stupid BMI scale...

[Maggie May]

Okay, this question is not about me, it's about my husband.

While we both realize the BMI scale is flawed (doesn't account for body type/muscle mass etc), last night he was complaining that he is now into the "overweight category."

Background: He was overweight his whole life. In college he lost about 100 lbs and has kept it off for about 6 years now. He had terrible asthma growing up, and has now stopped using medication. I never knew him when he was overweight; we met in a kickboxing class. Since I've known him he's always been very health-conscious and put a priority on eating right and working out. He's run 3 marathons in amazing times... and recently started doing CrossFit with me. He never did any strength training before besides the occasional pushups/squat/"chest press machine."

Okay so. He had a doctor appointment yesterday and the doc pointed out that he's been "gaining weight" over the past couple checkups. (he has gained 15-20 lbs since the summer maybe?) Some family & friends have commented on how he's "bulked up" recently - in a good way. I've noticed his increasing muscle and think he looks great. (personally I think he gets too skinny when he trains for marathons... but... I digress..)

Last night after his dr. appt. he was all concerned that he is now in the overweight category on the BMI scale. (he also had slightly high blood pressure...which is what I think sparked his concern.) He's 5'10" and 180lbs. According to our bathroom scale (also probably slightly flawed) he's about 19% body fat, but I don't know where it is... he looks pretty lean to me!

I don't really know what my question is... how would you help him? I don't know what to tell him; he really wants to lose fat & not muscle, but won't give up his "carbs" because he "needs" them for running. Fine. I'm not arguing with him on that... but I don't know what else to suggest. I know he kind of has a stigma because he used to be overweight for so long... but I don't want him thinking he's "fat" when he's definitely not. Thoughts??

(sorry for the long post.)

[Gainsdalf the Whey]

I'm 6' 1/2", 245 lb, 25% body fat and apparently category 1 obese according to BMI. With my current lean body mass, I would have to be 3% body fat to be on the upper bounds of normal.

Know who else is class 1 obese with a BMI of 33? Ray Lewis is 6'1" and 250lb. Does this man look obese to you?

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Troy Polamalu is 5'10" 207 lb, which is just under class 1 obese. Whatcha think?

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BMI is calculated straight from height and weight. I know 6'0" dudes that are 170 lb (BMI23, normal) and in amazing shape and 6'0" dudes that are 250lb (34 BMI, almost class 2 obese) and in amazing shape. It doesn't take into account body comp at all and is therefor VERY flawed.

[m00se]

I would tell him to chill. I'm well inside the overweight category, and I have very close to 10% body fat these days. I was also in it when I was about 25% body fat, which should give you some idea about its usefulness (although I was further inside the band on the chart back then!)

BMI is a useful tool to stratify large chunks of the population into vague (and very wide) bands, and certainly from a surgical viewpoint I can tell you that we only really worry about people with very high BMIs (35+), usually because it precludes them from surgery (I assume it translates to other branches of medicine, but I'm a surgeon so I can only speak about what I know).

I can also tell you that when someone is referred to me for consideration of surgery, and they have a BMI of 40, I can be pretty fracking sure they're really, really fat. If someone comes to me with a BMI of anything from 15-25, I have precisely no idea what they look like or whether they're likely to be fit for an operation, because that band encompasses everything from lean, wiry athletic types to people with a fair bit of fat (and either of those could be at either end of the scale). In short, I just can't be sure what they look like and what their general health is likely to be like.

Also - crucially - it doesn't matter what your BMI is. A BMI is just a number, and it means precisely nothing when it's taken in the context of your overall general health; unless, of course, you're 35+, at which point you're just plain fat, however way you slice it (unless you're an outstanding bodybuilding specimen, but they are very, very few and far between).

[Waldo]

For men waist:height ratio is a significantly better measure than BMI.

(look at Corey's photos, neither of those guys would be considered overweight by waist:height ratio)

[Maggie May]

Thanks for your responses, guys. We realize the BMI scale is totally flawed... I think he just freaked out. Corey, I texted him those pics... I think it made him feel better

[Gainsdalf the Whey]

Thanks for your responses, guys. We realize the BMI scale is totally flawed... I think he just freaked out. Corey, I texted him those pics... I think it made him feel better

It's how I always justify it to myself. I go look at the 225 pounders at my height that I want to be similar to, realize the BMI scale is a moron when it comes to them, and move on. I figured it would help him to.

[Corbab]

The BMI scale was calculated from an extremely limited range of test data in a time when the peak of physical fitness was a strong chin, a stout pot belly, and a fine mustache. It's useful as a basic metric for health on the extreme ends of the scale, but it isn't taken seriously by anyone worth their salt in the health profession (even most doctors will cop to it being bogus).

This is a pretty solid debunking of BMI.

