Editore"s Note
Tilting at Windmills

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September 11, 2007
By: Kevin Drum

OVERSOLD....A reader writes to tell me I've become obsessed with Iraq. And he's right. It seems appropriate this week, but he's still right. So here's Paul Campos on whether or not it's OK to be overweight:

The story is simple: That it's well-established scientific fact that being "overweight" — that is, having a body mass index figure of between 25 and 30 — is, in the words of Harvard professors Walter Willett and Meir Stampfer, "a major contributor to morbidity and mortality."

....It's difficult to exaggerate the extent to which the actual scientific evidence fails to support any of this. In fact, the current evidence suggests that what the Harvard crew is saying is not merely false, but closer to the precise opposite of the truth. For the most part, the so-called "overweight" BMI range doesn't even correlate with overall increased health risk.

Basically, I accept Campos's argument. Being moderately overweight, in and of itself, won't kill you. The evidence on that score seems pretty compelling.

But I still have some questions. First: being overweight is associated with developing diabetes, isn't it? And this is a very bad thing. Second: in 99% of the cases, being overweight is the result of eating too much fatty food. And fatty foods are bad for your serum cholesterol level and likely to increase the risk of a heart attack. It's possible to have a high BMI even though your diet is fine, but let's face it: that's not usually the case. And third: being overweight stresses your back and your knees and your other joints and makes you less likely to exercise. And lack of exercise really is damaging to your health.

Now, I'm no expert in this stuff, and I might be off base here. And none of it is an excuse for medical researchers to misstate the epidemiological research on weight. Still, saying there's no increased health risk at all to being overweight is a stretch, isn't it? Anybody want to weigh in on this?

Kevin Drum 2:37 PM Permalink | Trackbacks | Comments (79)

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Comments

Look around at the 90-year-olds. How many of them are overweight?

Posted by: Quaker in a Basement on September 11, 2007 at 2:45 PM | PERMALINK

"the Cambridge cabal" ??

duh, the Harvard School of Public Health isn't in Cambridge. It's in Boston. Tell Campos to get his facts straight.

Posted by: lee on September 11, 2007 at 2:46 PM | PERMALINK

More likely if you are of 'proper' weight in our society, you are probably very sick!

Chemo, Bulimia, Cancer...

Posted by: MobiusKlein on September 11, 2007 at 2:47 PM | PERMALINK

Actually more than you might imagine. Ever hang out in a nursing home?

Posted by: Ara on September 11, 2007 at 2:47 PM | PERMALINK

Look around at the 90-year-olds. How many of them are overweight?

More than you might imagine. Hang out in a nursing home and you'll see what I mean.

Posted by: Ara on September 11, 2007 at 2:49 PM | PERMALINK

There is also pretty compelling data that shows reduction in cancer mortality in patients on a very low calorie diet (under 1000 calories/day). This effect was first observed in lab rats. The theory is that burning calories creates toxins that increase the odds of a genetic event that will lead to cancer. I'm not sure how all these studies fit together, but it seems that the answer is more and larger studies.

Posted by: Pheo on September 11, 2007 at 2:52 PM | PERMALINK

But I still have some questions. First: being overweight is associated with developing diabetes, isn't it?

No. Being overweight to the point of obesity is often a contributing factor to getting diabetes in later life. If you're carrying ten or fifteen extra pounds, no worries. Then your major problem may just be unsightliness in tight and/or revealing clothing.

(Got that, Kevin? No more short-shorts and crop tops.)

Posted by: JeffII on September 11, 2007 at 2:54 PM | PERMALINK

How about correlation of weight with class? Every time I visit the US it seems like fatness has become a more clear and inviolable marker of the class barrier: urban vs. rural, white/asian vs. black/hispanic, rich vs. poor, educated vs. uneducated.

Posted by: brooksfoe on September 11, 2007 at 2:54 PM | PERMALINK

Campos is a law professor? I'm really not interested in what he has to say about this, sorry. If there are some public health people who have something to say about this, great. But not a law professor with no training in empirical research.

Posted by: BRussell on September 11, 2007 at 2:56 PM | PERMALINK

America is the largest contributor to morbidity and mortality in Iraq.

Posted by: Brojo on September 11, 2007 at 2:59 PM | PERMALINK

How about correlation of weight with class? Every time I visit the US it seems like fatness has become a more clear and inviolable marker of the class barrier: urban vs. rural, white/asian vs. black/hispanic, rich vs. poor, educated vs. uneducated. Posted by: brooksfoe

Bingo! I think in the most recent fat report I heard on NPR that either Alabama or Mississippi led the nation in obesity. (Dumb, racist, fat, conservative.)

Posted by: JeffII on September 11, 2007 at 3:00 PM | PERMALINK

Scientific American just had an issue about this: http://www.sciam.com/issue.cfm?issueDate=Sep-07

Posted by: Clint on September 11, 2007 at 3:07 PM | PERMALINK

according to BMI this guy is overweight. does he look fat to you?

Posted by: supersaurus on September 11, 2007 at 3:07 PM | PERMALINK

There was a good survey in the latest (or the one before it) Scientific American. Pretty convincing:

http://tinyurl.com/2o24mo

Posted by: Gore/Edwards 08 on September 11, 2007 at 3:08 PM | PERMALINK

Campos is knocking the crap out of a straw man. It is percentage of body fat that matters, not BMI. BMI is not an accurate measure of body fat percentage. His "research" is a joke. He is telling people what they want to hear and being contrarian to make a buck.

Posted by: Orson on September 11, 2007 at 3:08 PM | PERMALINK

Three things.

First, be very, very careful about definitions. You appear to use "overweight" interchangeably to mean either (1) in a metaphysical sense, heavier than a medically-preferred weight, or (2) a BMI between 25 and 30. The problem with this is that the two definitions aren't necessarily the same -- in fact, they're probably not. Indeed, in the not-too-distant-past, "overweight" was defined as a BMI between 27 and 31 (roughly -- it was different for men and women). So, for the vast majority of people, is there some magical "overweight" number at which your health begins to suffer? Yes. But that very well might be different from a BMI of 25 (or 30 or whatever). And using the same terminology to refer to that magical number and a BMI of 25 is simply bunk.

