Is the "Obesity Epidemic" a fantasy?

[brynndragon]

One of the things I noticed when examining the requirements for the study I'll be participating in is the BMI cutoff is 27. Which seems strange because the BMI cutoff for "overweight" is 25. Apparently it *was* 27 until 1998 when the National Heart, Lung, and Blood Institute (NHLBI) decided to make it 25. I can't for the life of me figure out why they made that decision. They state, "The rationale behind these definitions is based on epidemiological data that show increases in mortality with BMIs above 25 kg/m2." with several references. But only one of the references implies that lowering the cutoff might be beneficial (the one that states "available evidence suggests that minimum mortality occurs at relative weights at least 10% below the US average", where the average according to this article (referenced in other places in that NHLBI document) is right around BMI = 25 for women and somewhat above that for men - which makes me wonder why the hell they picked 25). All the rest use overweight = 27 as their basis for making statements about the link between overweight/obesity and morbidity, except the WHO report (PDF). The WHO report doesn't say a damn thing about links between obesity and morbidity/mortality (being focused on malnutrition), nor does it give any specific recommendations at all about where to set BMI even for determination of malnutrition (for which it has good reasons involving the risk of overlooking important aspects of the link between height/weight/age and morbidity/mortality, and translating it into useful intervention, which the NHBLI seems to have completely ignored).

The thing I really want to point out is almost all of the data they use to support the notion that being overweight leads to increased morbidity/mortality involves a BMI >27, not a BMI >25. This might explain why the study I'm participating in uses the 27 cutoff rather than the 25 cutoff.

I probably only care because my BMI is 26. Well, that and the idea that over half of Americans are overweight is based almost entire on this change for which I've found pretty much no freaking evidence. The more I learn, the more dubious I am of our notions of healthy weight. . .

Comments

[cos]

I'm pretty sure there's some of both.

On the one hand, yes, "obesity" is overestimated because we use bad numbers, and many people are considered overweight who shouldn't be.

On the other hand, yes, more Americans are overweight, and more are seriously overweight, than decades ago, and it is a problem.

The idea that you might be in the middle of that - not overweight, but mistakenly classified as such by some measures - makes sense.

[heinleinfan.livejournal.com]

Yeah, what he said.

[benndragon.livejournal.com]

I just don't think I'm overweight. I also don't think my mom or my aunt are overweight, but they obsess about losing weight (and seem disappointed that I haven't give them the mystical Chinese secret for being thin; I don't think they realize the mystical Chinese secret for being thin is malnutrition). Which makes me suspect the idea that we all need to lose weight has become the conclusion of things like the NHBLI guidelines (not that they said that, but that's what we as a society has decided such things mean) and that has had an overall detrimental affect on our health rather than a positive effect.

In conclusion, nutrition is hard, let's go shopping.

[bikergeek.livejournal.com]

My own personal ex recto theory for the change was that 1998 was about when the now-recalled diet drug Fen/Phen hit the market. Arbitrarily declaring millions of people "overweight" or "obese" with the stroke of a pen meant that many more prescriptions could be written.

Just like they keep lowering the bar for what's considered "high" cholesterol so they can keep writing more prescriptions for statins.

Medical "research" these days is driven almost entirely by drug companies seeking to pathologize the maximum number of people so as to maximize their income stream.

[benndragon.livejournal.com]

Actually, the culprit might be Big Agriculture rather than Big Pharma, if this Jim Lehrer NewsHour report is correct: "The U.S. Department of Agriculture promulgated the dietary guidelines for America in 1995, with a BMI healthy weight limit. The limit was at 25. The WHO, World Health Organization, uses that definition. All the countries around the world, all the European countries, Asian countries, India, Latin America, they use that definition, so we're not doing something radical or new or different. We're really coming into line with what was already federal guidelines and what the rest of the world uses to define overweight. "

[cos]

Not mutually exclusive. Pharmaceutical companies lobby the USDA a lot.

This is my burning ball of fury

[metahacker.livejournal.com]

1. BMI absolutely sucks as a diagnostic tool. It turns a cubed-relation into a squared-relation, is based on no experimental data, and ignores frame completely.

