight”. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [October 27, 2011, 3:10pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/47 "2011-10-27T15:10:36Z")
> [@jjimm](#): > > A _sleazy_ BMI calculator… 🙂 Actually I have never heard of gender modification of the definitions of “overweight” and “obese” by BMI. Using _body fat percentage_ to define obesity, yes, but “normal” females have both more fat and less muscle than “normal” males, which offset each other in the BMI norms. See [here](http://emedicine.medscape.com/article/123702-overview). > [@](#): > > Obesity represents a state of excess storage of body fat. Although similar, the term overweight is puristically defined as an excess body weight for height. Although men have a body fat percentage of 15-20%, women have approximately 25-30%.[1] Because differences in weight among individuals are only partly due to variations in body fat, body weight is a limited, though easily obtained, index of obesity. > > The body mass index (BMI), also known as the Quetelet index, is used far more commonly than body fat percentage to define obesity. BMI is closely correlated with the degree of body fat in most settings. … > > … Although the BMI is typically closely correlated with percentage body fat in a curvilinear fashion, some important caveats to its interpretation apply. In mesomorphic (muscular) persons, BMIs that usually indicate overweight or mild obesity may be spurious, whereas in some persons with sarcopenia (especially among persons of Asian descent), a typically normal BMI may conceal underlying excess adiposity characterized by increased percentage fat mass and reduced muscle mass. > > In view of these limitations, some authorities advocate a definition of obesity based on percentage body fat. For men, percentage body fat greater than 25% defines obesity, and 21-25% is borderline. For women, over 33% defines obesity, and 31-33% is borderline. … > > … Other indices used to estimate the degree and distribution of obesity include the 4 standard skin thicknesses (ie, subscapular, triceps, biceps, suprailiac) and various anthropometric measures, of which waist and hip circumferences are the most important. > > Although several classifications and definitions for degrees of obesity are accepted, the most widely accepted is the World Health Organization (WHO) criteria based on BMI. Under this convention for adults, grade 1 overweight (commonly and simply called overweight) is a BMI of 25-29.9 kg/m2. Grade 2 overweight (commonly called obesity) is a BMI of 30-39.9 kg/m2. Grade 3 overweight (commonly called severe or morbid obesity) is a BMI greater than or equal to 40 kg/m2. ---
**Author:** ![elfkin477](https://avatars.discourse-cdn.com/v4/letter/e/a9a28c/32.png) [@elfkin477](https://boards.straightdope.com/u/elfkin477)\ **Post date:** [October 27, 2011, 8:12pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/48 "2011-10-27T20:12:31Z")
> [@Broomstick](#): > > I have. Although my BMI is slightly into the overweight range my body fat is actually slightly less than expected for someone my gender and weight. Just for funsies, would you compare what [this caluculator](http://home.fuse.net/clymer/bmi/) comes up with to the real test you took? You’ll need a measuring tape for the waist measurement, fyi. I suspect that the calulator will claim a lower bodyfat % than your real test did, because it’s hard to square that BMI wants me to lose 8 or more pounds while the calulator estimates I have 17% bodyfat. ---
**Author:** ![rhubarbarin](https://avatars.discourse-cdn.com/v4/letter/r/eb9ed0/32.png) [@rhubarbarin](https://boards.straightdope.com/u/rhubarbarin)\ **Post date:** [October 27, 2011, 9:19pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/49 "2011-10-27T21:19:58Z")
[This body fat % calculator](http://fitness.bizcalcs.com/Calculator.asp?Calc=Body-Fat-Navy) has been found to be very accurate by people who have also had their body fat tested by the most exact methods, such as a DEXA scan or professionally administered calipers on 7 points (I belong to several online communities focused on weight lifting, paleo diet, etc where people care enough to get their body fat formally measured). **elfkin’s** calculator tells me I have 9% body fat, haha. The Navy calculator tells me 17%, which is only a couple percentage points below the last DEXA I had. ---
**Author:** ![MeanOldLady](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/meanoldlady/32/10737_2.png) [@MeanOldLady](https://boards.straightdope.com/u/MeanOldLady)\ **Post date:** [October 27, 2011, 9:51pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/50 "2011-10-27T21:51:19Z")
Oh snap! I voted too soon. I’ve been at the high end of the healthy range for a long time, and I ran off to the BMI calculator just now just for shits and giggles, only to discover that my BMI is now 25.1. I am officially overweight. \ Edit: LOL. The calculator above said I’m obese. That is hilarious! ---
**Author:** ![chiroptera](https://avatars.discourse-cdn.com/v4/letter/c/df705f/32.png) [@chiroptera](https://boards.straightdope.com/u/chiroptera)\ **Post date:** [October 27, 2011, 10:24pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/51 "2011-10-27T22:24:01Z")
Elfkin’s calculator has me at 21.9% fat, 22.8 BMI, right at the bottom end of the range for my age group. The Navy calculator says I’m “acceptable” with 25% body fat, wow that seems like a lot. Body Fat 25 % Fat Mass 36 lbs Lean Mass 109 lbs Body Fat Category Acceptable ---