Second, it's worth noting that many health professionals and organizations are going beyond the recommendation to keep your weight within the "normal" range. They are going so far as to recommend that you try to get as low in the normal range as possible. The problem is that the lower bound of "normal" is actually unhealthily thin for the vast majority of people. It's 129 pounds for the average 5'10" man. That's simply wrong. My guess is that probably only 5-10% of 5'10" men could drop that low without significant adverse health consequences (heart disease, eating disorder, etc.). That height/weight ration is probably below the height/weight ratios of ultra-endurance athletes -- to give an example, I'm 5'9" and a good-for-an-amateur marathoner (sub-3:00, multiple open Boston qualifier, etc.). My racing weight is in the 143-146 range. Those little, tiny Kenyans that you see win all of the major marathons are usually around 5'6"-5'8" and 120 pounds or so. So based on the BS recommendations, THEY COULD STAND TO LOSE FEW POUNDS. This is wrong to the point of being dangerous.

Third, BMI was never meant to be diagnostic for individuals. Body fat percentage, waist-to-hip ratio, etc., are much better for that. Yet doctors have begun to rely on it as diagnostic (i.e., you go in, and if your BMI is above a certain number, you are told to lose weight). That probably causes some eating disorders and negative health consequences at the margins, and it probably hides some weight problems that could be found without the overly simplistic crutch. It's akin to making medical recommendations based solely on total cholesterol numbers. If someone has an abnormally high HDL number but an acceptable LDL number, then they are totally fine, and any course of action will be at best have no health effect, and possibly subject them to unnecessary side effects for no health gains.

(Incidentally, Kevin, eating fat does not necessarily raise LDL numbers. Eating saturated fats does. In fact, if you recommended someone cut their fats to cut cholesterol numbers, and they cut unsaturated fat intake (nuts, olive oil, canola, fish, etc.), then they may well end up decreasing their Total/HDL ratio, thus causing a negative health effect.)

Posted by: Joe on September 11, 2007 at 3:09 PM | PERMALINK

Ara, the percentage of adults over 90 that is overweight is quite small relative to other age groups. This is based on both self report/assessment and actual measurement surveys. Don't overstate the anecdotal evidence you may have seen.

Posted by: GOD on September 11, 2007 at 3:10 PM | PERMALINK

Sorry, Clint. You must have posted while I was looking for the direct link.

Posted by: Gore/Edwards 08 on September 11, 2007 at 3:10 PM | PERMALINK

BRussell:
Campos is a clear thinker, whether he is an epidemiologist or not is little concern in deciding what the studies actually say.

Kevin:
Campos does not say that there was no risk, he simply looked at the data and said that the data show that
the best mortality results are for an unexpected group. What a novel idea: Looking at the data and thinking clearly. He then asks the Harvard crew to do the same. Deal with it, rather than lie about it.

He also said that the best results occur at the border between 'normal' and 'somewhat obese'.
The morbidly obese range (BMI > 31?) clearly has lots of problems.

Posted by: catclub on September 11, 2007 at 3:11 PM | PERMALINK

Didn't TNR publish something very similar to this a few months ago?

I believe that if you eat well and exercise consistently, you will be in good shape.

My personal experience of following this course of action is that I lost 18 pounds.

I've read there are people who eat primarily healthy foods and exercise a lot and remain in the overweight range. I've just never met any.

Posted by: lyofbrooklyn on September 11, 2007 at 3:13 PM | PERMALINK

It's clear that Joe has the right interpretation of the Campos article, but to put it in a bit of a tighter summary:

Campos is not arguing that being overweight is good for you. He is arguing that, since the overwhelming majority of studies have found lower mortality among the group at the upper limit of "normal" and lower limit of "overweight," the BMI scales/"normal" weight ranges are calibrated incorrectly.

Move "normal" weight up 20 pounds and you are probably in the right weight range for optimal health. Campos is definitely not saying that being fat is good for you.

Posted by: Aaron on September 11, 2007 at 3:14 PM | PERMALINK

There is also pretty compelling data that shows reduction in cancer mortality in patients on a very low calorie diet (under 1000 calories/day). This effect was first observed in lab rats. The theory is that burning calories creates toxins that increase the odds of a genetic event that will lead to cancer. Posted by: Pheo

Some study may indeed discuss this, but what you've written doesn't even make sense. If you are thin and on a reduced diet to begin with (compared to the average American), you aren't necessarily "burning (more) calories." This also doesn't address the really active who can consume more than the recommended 2,000 cal./day and will neither hurt his or her health nor gain weight.

And being a cancer survivor (knock on a woody - we're all survivors until we die of something else), I've never read anything about cancer and toxins from burning calories, excessive or otherwise.

Free radicals, which are posited as possibly attacking otherwise healthy cells and weakening them, exist independent of burning stored calories, and can be dealt with by increasing certain amino acids and nutrients (vitamin C, selenium, Co-Q 10) that "scavenge" free radicals.

So far as I know, there is no correlation between BM (that's body mass, Kevin, don't ban me for bad language) and cancer (though a fatty liver isn't good under any circumstances). The rat studies were looking, if I'm not mistaken, at general longevity, not a reduction of the incidence of cancer because of reduced caloric intake.

Posted by: JeffII on September 11, 2007 at 3:17 PM | PERMALINK

The BMI is a joke. It says I am morbidly obese, when in fact I am fit and can lift a bus over my head.

This reminds me of the smoking thing. The odds of a person getting lung cancer is fairly low, but smoking damages all kinds of stuff unrelated to cancer.

Posted by: BombIranForChrist on September 11, 2007 at 3:18 PM | PERMALINK

"Bingo! I think in the most recent fat report I heard on NPR that either Alabama or Mississippi led the nation in obesity. (Dumb, racist, fat, conservative.)" Not that I support dumb, racist, fat, conservatives, but Alabama and Mississippi lead primarily because of their African-American populations as the highest in the nation, and their rates of obesity are easily the highest of any group.