We might just as well say you should weigh 2 lbs per inch of height -- it literally makes as much sense, but because it doesn't have a square root in it it doesn't sound sciencey.

2. There is a rampant level of obesity in this country. Travel west of NY or south of DC to see it. The north east is pretty skinny.

3. Using BMI is making it hard to study the problem of obesity. How I loathe that measure.

Re: This is my burning ball of fury

[digitalsidhe.livejournal.com]

I was also going to post a comment to the effect that I can't understand why in the world anyone (aside from possibly quack "diet and fitness gurus" who are trying to push a particular agenda) is still using BMI. It's obviously a pretty worthless measure; it makes the average muscular athlete with 3% body fat look just as "overweight" as someone who's mostly flab.

But I think your points 1 and 3 do a better job than anything I was going to say.

Re: This is my burning ball of fury

[rigel.livejournal.com]

I ask out of genuine curiosity, not to contradict you or metahacker . . .

. . . do you have a better measure to suggest?

I agree with your point about BMI, actually.

Re: This is my burning ball of fury

[heinleinfan.livejournal.com]

Just for sake of discussion, and not to hijack a question directed at someone else, who could probably answer it better...I'm just rambly today...

I think that a major problem with "a better measure" is tied into our whole screwed up healthcare and health insurance system. A better measure would be a *full* measure of an individual's overall health, as opposed to an arbitrarily defined "Here's your label" type of measure. But things are too screwed up to offer most people that level of individualized health care, you know?

Re: This is my burning ball of fury

[metahacker.livejournal.com]

This is also an excellent point. "Here, have a number that says you are a bad person and will die early. Now leave, minus $120."

Re: This is my burning ball of fury

[brewergnome.livejournal.com]

It's hard, because you need a health measure, and then an actual fat measure, which to do properly requires a full body MRI to see where fat is getting deposited (skinny people can be fat if all their little fat is deposited around organs).

Re: This is my burning ball of fury

[benndragon.livejournal.com]

Which is why the people doing the study need 5-6 hours for a physical exam ;P. I wonder if I'll get a copy of that analysis that I can give to my doctor, just for his edification. . .

Re: This is my burning ball of fury

[brewergnome.livejournal.com]

THAT would be awesome.

Re: This is my burning ball of fury

[metahacker.livejournal.com]

One of the problems is one of the old "why are you looking near the lamppost for your lost keys?" "That's where the light is!" variety -- the things that are easier to measure get used because they're easier, not because they are accurate. (For BMI, everyone knows their height and weight and they are easy to get from corpses for mortality data)

When people talk about obesity they are generally talking about excess fat. There is some concern with overweight-ness from internal organs getting physically bigger, but I haven't heard one way or the other whether that is good, bad, or indifferent. There is some evidence that having extra muscle makes the heart work harder, but our society doesn't seem to care. Likewise extreme calorie restriction may greatly lengthen life, so having any body weight at all may be a liability, but few seem willing to eat the right 800 calories every day, and those guys may be wrong anyway.

Body fat percentage is harder to measure, but probably better for addressing the kind of obesity people are really concerned with. Ideally you'd get a full body composition breakdown, but I don't know how to measure that.

When I was a kid there was software that came with calipers and asked you to measure bits of yourself, and produced a reasonably accurate body fat % number. There are some scales that claim to do it based on some sort of electric current thing. And measuring your density (float you in a tub of water to get your volume, then divide) somehow gets to that number too, though I don't know how they differentiate bone vs. muscle vs. other internals. Google...

But the real kicker is that there's the question of 'is all excess fat bad' and 'is some excess fat (e.g. fat around organs vs. skin-layer fat) worse than others' and 'what is bad' anyway. I think we're all clear on the idea that having 50+ lbs of fat is probably obese, but what does that actually mean for health? This is what was implied in my #3. We don't know, and our classification schemes are making it hard to find out, because we lump together mortality of all people who are some weight X at some height X^2 * C.

Re: This is my burning ball of fury

[digitalsidhe.livejournal.com]

You beat me to it, and did it better, again. Thanks. I was basically going to suggest body fat percentage, and note that unfortunately, it's not as easy to measure as height and weight.