[Anivair]

Here's the trick. BMI works *okay* if you're not very muscular and if you do not have very dense muscle/bones. It's really just height versus weight. If your husband is built like the average man without a ton of muscle, then BMI will work. if he's got good tone and some lifting bulk, then it's not handy. the only thing it's good for is telling you what you weight relative to how tall you are.

For most people, it's actually not a bad indicator, though. Everyone hates on it because they want to think that they are an exception and maybe some of them are. Most people are average, though (hence the word).

Not the best tool. I use it for people that want to lean down without building a lot of muscle, because it's a thing they can see change, but TBH, I'd rather see a consistent BFP measurement or just photos. If he looks good (or better) naked, then BMI is irrelevant.

[This is Seth]

For men waist:height ratio is a significantly better measure than BMI.

I've never seen waist:height ratio used before. Does anyone who actually knows their bf% mind plugging in their numbers at this link to see how far off this is? I put in my numbers and there is no way that I'm at the bf% they have for me.

[Gainsdalf the Whey]

Mine is accurate when I make sure I put in my waist size at 1" above my belly button, which is much larger than that where I wear my pants.

[Waldo]

Mine is accurate when I make sure I put in my waist size at 1" above my belly button, which is much larger than that where I wear my pants.

I don't actually know mine, but I use that formula plus the Navy one and track them both.

I've actually flipped, it used to be my pants measure was smaller than 1" above my belly button, but now it is the other way around. Right around a W:H of 53% (about where the health risks associated with being overweight increase) is where the flip occurred for me. Somewhere in that area is also where I stopped viewing myself as fat psychologically.

I think the Willouhgby ideal athlete measurements are pretty good numbers to shoot for physically as a general fitness target (you can look up the full gamut for your height, there is a measurement for every major muscle group and joint), they are about a pro WR or DB body (204 lb @ 6'1" for me). I bet both Troy and Ray have a W:H pretty close to 45.8%.

[Zorch]

I've never seen waist:height ratio used before. Does anyone who actually knows their bf% mind plugging in their numbers at this link to see how far off this is? I put in my numbers and there is no way that I'm at the bf% they have for me.

I'd guess the numbers from that formula are *slightly* low for me, but not grossly off. More accurate than the electronic fat-measuring device at my gym that tried to tell me I was at <5% BF when I was probably closer to 12%.

And to the original topic, body fat percentage is a much better metric than BMI. For a man, a body fat level in the teens is pretty normal, less than 10% is really lean. I wouldn't sweat things too much in your husband's case.

[aj_rock]

Waist:hip ratio is another popular one. Very good for discerning risks for diabetes, HBP, CHD/CAD, etc.

[This is Seth]

Mine is accurate when I make sure I put in my waist size at 1" above my belly button, which is much larger than that where I wear my pants.

That measurement looks more like what I'd expect for bf%, though I'm in the increased risk for males for WHtR now.

Sorry, no more thread-jacking. :/

[Anivair]

http://www.bmi-calculator.net/waist-to-hip-ratio-calculator/

I use that for waist/hip (and BFP most of the time). I like the site. No, BMI isn't great, but the rest of the tools there are good.

[Waldo]

That measurement looks more like what I'd expect for bf%, though I'm in the increased risk for males for WHtR now.

Sorry, no more thread-jacking. :/

One thing to know about that calculator, it uses its own formula.

Men BF% = 100*(-98.42 + 4.15*waist - 0.082*weight)/weight

This is very close to another readily available formula, the only difference being the 98.42 is changed to 94.42. I can't imagine they made such a critical typo (both in writing down the formula and the actual calculator), so there has to be reasoning behind it.

I've always thought that between the two tape measure BF% formulas, they make a good bounding box of range. The Navy formula seems to give a really high number for LBW/low number for BF%, and vice versa this formula with a 94.42 instead of 98.42 seems to give a really low number for LBW/high for BF%. Overall I use an average of the two. Using 98.42 is closer to the average between the two. For it to be perfectly average for me between the two formulas you'd have to use about 99.92 (they aren't perfectly parallel over various waist measures for me, but very, very close to it).

[JoeBlade]

Don't forget that BMI was never intended for individuals. "BMI was explicitly cited by Keys as being appropriate for population studies, and inappropriate for individual diagnosis." It's only useful to gauge the overall 'heavyness' of populations. in a large enough group, the fit and the unfit tend to balance eachother out a bit, and you get a decent inidication of how heavy joe-average is. For a large population, a high BMI is a good indication that that population is getting obese.

anyways... I'm still happy to register in 'normal' finally after half a year. But it doesn't really mean anything

[notanartmajor]

BMI can die in a hole. If he looks good and feels good, then chances are he is good, at least as far as weight-related issues are concerned. However, if he does have high blood pressure and that wasn't a fluke, it would pay to keep an eye on that.