Posted by: RollaMO on September 11, 2007 at 3:20 PM | PERMALINK

"It's clear that Joe has the right interpretation of the Campos article, but to put it in a bit of a tighter summary:

Campos is not arguing that being overweight is good for you. He is arguing that, since the overwhelming majority of studies have found lower mortality among the group at the upper limit of "normal" and lower limit of "overweight," the BMI scales/"normal" weight ranges are calibrated incorrectly."

I actually haven't read Campos's article. I have some problems with what he says generally.* However, I agree with your summary. The biggest problem with all of this is that -- even setting individual body type variation aside -- the BMI scales are simply calibrated wrong, which causes anxiety for those in the high 20s and substantial health problems for many/most in the high teens.

*Long story short: I think he substantially underestimates the negative health effects of a higher BMI among young adults, though he is absolutely correct that (1) these problems vanish as you get into middle age (where a BMI over 25 is actually a predictor of an increased life expectancy), and (2) the danger isn't the higher BMIs themselves (we're talking about the 25-32 level), but rather, the tendency of a 25 year-old with a BMI of 28 to become a 40 year-old with a BMI of 38.

Posted by: Joe on September 11, 2007 at 3:23 PM | PERMALINK

My summary of the comments (and my own perusal of literature and the world): there's room to argue about how much weight it is safe to carry, but at some point (and one that a lot of people have passed) it becomes unhealthy.

I'd hasten to add, you can't confine your thinking here to morbidity measured in years of life. It's very important to think about quality of life. As someone who has seen a number of family members struggle with Type II diabetes and severely compromised mobility (up to and including joint replacements) I can tell you that carrying all that extra weight around may be no big deal when you're 30 but it gets to be a pretty serious problem once you push 60.

Posted by: left-handed screwdriver on September 11, 2007 at 3:23 PM | PERMALINK

"Anybody want to weigh in on this?"

punners must burn in hell.

Posted by: Tlaloc on September 11, 2007 at 3:25 PM | PERMALINK

Kevin, this is an interesting diversion from the big news of the week/month/year (Petraeus/The Magical September Report/Iraq in general), but your reader who said you were obsessing about Iraq is an idiot. It's *OKAY* to obsess about Iraq, because it's a big fucking deal.

Now obsess again, or I shall taunt you a second time...

Posted by: Chris on September 11, 2007 at 3:30 PM | PERMALINK

i very easily lost 25 lbs. by cutting out refined sugar and flour and exercising on an elliptical machine for 30 minutes 3 times a week. i cannot overstate how much better i feel and in ways i did not expect...

eat less crap and raise your heart rate regularly!!

Posted by: travy on September 11, 2007 at 3:32 PM | PERMALINK

A lower BMI may be associated with smoking, which skews things considerably.

And I've hung out in plenty of nursing homes, and never once seen an overweight 90-year old. Quite the opposite.

Posted by: KathyF on September 11, 2007 at 3:36 PM | PERMALINK

Don't confuse Public Health with medicine. I remember meeting a few MPHs from an Ivy League school who were driving cabs in New Haven.

Posted by: gregor on September 11, 2007 at 3:37 PM | PERMALINK

The odds of a person getting lung cancer is fairly low, but smoking damages all kinds of stuff unrelated to cancer. Posted by: BombIranForChrist

Yeah. Years ago The Atlantic had a wonderfully contrarian article about cancer and smoking. Something like 90% of people who smoke don't die of lung cancer at age forty or even age sixty. In fact, most people who smoke for most or all of their lives don't die of lung cancer or emphysema. The direct affects of cigarette smoke on the lungs is grossly overstated. It is the secondary effects.

Not that I endorse smoking (though I gave up cigars when I was diagnosed with melanoma). Cigarette smoke (save for pure Turkish tobacco) smells like shit because of all the additives (sulfur anyone?), and turns your teeth yellow.

Posted by: JeffII on September 11, 2007 at 3:37 PM | PERMALINK

It's a long time since I've dealt with quantitative methodology, but I think Kevin is getting at a basic issue of interpretation that is often overlooked. Maybe obesity doesn't kill you if you control for diabetes, blood pressure, etc. Normally, controlling for different variables is a valid and necessary scientific procedure to uncover the "pure" relationship between A and B. But it can be misleading if A works through other variables to influence B. In that case, you don't want to control for x, y and z: you're just interested in knowing if A (obesity) increases B (mortality), whether or not it works through intermediate variables.

Posted by: Tony Greco on September 11, 2007 at 3:37 PM | PERMALINK

Re fat as a class indicator – I don’t know but on the rare occasions I go to Wal-Mart I get the creeps seeing all the over-weight people.

The impact of growing numbers of morbidly obese patients on the health care industry is significant. Just from the technical side, hospital beds are being redesigned for loads up to 1000 lbs and special extra-long (55cm) arthroscopic staplers are now made for use on the morbidly obese.

Posted by: fafner1 on September 11, 2007 at 3:43 PM | PERMALINK

"Second: in 99% of the cases, being overweight is the result of eating too much fatty food."

Also, this is unquivocally wrong. In 100% of cases, being overweight* is the result of eating more calories than you burn. There are many, many factors that go into this. Basal metabolism rate**, calories ingested, calories burned through activity, efficiency of your digestive system, etc. Eating fatty food contributes to one of these factors (calories in), but it's not the only one (also contributing is how many non-fat calories you eat), and it's only one factor in any event. To put it succinctly, many overweight people have low fat intakes -- far more than 1%. Some eat too many protein or carb calories, some eat just enough of everything but never exercise, and some unfortunate souls just have a really crappy basal metabolism.

* I'm using the metaphysical "unhealthily heavy" definition here, not the BMI-base one.

** Which is primarily determined by genetics.

Posted by: Joe on September 11, 2007 at 3:44 PM | PERMALINK

Just look at all the obese members of Congress, such as former Speaker of the House, Dennis Hastert. Scarfing down all those free meals at lobbyists' expense, they've certainly endangered our country's health and well-being.

Posted by: Donald from Hawaii on September 11, 2007 at 3:48 PM | PERMALINK

Maybe obesity doesn't kill you if you control for diabetes, blood pressure, etc. Normally, controlling for different variables . . . Posted by: Tony Greco

If you're controlling (for) the "variables," in all likelihood you aren't fat to begin with. It's true that genetically some people will have a predisposition to poor insulin production or high blood pressure or high "bad" cholesterol. But none of these things have to do with being fat. Juvenile diabetics are usually look anorexic.