**Author:** ![Acid\_Lamp](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@Acid\_Lamp](https://boards.straightdope.com/u/Acid_Lamp)\ **Post date:** [October 28, 2011, 1:38am UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/52 "2011-10-28T01:38:04Z")
> [@rhubarbarin](#): > > [This body fat % calculator](http://fitness.bizcalcs.com/Calculator.asp?Calc=Body-Fat-Navy) has been found to be very accurate by people who have also had their body fat tested by the most exact methods, such as a DEXA scan or professionally administered calipers on 7 points (I belong to several online communities focused on weight lifting, paleo diet, etc where people care enough to get their body fat formally measured). > > **elfkin’s** calculator tells me I have 9% body fat, haha. The Navy calculator tells me 17%, which is only a couple percentage points below the last DEXA I had. Interesting. It returned 15 % for me, and rated me fit. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [October 28, 2011, 7:58am UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/53 "2011-10-28T07:58:20Z")
Now see for the Navy body fat % calculator gender really matters. **chiroptera** , your female gender has a “normal” body fat percent range of 25-30%, so your 21 to 25% is a lean female indeed. I come (male 52 years old) out as 19% on the Navy one and 16.5% with a BMI of 25.2 on the one **elfkin** links too. Male body fat percent normal according to my link is 15 to 20%, so while I am pleased that I am considered in the acceptable range, I aint lean. You are much leaner than I even though you have a higher body fat percent. My waist to height is also just on the edge of healthy at 50%. Oh, another tool is the [waist to hip ratio](http://www.bmi-calculator.net/waist-to-hip-ratio-calculator/). That one puts me at 0.94, low health risk. Fun toys. ---
**Author:** ![Cazzle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cazzle/32/75_2.png) [@Cazzle](https://boards.straightdope.com/u/Cazzle)\ **Post date:** [October 28, 2011, 8:22am UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/54 "2011-10-28T08:22:20Z")
1. I’m heading down the chart, finally out of Obeseville and chugging through Overweight State. Healthy range, look out! Here I come! ---
**Author:** ![jjimm](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@jjimm](https://boards.straightdope.com/u/jjimm)\ **Post date:** [October 28, 2011, 11:12pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/55 "2011-10-28T23:12:19Z")
Through regular exercise, stopping beer (boo hoo) and eating less over the course of a month I have dropped from 25.5 to 24, but more importantly my body fat has gone from 22% to 18%. I’m gonna keep going. ---
**Author:** ![MeanOldLady](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/meanoldlady/32/10737_2.png) [@MeanOldLady](https://boards.straightdope.com/u/MeanOldLady)\ **Post date:** [October 28, 2011, 11:53pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/56 "2011-10-28T23:53:12Z")
jim, doll, I thought you were taking a vacation your life and hibernating in a remote part of Malaysia somewhere for a year. Non? ---
**Author:** ![Sleel](https://avatars.discourse-cdn.com/v4/letter/s/73ab20/32.png) [@Sleel](https://boards.straightdope.com/u/Sleel)\ **Post date:** [October 29, 2011, 2:27am UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/57 "2011-10-29T02:27:41Z")
I’m currently at 23.7, with about 10% body fat. I dropped a couple of kg due to work interfering with my exercise schedule. When I was working out more regularly and lifting heavier, I was at about 24.4, with body fat about one percent lower. I’m in good, but not phenomenal shape. BMI is useful for giving a rough approximation of body classification, and should only be used to determine whether an _average sedentary_ person is statistically more likely to have certain health problems relative to other people in that cohort. The problem with BMI is that it has been misapplied and given greater significance than it deserves. Both Quetelet, who first came up with the original formula, and Keyes who revived and renamed the idea in the 1970s advised against using it to make diagnoses or give medical advice. They both realized it was a statistical tool, not a medical one. There’s a great article in Slate about the [history of BMI](http://www.slate.com/articles/health_and_science/science/2009/07/beyond_bmi.html) that I think everyone who has a question about the validity of BMI should read. There have been various kludges hacked onto it in the 150 years since it was first derived, as well as a few different formulas for determination. As an interesting, and possibly relevant aside, it was developed at about the same time as phrenology, which doesn’t really make me give much credence to it. The appeal is that it’s quick and easy to do with very minimal equipment. All you need is a tape measure and an accurate scale. Doctors like it for that reason and because it requires zero thought or interpretation. Waist-hip ratio is just as fast and easy to take a measurement for, but there aren’t hard cutoffs that allow you to say, “Okay then, according to the numbers you’re a fat bastard.” The problem is that it’s an unsophisticated blunt instrument. It’s kind of like navigating via dead-reckoning; pointing yourself in the right general direction and figuring out where the hell you are relative to your actual target after you hit a major nearby landmark to get your bearings. Knowing that you’re somewhere on the west coast of Britain might help you find London…eventually, but it’s not