Re: This is my burning ball of fury

[heinleinfan.livejournal.com]

Somewhat related...my current burning ball of fury is nutrition in general and how food relates to the environment...which is, in many ways, tied to obesity.

We (we as in humans in general and especially americans) just *don't eat right at all* and we don't eat right because we've been listening too long to people who not only aren't looking for their keys in the right places, but are also being told by people who have a vested interest in keeping them under the light poles to look in those wrong places.

Like...nabisco has started replacing trans-fats with non-transfats in their stuff, so suddenly "Fritos corn chips" can have a label slapped on them saying they're heart healthy! The hell they're healthy, not for humans and not for the planet. But nabisco paid some scientists to do a study on transfats, and the scientists duly reported that yes, if Fritos had nontransfats instead, they'd be healthier!

GAH!

Re: This is my burning ball of fury

[plymouth.livejournal.com]

It turns a cubed-relation into a squared-relation

So, not that I think BMI is all that and a bag of chips, but a squared relation DOES actually make sense - when people gain weight they generally do it in two dimensions (they expand sideways and forwards/backwards) so you don't have to consider those dimensions as separate variables. Yes, I know, it's not monotonic and people will gain in different places first - butt, thighs, gut, whatever - but it all averages out to being the same in both horizontal dimensions, both of which are significantly smaller than the vertical dimension until we get to really extreme obesity.

Re: This is my burning ball of fury

[benndragon.livejournal.com]

Actually, there is a use for the BMI in the doctor's office. It should function as an initial observation indicating a need for further examination as part of a preventative strategy and/or possible avenues of exploration for the source of signs & symptoms if someone is already experiencing health problems. However, it seems to be treated as an if-then statement (if patient BMI exceeds $foo, then patient needs to lose weight; if patient BMI is less than $bar, then patient needs to gain weight) rather than a single clinical manifestation that is meaningless without context. But if a doctor is unlikely to realize it is merely an indicator that further examination is necessary, how the hell can a layman be expect to figure that out?

I'm not sure what the solution to this problem is. Replacing the BMI with some other measurement won't address it.

[rigel.livejournal.com]

. . . over half of Americans are overweight is based almost entire on this change . . .

What percentage of Americans would be considered overweight, d'you think, if this change hadn't been made? (In other words, what percent of Americans do you think are between BMI 27 and 25?)

Also: I'm impressed with your knowledge about such things, and willingness to wade through the citations and numbers. My eyes start to gloss over, and I'm glad someone is.

[benndragon.livejournal.com]

Sadly I can't say, because I can't get the full text of the paper that everyone points at when they say over half of Americans are overweight, at least not without paying for it (anyone with academic access to scientific papers willing to see if they can get a full copy for free?). All I can say is that the median BMI is 25.5. However, given the percentage of Americans with a BMI over 25 (59.4% of men, 50.7% of women) and that median number, I'm pretty darn sure more than half of Americans are below a BMI of 27.

[robertdfeinman.livejournal.com]

Michael Pollan has a new book out "In Defense of Food" in which he complains about the rise of "nutritionism", that is health claims not based upon any real evidence.

A good example is the rise of "carbs are bad" which may have now been replaced by "fats are bad" advice.

There are now schemes afoot to rate foods using stars or a numeric scale, but there is no objective measure as to what makes a food better. Factoring in things like added vitamins is mostly pointless. Generally speaking people in the US are not suffering from vitamin deficiency, so adding even more to some random product is not going to improve a person's health, but may improve a products "score".

As with all things, common sense and moderation are all that are really required.

[bikergeek.livejournal.com]

A good example is the rise of "carbs are bad" which may have now been replaced by "fats are bad" advice.

Ironic, because "carbs are bad" replaced the "fats are bad" that was parroted for much of the 70s, 80s, and 90s.

Part of the problem with accepting nutritional advice from anybody is the fact that the experts in the field seem to do a complete 180 every ten or so years, telling you that everything that you did for the last ten years based on their advice has been wrong and you need to do something else instead.

Like all the people who loaded up on margarine because "animal fats are bad". Now they found out that the trans-fats that margarine is laden with are worse for you than animal fats.