Posted by: JeffII on September 11, 2007 at 3:49 PM | PERMALINK

This is science, not politics. Why should I listen to a law professor (Paul Campos) instead of two epidemiologists (Walter Willett and Meir Stampfer)?

Posted by: Tom Veil on September 11, 2007 at 3:53 PM | PERMALINK

What I got from the article is that the Harvard people and JAMA people are having a bit of a food fight, and the Harvard people seem to be fudging the numbers or disregarding them altogether.

I don't think anyone claims that obesity is desirable. But the data seems to show that being slightly overweight, by current definition, may lead to a longer life than being of normal weight. The simplest solution would be to make a slight adjustment to the charts for recommended weights. But that is not happening.

By the way, the TNR article cites the Scientific American article, and not particularly favorably.

Posted by: JJF on September 11, 2007 at 3:58 PM | PERMALINK

I recently heard (though I'd have to look it up for the source) about a study that found that going through yo-yo weight fluctuations from dieting was also pretty unhealthy. Unfortunately, most people want the quickest fix possible, and they want to do it without permanently changing lifestyle habits, and that just isn't a good combination. But hey, it's sure profitable for the weightloss industry.

Posted by: Royko on September 11, 2007 at 3:59 PM | PERMALINK

Years ago The Atlantic had a wonderfully contrarian article about cancer and smoking. Something like 90% of people who smoke don't die of lung cancer at age forty or even age sixty. In fact, most people who smoke for most or all of their lives don't die of lung cancer or emphysema.

My recollection is that one's chance of getting lung cancer if one smokes is about 1 in 25, and dramatically less if one doesn't (maybe one in 100 or less).

Why you might think those are perfectly OK odds I really don't get.

Posted by: frankly0 on September 11, 2007 at 4:08 PM | PERMALINK

according to BMI this guy is overweight. does he look fat to you? Posted by: supersaurus on September 11, 2007 at 3:07 PM | PERMALINK

That's not the word that comes to mind.

But as others have said upthread -- the bmi is baloney without factoring in body fat, cholesterol, diet, exercise. And is not muscle weight heavier then fat? According to the bmi, at 6'2" and 205, I am overweight. But I have been a gym rat for 20 years doing lifting/cardio. I spend 5 hours a week climbing a 30% treadmill 13,000 feet, in 13 miles, and burning 5000 calories. I seriously doubt that I need worry about my weight.

My drinking and smoking on the other hand...

Posted by: e henry thripshaw on September 11, 2007 at 4:13 PM | PERMALINK

"My recollection is that one's chance of getting lung cancer if one smokes is about 1 in 25, and dramatically less if one doesn't (maybe one in 100 or less)."

The devil is in the details -- how much did one smoke? For heavy smokers (30 pack-years), it's about 1 in 7. This is 15 to 25 times greater than nonsmokers (depending if the nonsmoker is a man or woman).

Posted by: Joe on September 11, 2007 at 4:17 PM | PERMALINK

My argument is that some studies suggest that low-calorie diets result in longer life and less cancer beyond what is expected from weight alone. If someone consumes 3000 calories and burns 1000 calories through exercise, he is not as well off as someone who just eats 2000 calories.

Here is a JAMA article linking lower caloric intake with reduced breast cancer risk in humans:

Article abstract here

In this case, the likely culprit is lower estrogen (from lower body fat) resulting in lower incidence of breast cancer. Mortality from other cancers could increase, I don't know.

Many other studies come up on a search of Pubmed that link low calorie intake to both longevity and decreased tumor incidence. Many of the studies are on rodents, but some are studies of human populations.

Posted by: Pheo on September 11, 2007 at 4:22 PM | PERMALINK

For heavy smokers (30 pack-years), it's about 1 in 7.

Yikes! That's even worse than I thought. That's about the same as Russian Roulette, without any of the thrill.

Posted by: frankly0 on September 11, 2007 at 4:24 PM | PERMALINK

My argument is that some studies suggest that low-calorie diets result in longer life and less cancer beyond what is expected from weight alone.

Personally, I place my faith in the magical properties of resveratrol.

Posted by: frankly0 on September 11, 2007 at 4:26 PM | PERMALINK

If someone consumes 3000 calories and burns 1000 calories through exercise, he is not as well off as someone who just eats 2000 calories.

You've got to have more than one citation to support this. The notion that no exercise is better than some exercise defies common sense much less many many studies.

Posted by: Edo on September 11, 2007 at 4:29 PM | PERMALINK

"You've got to have more than one citation to support this. The notion that no exercise is better than some exercise defies common sense much less many many studies."

I'm too lazy to look up the cite, but there is some truth to what he says, though he mangles it with his example.

There is a well-documented literature on rats and other mammals (but not humans) suggesting that an ultra-low calorie diet can substantially increase life expectancy. Basically, the theory goes that mammals' bodies, when they are experiencing a time of famine or sustained deprivation, experience a fundamental metabolic change. Basically, cell division slows down drastically. This reduces a lot of the negative health effects of aging (basically, it's hard for cells to mutate if they divide much more slowly, which reduces cancer rates, and the little cellular suicide gene that activates after so many divisions is delayed substantially for obvious reasons). It's been proven with rats, and there is some indication that it would work for humans as well. We're basically talking increased life expectancies of 25% or so, if memory serves.

BUT (and it's a big but), an ultra-low calorie diet is about as bad as what it sounds like. We're not talking 2000 or even 1500 calories a day. More like 1000-1200 calories/day for the rest of your life. That's incredibly restrictive, and to put it bluntly, a lot of people really aren't convinced that the tradeoff of being on a hugely restrictive diet for many, many years is worth it.

So, anyway, it probably is better to eat 3000 calories and burn 1000 than to eat 2000 calories and not exercise. It may not, however, be better to eat 3000 calories and burn 2000 than it is to eat 1000 calories and not exercise.

Posted by: Joe on September 11, 2007 at 4:47 PM | PERMALINK

Yeah, I'm quite adept at mangling things. And you are right, the ultra-low calorie diet that has been studied would result in a longer life of misery. I think the study participants were actually restricted to something like 800 calories. Crazy.