as useful as a sextant reading that lets you determine approximate latitude and longitude. So an “overweight” or “obese” reading _might_ help you objectively determine whether you’re fat or not, but it won’t do a damn thing to tell you about muscle mass, bone density, actual adiposity, at what sites your adipose tissue is deposited, etc. Most of the time, looking at an unclothed picture of yourself (doing this with the face covered helps you look at yourself more objectively) is about as accurate as BMI. If you look at the picture and think, “Woah, that dude is chunky,” congratulations, you’ve determined about as much useful information as BMI will tell you. The fastest, easiest, cheapest, and most relatively accurate way to get a determination of subcutaneous adiposity is probably by taking caliper measurements. It’s not as accurate as some of the more intensive methods, but it’s easier and cheaper than average density (water/air displacement volume measures correlated with weight) and worlds cheaper than a DXA scan. Even caliper measurements can be overgeneralized though. There are various formulae for overall body fat, but those should be used only with an “educated guess” level of confidence. The direct measurements can be quite accurate, but the calculations are based on statistical models, and typically have a couple of percentage points of slop, which can be exacerbated by measurement inaccuracies. If you really want to track your body composition, my suggestion would be to combine a few cheap and easy methods. You don’t need a very high level of accuracy unless you’re a pro athlete, and even then, performance measurements are much, much more useful than secondary indicators of fitness like body fat. [ol] [li]Mirror or camera.[/li][li]Scale weight. Track changes over time, minimize variables by weighing at the same time, in the same state. If you weigh in naked, after your dump, but before breakfast, on Sunday morning, do it that way every time. (Electric impedance scales are generally useless, sometimes even for tracking gross changes. Mine has never measured me at less than 20% body fat even though I lost 16 kg from when I first started using it, and gained very noticeable amounts of muscle. The number actually _went up_ at a few points in time while I was losing weight.)[/li][li]Skinfold caliper measurement. Most people only really need one site: suprailiac or abdominal. But the sweet spot of ease and accuracy is probably 3 sites. Men: pectoral, abdominal, and thigh. Women: triceps, suprailiac, and thigh. ExRx has an easy to read [guide to skinfold sites](http://www.exrx.net/Testing/BodyCompSites.html).[/li][li]If you feel like it, tape measurements of hip and waist. If you’re trying to get more muscular and want to track progress, arm, chest, neck, and thigh measures could be interesting too.[/ol][/li] Something you should never do is give any measurement undue authority. Body fat levels, no matter how accurate, do not give the whole picture. You need to take various indicators into account and not just rely on a single number to make a determination of health because any of those tests is not a direct measure of health; it’s a secondary indicator of one variable. ---
**Author:** ![Rand\_Rover](https://avatars.discourse-cdn.com/v4/letter/r/db5fbb/32.png) [@Rand\_Rover](https://boards.straightdope.com/u/Rand_Rover)\ **Post date:** [October 29, 2011, 3:55am UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/58 "2011-10-29T03:55:32Z")
> [@DSeid](#): > > 25.3. FWIW. > > It’s not perfect but it is not too awful either. Some past studies have shown the lowest mortality for those at the top of the normal and slightly into the “overweight” range, but [this very large study](http://www.nejm.org/doi/full/10.1056/NEJMoa1000367#t=articleTop), as summarized in [this figure](http://www.nejm.org/action/showImage?doi=10.1056%2FNEJMoa1000367&iid=f01) pretty well demonstrates that the lowest mortality rates are associated with BMIs of 22.5 to 24.9, and from 20.0 to 24.9 for healthy nonsmokers. Under 20 it goes up sharply and it goes up gradually as one goes over 25. (Interestingly per the figure the lowest for White male all is at about 26 (hazard ration of .97 compared to the 22.5 to 25.0 group) but White male healthy nonsmokers at 26 are starting the rise (1.06 compared to the same referent). So I guess I should drop about 4 pounds! Waitaminute–does this say that fat people are better off if they’ve smoked? ---
**Author:** ![Purple\_Scottie](https://avatars.discourse-cdn.com/v4/letter/p/a698b9/32.png) [@Purple\_Scottie](https://boards.straightdope.com/u/Purple_Scottie)\ **Post date:** [October 29, 2011, 1:51pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/59 "2011-10-29T13:51:45Z")
18.6 – 115 lbs at 5’6". It is the same as I weighed a year ago but after weight training 3x/week (in addition to the cardio I was already doing) I’m definitely more defined and _look_ better. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [October 29, 2011, 6:08pm UTC](https://boards.straightdope.com/t/whats-your-bmi-poll/600860/60 "2011-10-29T18:08:16Z")
> [@Rand\_Rover](#): > > Waitaminute–does this say that fat people are better off if they’ve smoked? No. Each curve is comparing to its own population normalized to 1.0 being at the lowest portion of the curve. Its intent is to show the different association of lower BMI with mortality in smokers vs non, for reasons that are not clear. [Previous page](https://boards.straightdope.com/t/whats-your-bmi-poll/600860.md?page=2)