Then there were all the people who loaded up on pasta and rice in the 80s and 90s because "fats are bad but carbs are okay".

[perspicuity.livejournal.com]

too much of anything has always been bad. pretty much.

pollan's simple quote summing up one of his books makes a lot of sense.

but i'll note that at least to the end, Atkins never did a 180. he DID tone the message down a little, but right up until shuffled off, he was quite uppity about it.

me? well, i personally don't need to eat 150 lbs of sugar a year, a number atkins promoted some 9 years ago? it's probably more than that now. that is a LOT of sugar. esp compared with 50, 100, 150, 200 years ago. most of it these days corn syrup.

some days i wonder what the world, esp the USA would be like if we eliminated tobacco and corn. oh my yes. perhaps a few others, but those two in PARTICULAR.

"Eat food. Not too much. Mostly plants."

#

[brewergnome.livejournal.com]

Ugh, BMI.

I shudder to think where my BMI has been when I'm doing gymnastics. I know by the even older scale, I just passed into "moderately obese" this past week. Isn't that lovely? Yeah me, "moderately obese."

And the fat that causes the most danger? Not the flab, but the fat that "skinny" people get. The fat around their organs.

[perspicuity.livejournal.com]

oh, indeed... i have a large frame. i work out, and am fairly strong. i could be stronger in more rounded ways, but it's functional to what i like doing for the most part. i could stand to easily lose 30 lbs right now, but even at my most recent minimal weight, very trim, feeling nearly too skinny, i was at 199.

when i did gymnastics in college, i was 185 and super fit. i ran. i swam. i could hike all day. i could dance lift cute girls all day in the name of gymnastics :> i could walk on my hands (sigh). pushups until the cows came home. yar. also, pretty much ripped :)

went to my doctor for strep. they put me on a scale without my shoes, but with my typical loose baggy clothes on. < 190. measured my height. took my pulse (very low resting pulse rate, and still quite low). great blood pressure ranges.

he sat me down, and told me very seriously he was concerned about my weight, and said i should drop at least 20 lbs. i laughed. then i told him what i did at school for fitness. unicycling made my legs incredibly corded. best workout ever. as i was wearing shorts, i made a point of showing him.

this BMI stuff pretty much doesn't apply to people who are *fit* it seems.

i seem to recall that much of the actuarial data they have is based on civil war era soldiers. hungry, well exercised men. skinny but strong. great. nothing like most civilians, well, except the working class (which was a lot of them).

there's a tv show that reenacts a life style of 100+ years ago, pioneer valley? they take a regular family, and pretty much drop them in a cabin, and they get to live the life. so this regular guy, with 8+ hours of field work a day, eating pretty well, got all skinnied up. he thought he was sick or had parasites. eventually he got pretty damn taut, wirey, and a totally flat belly. he COULDN'T eat enough. heh. work work work.

last bit: a friend of mine "got away from it all", and went on walkabout in NZ for 3ish months, hiking with a backpack. always on the move. the change was dramatic. already somewhat fit and not in anyway fat, she lost 20+ lbs, and put on muscle to boot. very nice. nice enough, that i'm pondering doing just such a thing sometime before the decade is out. ponder ponder.

#

[brewergnome.livejournal.com]

Thank God mine didn't. I would have laughed at him.

I miss gymnastics.

But yeah, it's ridiculous. My Mom's overweight, I understand this, she understands this. But the unrealistic goals have made her basically give up. She has broad shoulders and relatively heavy bones (actually denser, runs in the family) and some muscle from shoving around goats and sheep (and hiking and backpacking and carrying kids up stairs). The weight they tell her she should be? Ridiculous.

[perspicuity.livejournal.com]

mmm, that reminds me, how do they easily determine bone density? i do some exercise (punching kicking jumping lots) and load bearing that i'm assuming is good for my bone density.

i've never broken anything even with several spectacular crashes off bikes and motorcycles and such. i wonder if my density is high?

#

[brewergnome.livejournal.com]

I'm trying to remember now and I'm blanking. I know MINE are dense 'cause I broke my arm. And instead of being the compound fracture it "should" have been, I got a compression fracture instead. And 45 minutes later there was already bone network growing across the break. My doctor was impressed.