Thanks for backing me up, Joe (I think).

Posted by: Pheo on September 11, 2007 at 4:52 PM | PERMALINK

BMI is useless for anyone who is either tall or muscular. I'm in terrific shape, no one would think I was remotely overweight by looking at me, and my BMI is 27, largely because I lift. I suppose next my doctor will tell me to spend less time in the gym.

Posted by: dal20402 on September 11, 2007 at 4:55 PM | PERMALINK

This research is what I do for a living, and I work at the Harvard Medical School. The basic story is that having a BMI over 30 is certainly bad for your health. Having a BMI between 25 and 30 has, if anything, a very small effect, and no research to date has shown conclusively that it has any, as small errors in model specification can change the results.

Posted by: Pete on September 11, 2007 at 5:02 PM | PERMALINK

"I think the study participants were actually restricted to something like 800 calories. Crazy."

It's been a few years since I read about it, so that is probably right. I distinctly remember reading that many participants ate only raw vegetables, pretty much all day long -- eating a bunch of low calorie stuff that filled the belly (albeit with fiber and water) was the only way to deal with the constant hunger.

I recall that scientists were seeing if there was some way to flip on the famine gene without actually having to undergo such a horrible experience, but I haven't ever heard about any progress on this.

Posted by: Joe on September 11, 2007 at 5:03 PM | PERMALINK

If someone consumes 3000 calories and burns 1000 calories through exercise, he is not as well off as someone who just eats 2000 calories.

The human adult needs around 2,000 cal/day for normal activity (including sleeping). If you are consuming approximately 3,000 a day, burning off 1,000 of this in exercise, which is saying a lot (downhill skiing burns 3-5,000/day - this is how I justify a dramatic increase in alcohol consumption over a weeks' vacation), you probably aren't gaining weight and may actually be losing fat depending on what and when you are eating. More important, you are doing a world of good to you cardio-vascular system and bone density (if you are lifting some weights in this regimen). So, no. It's not better nor even the same.

Sitting on your ass all day long, as most of us do (unless you work in agriculture or construction), does squat for your body. Moderate exercise at least three times a week (a mix of cardio, weight lifting and core exercises) is important. Even walking a bit is better than nothing. But otherwise, your simple (-minded) math just doesn't add up.

Posted by: JeffII on September 11, 2007 at 5:04 PM | PERMALINK

*

Posted by: mhr on September 11, 2007 at 5:07 PM | PERMALINK

BMI is useless . . . I'm in terrific shape, no one would think I was remotely overweight by looking at me, and my BMI is 27, largely because I lift. I suppose next my doctor will tell me to spend less time in the gym.
Posted by: dal20402

It depends. Are you one of those lunkheads with a razor wire tat on your bicep who spends a lot of time lifting in front of mirrors and is so muscle-bound he has a problem wiping his ass? If not, your "next doctor" will probably say you're okay.

Posted by: JeffII on September 11, 2007 at 5:17 PM | PERMALINK

JeffII. Why don't you go to pubmed and search for some of the research before you go all anecdotal on my ass? Sorry I don't have the time to write an entire review article summarizing their data, even if people will label me simple-minded.

The data seem to suggest that people who maintain their weight by restricting calories instead of pigging out and then exercising the calories off may be better off. Joe is correct in pointing out that the studies thus far show the survival benefit of an ultra-low calorie (i.e., miserable) diet. I'd be interested in studies examining the gains in more reasonable caloric restriction versus weight maintenance through exercise.

Posted by: Pheo on September 11, 2007 at 5:19 PM | PERMALINK

I recall that scientists were seeing if there was some way to flip on the famine gene without actually having to undergo such a horrible experience, but I haven't ever heard about any progress on this.

Well, actually, some researchers are claiming that resveratrol does this, though that's in dispute.

Resveratrol and life extension.

Posted by: frankly0 on September 11, 2007 at 5:27 PM | PERMALINK

Anecdotal evidence of female movie stars and socialites, both of whom are famous for being thin, suggests that as long as you don't OD on drugs being thin makes you die of old age: Katherine Hepburn, Mary Pickford, Marlene Dietrich, and now Jane Wyman all died in their 90's, and Brooke Astor just died at 105. Being too rich and too thin evidently is good for you.

Posted by: Diana on September 11, 2007 at 5:48 PM | PERMALINK

JeffII. Why don't you go to pubmed and search for some of the research before you go all anecdotal on my ass?

I wasn't "go(ing) all anecdotal on (your) ass." I was stating fact. If you doubt it, you look it up. And I was being polite calling your calculus about the supposed health benefits of consuming only 2,000 cal/ day simple-minded. Actually, it's pretty retarded since you don't bother to indicate what your 2,000 cal. is composed of. Given your post, you probably don't know that it's actually possible to lose weight eating 5,000 cal./day of only protein coupled with physical labor. On the other hand, your average over-weight cube denizen/online gamer will steadily gain weight if his or her 2,000 cal./day diet consisted entirely of Mountain Dew, Hagen Daz and Doritos. It is not merely a matter of how much you eat. What you eat is just as important.

The data seem to suggest that people who maintain their weight by restricting calories instead of pigging out and then exercising the calories off may be better off.

Yes. And geriatric studies show that simply eating "sensibly" isn't enough. Exercise is still important, and you don't maintain sufficient bone density by merely choosing the heart healthy lunch special over the double patty bacon burger with cheese. Plus the fact, if you do get off your ass you can consume pretty much as much of the "fun" foods as you like instead of having to eat "sensibly" all the time. But if you're a big fan of dry whole wheat toast and carrot sticks three times a day . . .

Joe is correct in pointing out that the studies thus far show the survival benefit of an ultra-low calorie (i.e., miserable) diet. I'd be interested in studies examining the gains in more reasonable caloric restriction versus weight maintenance through exercise. Posted by: Pheo

You're the one who introduced the arbitrary 1,000 extra calories for your example, which I guess is what you define as "pigging out," though again without characterizing these 1,000 extra calories. I haven't advocated one diet or the other, and I acknowledge up thread the validity of studies showing that, in mice, reduced caloric intake increases longevity. To my knowledge, though, no one has caged any humans and fed them a reduced diet to see how much longer they've lived. And until they do that medical science will never be able to control for all the variables to definitively conclude that diet alone increases lifespan.

Even if one exercises vigorously two or three days a week, you don't need to boost your caloric intake dramatically to keep from wasting away, and no where in my post did I advocate this. I merely explained that one can consume more than 2,000 cal./day and not damage his or her health, and may even need to do so just to get through the day (again, manual laborers, professional athletes, active duty military).

Look, I'm really sorry you got cut from the jr. high wrestling team and were always picked last for dodge ball, but don't put words in my mouth.

Posted by: JeffII on September 11, 2007 at 6:11 PM | PERMALINK

Kevin,

Thanks for the link. Addressing your questions:

(1) An association with diabetes begins to appear at BMI 22, i.e., toward the low end of the "normal" weight range. The problems with citing this as evidence for what Willett is saying (that everybody should try to be in the low end of the "normal" range to optimize health) are many. I'll list just a few. First, there are many diseases that correlate with lower weight, including lung cancer (the single biggest killing cancer), osteoperosis, most of the major respiratory diseases, anemia, and many others. Nobody argues that people ought to try to get fat to avoid lung cancer, and rightly so. But they make the equally questionable argument that they ought to try to get thin to avoid diabetes. Type II diabetes is a complex condition, closely associated with so-called metabolic syndrome. It's unclear to what extent obesity causes diabetes as opposed to diabetes causing obesity. Furthermore, the most successful intervention studies have shown that lifestyle changes that lessen diabetes risk do so without regard to whether these changes produce any significant weight loss (they usually don't). This is just one of many pieces of evidence that lifestyle, not weight, is the relevant variable.

(2) The statement that 99% of so-called overweight is caused by eating too much fatty food has no basis in the medical literature. This is one of those rampant "common sense" beliefs with no empirical support.

(3) We don't know, even roughly speaking, how many people would have a BMI between 18.5 and 24.9 if everybody had an optimal lifestyle. Furthermore, there's no rational basis for defining that range as "normal" or "healthy." It doesn't correlate with the best health, and the idea that most people would weigh that much if they didn't sit around watching TV and eating Doritos all day (again, another "common sense" view) is likewise empirically unsupported.

(4) Lack of exercise is bad for health, and high weight makes it more difficult to exercise. This is true. However, we don't know how to make fat people thin. Let me repeat that: we don't know how to make fat people thin. Yet another common sense belief, that telling people to eat less and exercise more will result in significant long-term weight loss, has been definitively refuted to the extent that any empirical claim can be. What we should be telling fat people is the same thing we should be telling thin people and everybody in between, which is that being active and eating a balanced diet are good things. What we should not be telling them is that doing these things will give them a BMI in the government approved range. We know that for, conservatively speaking, tens of millions of people, it doesn't and it won't.

(5) There is no increased overall health risk with having a BMI of 25 to 30. Thus the overweight category is completely bogus. It makes no sense to call such people (who compromise the majority of Americans who are classified by the government as weighing "too much" overweight. They're not overweight in any medically valid sense. I don't claim that there's no health risk associated with high weights (well above the phony "overweight" range). What to do about that is another matter. Our government and culture's Plan A, which is to hector fat people about how they should be thin, is a strategy that has never worked, isn't working now, and gives no prospect of working at any time in the future.

Come to think of it, that sort of reminds me of our attitude toward a certain problem in Mesopotamia . . .

Posted by: Paul Campos on September 11, 2007 at 6:12 PM | PERMALINK

JeffII,

As far as I can tell, your post is all ad hominems, assumptions, and anecdotes. I took the time to list one recent reference from the Journal of the American Medical Association. You could try to refute what I said instead of calling me names.

I never said exercise was bad. I never meant to address the benefits of relative proportions of carbs vs. fat vs. protein. The early studies in humans are suggestive of certain things but are not definitive. That's how science works. Someone will eventually do a larger study looking at the benefits of more modest calorie restriction. And I never said that my interpretations of the studies were absolutely right (as you so adroitly highlighted in my above statement). I happy acknowledged that Joe had it right (regarding the degree of caloric restriction) and I would happily acknowledge the same if you refuted my conclusions with actual data instead of your own personal experiences with beer.

No need to be a dick about it.

Posted by: Pheo on September 11, 2007 at 7:44 PM | PERMALINK

I wish public health experts would do a better job of distinguishing between "overweight" as a function of one's position on the population distribution of BMI, and "over-fat", meaning your body composition or %body fat. I am 6'2" and weigh 240 pounds, "overweight" by any BMI standard (in fact, most charts classify me as "obese"), but my bodyfat generally trends under 12%, meaning my "excess" weight is muscle, and I'm decidedly not obese. Crude and oversimplified definitions of "overweight" simply don't paint the whole picture.

Posted by: donbux on September 11, 2007 at 7:58 PM | PERMALINK

If you control for cardiovascular fitness (IF!!!) you will find that rather than making you more likely to die, extra fat makes you more likely to stay alive. Extra fat makes you more likely to survive a heart attack too.

We confound several separable factors in our heads habitually when we think and talk about being "overweight" and it gets even the Harvard guys confused.

Individuals don't have much choice about what they weigh. Bodies will increase appetite and lower body temperature to acheive their goal weights, regardless of what the owners may think about it.

If you look at identical twins separated at birth, who have grown up in different families, maybe even in different countries, their weights differ by only 3 pounds.

Individuals do have choices about whether to dine habitually on fast food or have a salad. They do have a choice about whether and how to exercise. And the consequences of those choices even show up in their bodies and in their health. But it won't change their weight, not in the long term.

So no, weight, in and of itself, has little bearing on health.

Posted by: Doctor Jay on September 11, 2007 at 8:15 PM | PERMALINK

This also doesn't address the really active who can consume more than the recommended 2,000 cal./day and will neither hurt his or her health nor gain weight. And being a cancer survivor (knock on a woody - we're all survivors until we die of something else), I've never read anything about cancer and toxins from burning calories, excessive or otherwise.