[squibbon.livejournal.com]

I have major, major, problems with BMI as a measure. Also, I believe that the diet industry is to blame for many of the problems it claims to solve. Dieting wrecks your metabolism, and most people who lose weight on diets gain back more. So, someone can start off moderately "overweight" and end up weighing much more than they did to begin with if they just yo yo diet for a few years, which is quite common. If you google fat acceptance you can find a huge number of blogs and sites that talk about criticisms of the obesity panic.

[perspicuity.livejournal.com]

the dieting industry loves the no results part. it's great.

yo yo dieting is bad. people should practice weight management. permanently. the problem is: most people don't have a clue how.

oh, i'm aware of the criticisms of the so called obesity panic... can't quite get away from the fact people are probably heavier than they should be, and i'm talking carrying fat, not dense bones, or muscles, or metal implants.

also the "fat acceptance" thing. i used to weigh 290 apparently as a result of getting mono at 25 out college - it was pretty alarming. i didn't like or accept it. i set about to fix it. i'm constantly managing myself now, and sometimes i slip up, but it's a daily thing. i need to learn more, and mostly i need to workout at least an hour a day. motivation :)

imho, modern peoples is just to soft and they need to DO things, for hours a day. walk, dig, run, play, swim, be physical, get out there and do stuff. my profession (hacking) is esp bad for this.

#

[squibbon.livejournal.com]

I'm not arguing that at all. The thing is- a lot of thin people don't exercise either, and eat terribly. Those kinds of behaviors are bad for you no matter what you weigh. I'm well within what is considered a healthy weight, even by BMI standards, but I could still really stand to make some changes to the way I eat and to my activity level. Good for you for making a change that was important to you, and for feeling good about it. The point of fat acceptance, as I understand it isn't that everyone should just sit around and do nothing, it's that no matter what someone's lifestyle is like, or what their size is, they still deserve respect, and the self hatred that fat people are often encouraged to feel really doesn't get anyone anywhere.

[perspicuity.livejournal.com]

a lot of thin people aren't very healthy either. they eat terribly and well, there you go.

i know some skinny folx that get "beat up" for being the way they are too. go figure. i'd like to see "body acceptance". people are what they are and do what they do. "people come in people shaped packages"

similar with smoking. people wanna smoke? great. they shouldn't inflict it on me, nor expect me to love them for/because-of it, but i'll accept it's their deal for the most part, not mine.

unfortunately, pick a thing about oneself, and there's a self hatred for it. fat, skinny, old, young, skin, hair, teeth, eyes, hands, feet, bones and organs. hah.

people just ain't rational :P

#

[squibbon.livejournal.com]

Yeah, I've ranged from being pretty skinny to mildly/arguably overweight, the changes were mostly related to medication rather than lifestyle stuff. I actually found that people felt a lot freer to say mean things to me when I was very skinny, and a lot of it came from guys. Most men know better than to say negative things about a woman being overweight especially if they're interested in her, but for some reason calling me "skeletal" was OK (and actually, I wasn't underweight by a long shot.) It was also weird to have everyone around me assume I had been dieting when really I was chowing down on high calorie stuff like nuts and food with a ton of olive oil and protein shakes to keep from losing too much weight too fast.

Now I live in a neighborhood where most of the women I see on the street are a size 4 or below, and I'm on a different set of meds and gaining back some weight. Nobody is saying anything overt, but I do feel uncomfortable sometimes despite currently being around the middle of the BMI range. Even when I know I'm still a healthy weight, and that gaining some back is OK, it's still hard on me when I have to go shopping for larger jeans. You just can't win.

[squibbon.livejournal.com]

Just to clarify- none of the meds I'm talking about are weight loss drugs even remotely, I just tend to get the strange side effects that nobody else does.

[watercolorblue.livejournal.com]

BMI is basically BS. I'm not even going to discuss my number now, but even at my reasonably fit college weight, I was most definitely into the Overweight bracket according to BMI and American standards. I have broad shoulders and an Eastern European build. A lto of it's muscle. There are reasonable goals for my own weight loss, and there's what the government recommends...and they are definitely not consistent with one another.