JeffII: you need to do more reading (especially as a cancer survivor). There is increasing evidence that excessive metabolic activity (AKA consuming AND burning lots of calories) is dangerous for one's health. Cellular aerobic respiration is what creates free radicals. Eating an ultra high calorie diet and then maintaining one's weight via excessive aerobic exercise essentially amounts to running your body in a similar fashion to always running your car at 90mph. What I'm saying is: those of you have a hard time staying away from the dessert tray and pizza parlor but think you can "make up for it" by burning mega calories on the treadmill might want to rethink your strategy. Our bodies simply didn't evolve to deal with the massively calorie rich diets available cheaply to one and all. And when you treat your body in a manner it's not equipped to deal with from an evolutionary standpoint, bad things happen. I recommend Art De Vany's work on the subject for a quick introduction: http://www.arthurdevany.com/evolutionary_fitness/

Posted by: Jack on September 11, 2007 at 8:30 PM | PERMALINK

Yet another common sense belief, that telling people to eat less and exercise more will result in significant long-term weight loss, has been definitively refuted to the extent that any empirical claim can be.

Here's the hidden side of that -- it's pretty common for overweight people to actually be undereating for what their metabolism actually needs because they've been fed the line that you always have to reduce calories to lose weight. If you're already undereating, and you restrict your calories even more, you won't lose, and you may even see a weird gain, which will frustrate you even more.

With diabetes, they're starting to find that some cases of what they thought were Type II diabetes are actually very slow-acting Type I that doesn't show major effects until middle age. So it could well be that a reasonably normal-weight person who develops diabetes actually has Type I and not Type II.

Posted by: Mnemosyne on September 11, 2007 at 8:37 PM | PERMALINK

There are two points that emerge from a decade-long involvement in health promotion that are relevant to this debate.
1) Absolutely the only figure that counts in public health is the all-causes death rate. It's the only figure that takes all factors, plus or minuis, into account (and it's the only figure that can't be gamed).
2) In Australia, at least - you yanks are a much less good example - average life expectancy has for the last several decades been going up by four months a year. That's not bad; for one thing, it's one-third of the way to living for ever.
There are several further points that would seem to follow from this.
a) The "epidemic of obesity" _can't_ be _that_ bad for us, or it would be significantly cutting in to that rise.
b) A much smaller proportion of what matters for our health is under our own control than we think. Most of what counts is secular trends in our society.

Posted by: chris on September 11, 2007 at 8:42 PM | PERMALINK

I'm no expert.

You make theoretical arguments for why being overweight should be positively correlated with morbidity and mortality. However, the correlation in actual data is negative. I think you can only conclude that your theory is missing something, that there is an unknown cause of mortality and morbidity which is correlated with low weight.

Now in the raw correlation there is certainly something. People with cancer waste away and are very thin. Here the causation is clearly cancer to thin ness.

I think another possible explanation is that eating starchy foods leads to being overweight or obese. If the alternative is veggies, the data are mysterious. However it is possible that low BMI people get more of their calories from meat which is satisfying in low volume (and calories). It is also unhealthy. Someone who lives on potatoes and one a day vitamins plus iron will be fat and healthy compared to someone who lives on steak.

Anyway the facts are facts and if we don't understand them we should work on our theories.

Posted by: Robert Waldmann on September 11, 2007 at 8:47 PM | PERMALINK

Still no expert but I have read the Campos article.
Campos does put a lot of stress on significance. He cites many studies which he says find no difference between people of normal weight and overweight (non obese) people. He means they find a statistically insignificant difference. It is a gross error to consider such a result evidence against the alternative hypothesis that overweight is a source of morbidity and mortality. The correct meta analysis would be to create a precision weighted average of the various estimates of the difference in mortality and test the null that the cross study average difference is zero. Counting failure to reject the null is aweful meta analysis.

I assume that the average difference across studies is lower mortality for the slightly overweight than for people at the lower extreme of the normal range. I note that the pre-existing disease explanation does not work. Also I should of thought of smoking makes you thin and die, but note that Campos claims that exluding smokers doesn't change the pattern.

My guess that meat eaters are thin compared to starch eaters is still in the running. Also I note that alchohol is extra calories above food and moderate alchohol consumption leads to higher HDL cholesterol and lower LDL cholesterol (the rda of alchohol is three glasses of wine a week although even that is bad for your brain). I find it hard to believe that there are many people in the USA who drink too little to maximize their life expectancy, but it's a possibility.

I'd look at another variable of interest like blood cholesterol, or ldl cholesterol (my stories work via cholesterol).

Posted by: Robert Waldmann on September 11, 2007 at 9:04 PM | PERMALINK

Is Inkblot influencing your thinking.?

Posted by: sab on September 11, 2007 at 9:40 PM | PERMALINK

The "epidemic of obesity" _can't_ be _that_ bad for us, or it would be significantly cutting in to that rise.

This is very much an unproven assertion.

1) It's certainly possible (I think overwhelmingly likely) that life expectancy would be increasing faster in rich countries save for the increase in obesity.

2) Life expectancy is not the same as quality of life. Most of would agree that some of the health issues associated with obesity are indeed "bad for us" in that they can seriously undermine our ability to enjoy old age.

Posted by: Jack on September 11, 2007 at 10:29 PM | PERMALINK

Chris is right. K is not obsessing. Period. It's 9-11, testimony on the hill was the last chance of the Dems to grow some cojones and pin the iraq tail on the donkey-in-chief. Iraq isn't just a BFD, it's THE BFD this week and probably for years to come.

This post was a IQ test to see how many readers agree that it's not obsessing if a) this is a political blog and b) it really is a big deal.

And you guys want the Dems to show some backbone?

Posted by: mezon on September 11, 2007 at 11:25 PM | PERMALINK

1) It's certainly possible (I think overwhelmingly likely) that life expectancy would be increasing faster in rich countries save for the increase in obesity. Posted by: Jack

It will be interesting to see where Japan is in a few decades. The diet of kids born in the '70s and '80s is a lot fattier. By 2040 the Japanese may no longer be the longest lived people on Earth. Of course, by 2040 most of Tokyo could be under a couple feet of water or have been nuked by China and/or N. Korea.

Posted by: JeffII on September 11, 2007 at 11:29 PM | PERMALINK

There's some definite problems with this story. This sentence is Example No. 1:

This has led to much chin-scratching over the "paradox" of why "overweight" people often have better average life expectancy and overall health than "normal weight" people.

What does "often" mean? Without percentages stipulated, "often" is just anecdotal.

Posted by: SocraticGadfly on September 12, 2007 at 12:05 AM | PERMALINK

JeffII: you need to do more reading (especially as a cancer survivor).

And you need to read what I've actually written (do I ever mention anything about "ultra high calorie diet"?) and you need to define your terms.

You will not find a study that concludes that eating a balanced 2,000 to 2,500 calories a day (even 3,000 depending on the size and age of the person)coupled with moderate exercise two to three times a week constitutes "excessive metabolic activity." And, again, what and when someone eats plays a huge part in how our cells react to activity and to calorie intake.

Eating an ultra high calorie diet and then maintaining one's weight via excessive aerobic exercise essentially amounts to running your body in a similar fashion to always running your car at 90mph.

Good analogy. Except that we weren't talking about 20-year old college football players during summer two-a-days. This discussion began with the arbitrary number of 3,000 calories thrown out by Pheo as if this was the bench mark for over consumption, again, with no reference to age, gender, stature, occupation, "lifestyle" or, and this can't be stressed enough, what someone eats.

What I'm saying is: those of you have a hard time staying away from the dessert tray and pizza parlor but think you can "make up for it" by burning mega calories on the treadmill might want to rethink your strategy.Posted by: Jack

Duh. But not even people in good shape can stay on a treadmill long enough to burn more than 300-500 calories (I burn about 300 on an elliptical trainer in 20 minutes and I'm winded and wringing wet when done). So the idea that going into calorie overload one night by eating three slices of pizza and drinking a soda or beer or two to wash it down (2,000-4,000 cal.), and can then burn it all off then next day at the gym is asinine, and no where do I state this. You won't make a dent in the calories you consumed the night before unless you starved yourself for the next couple of days. And even then, your body may begin to consume muscle rather than stored fat because you need a certain chemistry to achieve effect the latter.

And as far as your link, back at you.

http://www.arthurdevany.com/2007/08/cellular_autoph.html

And again.

http://www.arthurdevany.com/2007/08/a_veganaerobici.html

And finally.

http://www.arthurdevany.com/2007/07/ill_run_it_off.html

Posted by: JeffII on September 12, 2007 at 12:15 AM | PERMALINK

but your reader who said you were obsessing about Iraq is an idiot. It's *OKAY* to obsess about Iraq, because it's a big fucking deal.

I am said reader, and that's not actually what I said to Kevin; he was making a flippant summary of my comment. I didn't use the word obsess, and in any case I'm quite pleased with the writing Kevin's done on Iraq. I merely observed to him that his coverage of Iraq had been so heavy the last few days as to completely exclude any mention of any other issue for nearly a week. It was the exclusion I took (mild) exception to, not the focus Iraq, with which I am fine.

Kevin's Iraq writing is fantastic, but I also like to see Kevin's opinions on other issues as well.

Iraq isn't just a BFD, it's THE BFD this week and probably for years to come.

Indeed. And yet the GWB administration is notorious for using the news cycle's monomaniacal focus on a single issue to get away with murder in some other milieu. I wonder what they *else* are doing to the middle class right now while we think of nothing but Iraq.

I fear the long-term effects of Bush's plutocratic agenda as much as I do the effects of Iraq. Which, since Kevin is one of the few bloggers who seem actually aware of that agenda, is why I thought it surprising that he had zero posts about non-iraq in the last few pages.

I wasn't asking him *not* to obsess about Iraq, nor calling it obsession, nor implying it was a bad thing...

Posted by: Idahoev on September 12, 2007 at 12:21 AM | PERMALINK

It should be remembered that BMI is nothing more than a guideline. It is not and never was intended to be a be-all and end-all of body health.

Posted by: raj on September 12, 2007 at 12:48 AM | PERMALINK

"But not even people in good shape can stay on a treadmill long enough to burn more than 300-500 calories (I burn about 300 on an elliptical trainer in 20 minutes and I'm winded and wringing wet when done). So the idea that going into calorie overload one night by eating three slices of pizza and drinking a soda or beer or two to wash it down (2,000-4,000 cal.)"

I'll actually take issue with this. First, three slices of pizza and a beer/soda are around 1100 calories, assuming normal-sized slices of non-Chicago-style pizza.

Second, you apparently don't know many distance runners. Your average 150 pound male will burn about 120 calories/mile running at a brisk (say sub-8:00) pace. So I just burned around 750 calories on my run (about to hit the shower), maybe a little more because I was going around 7:00 pace. And I'm not even in racing shape now. When I am, my normal run will be closer to 10 miles than 6. And that doesn't count the long runs (usually 4 or 5 at 20+, spread out over the three months before a marathon). I'll actually try to calorie overload before those. If you don't, you can lose a lot of weight quickly, and that's not healthy.

Posted by: Joe on September 12, 2007 at 10:05 AM | PERMALINK

Nice links, JeffII. I link to JAMA and you link to a blog from an emeritus professor of economics.

Posted by: Pheo on September 12, 2007 at 11:44 AM | PERMALINK

JeffII: "...some people will have a predisposition to poor insulin production or high blood pressure or high 'bad' cholesterol. But none of these things have to do with being fat. Juvenile diabetics are usually look anorexic."

That last part is pretty misleading, at least to people who don't already know the difference between Type I and Type II diabetes.

In Type I, which is (usually) juvenile onset, the pancreas does not secrete enough insulin; kids with Type I diabetes stay thin because, without insulin, their body can't do anything with sugar - not even store it as fat. Type II diabetes is insulin resistance - a normal level of insulin is no longer sufficient to get the body to metabolize sugar. Many things can predispose you to develop insulin resistance; it's not clear whether obesity is more of a cause or an effect, but obesity and insulin resistance are highly correlated - that's not controversial at all - so it's not true that Type II DM has "nothing to do with being fat".

Posted by: Hob on September 12, 2007 at 3:51 PM | PERMALINK




 

 

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