The New York Times excerpts Gina Kolata’s new book, Rethinking Thin: The New Science of Weight Loss — and the Myths and Realities of Dieting reviews early human experiments on weight loss and gain. (free registration required)
http://www.nytimes.com/2007/05/08/health/08fat.html
http://www.nytimes.com/2007/05/08/health/08fat.html
and
A 1959 experiment on very low calorie dieting found that "fat people who lost large amounts of weight might look like someone who was never fat, but they were very different. In fact, by every metabolic measurement, they seemed like people who were starving....The Rockefeller subjects also had a psychiatric syndrome, called semi-starvation neurosis, which had been noticed before in people of normal weight who had been starved. They dreamed of food, they fantasized about food or about breaking their diet. They were anxious and depressed; some had thoughts of suicide. They secreted food in their rooms. And they binged."
Dr. Ethan Sims at the University of Vermont...asked what would happen if thin people who had never had a weight problem deliberately got fat.
His subjects were prisoners at a nearby state prison who volunteered to gain weight. With great difficulty, they succeeded, increasing their weight by 20 percent to 25 percent. But it took them four to six months, eating as much as they could every day. Some consumed 10,000 calories a day, an amount so incredible that it would be hard to believe, were it not for the fact that there were attendants present at each meal who dutifully recorded everything the men ate.
Once the men were fat, their metabolisms increased by 50 percent. They needed more than 2,700 calories per square meter of their body surface to stay fat but needed just 1,800 calories per square meter to maintain their normal weight.
When the study ended, the prisoners had no trouble losing weight. Within months, they were back to normal and effortlessly stayed there.
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Date: 8 May 2007 04:38 pm (UTC)Good to see people are continuing to spread the word.
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Date: 8 May 2007 04:47 pm (UTC)no subject
Date: 8 May 2007 04:49 pm (UTC)no subject
Date: 8 May 2007 05:16 pm (UTC)no subject
Date: 8 May 2007 05:18 pm (UTC)It's pretty shocking to me that it's taken this long to do twin studies about weight.
99% of what is said about obesity, nutrition, and exercise is total unfounded bull. (You're in the 1% by the way.)
Thanks!
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Date: 8 May 2007 06:10 pm (UTC)no subject
Date: 8 May 2007 06:49 pm (UTC)no subject
Date: 8 May 2007 08:41 pm (UTC)no subject
Date: 8 May 2007 09:05 pm (UTC)Those were done in 1990...and have been vigorously ignored ever since.
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Date: 8 May 2007 09:14 pm (UTC)However, I would, for once, like to see an article that challenges standard beliefs about weight, in a mainstream paper, that doesn't have to do some kind of ritual backpedaling at the end. Even this article has this as its final two sentences:WHY must we resist it??? Despite all this evidence, they're still managing to say that we have to lose weight. Why?
I have two other questions about this article.
One is about the 1959 study. After the subjects had been dieting and had lost, on average, 100 pounds each, the scientists found that they all showed both physical and psychological signs of starvation. However, the article had stated earlier that these subjects were on 600 calories a day. Of course they were starving! I'm just curious what their systems would have shown if they had been only slightly calorie-deprived - enough to lose weight, but very, very slowly. (I realize this would have been very unwieldy for a study.) Have studies been done on this?
My other question is, why are Americans, on average, fatter than people in most other places in the world? I know there are homogeneous populations some places, where the people tend to be fat (eg, indigenous Samoans), which certainly points to genetics. But in the US we have a very diverse population, so the idea that we have some kind of special "American genes" makes no sense to me. Environment must play some role.
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Date: 8 May 2007 10:04 pm (UTC)As for studies on slow weight loss, I don't know if anything's been done rigorously; of course there is plenty of evidence that eventually a fat person will stop losing weight on some given level of calorie intake (the famous diet plateau) and in some cases will start gaining again.
As for Americans being fatter than other people, I know I've heard that parroted various places, but is it really true? I've never seen it accompanied by convincing data.
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Date: 8 May 2007 10:16 pm (UTC)Good point. I'm thinking of comments I've heard from Europeans and Asians over the years. Of course, that's only anecdotal "evidence", and I can't offer anything more substantial than that.
I guess a good question to ask is, who is saying this? And what agenda do they have? I'm not convinced that everyone who says it is just parroting - many people might actually experience Americans as being fatter than people from other countries. That doesn't make it a fact, but if that perception is actually out there, then where is it coming from?
I tend toward "a combination of nature and nurture" as the most reasonable explanation for many phenomena, and the human body is certainly complex enough that there is room for more than one influence.
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Date: 8 May 2007 11:33 pm (UTC)glad you asked....I don't like people slinging the word "must" like that.
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Date: 9 May 2007 08:27 am (UTC)But the data is reasonably sound showing year to year changes within the U.S., because the CDC has been tracking BMI for about 40 or 50 years, using, AFAIK, more or less the same methodology across the decades. And there you see BMI increasing.
Unfortunately everybody points to that average increase in weight as evidence that it's "all environment." But that's bogus logic. The increase is only equivalent to about 7 lbs on average per person during the so-called "obesity epidemic". That's well within the "comfortable range" which people can gain or lose without major metabolic and appetite changes kicking in according to these studies.
And more importantly that increase of 7 lb is just a small nudge up of a bell curve that spans hundreds of pounds. So it's like saying a 5 point average increase in IQ means that all intelligence is purely environmental. That's ridiculous. IQ varies by 100 points or more, that you may or may not be able to nudge it in one direction or another doesn't mean it's infinitely malleable. The bell curve for height has also been nudged up over the past century. But everybody considers the environmental impact to be small compared to the genetic influence.
Most graphs that chart the "obesity epidemic" make the population changes look a lot more dramatic than they are, because instead of just comparing average or median BMI's, they use "percent obese." This creates a threshold effect, since the threshold for being labelled "obese" has always been very close to the peak of the bell curve. In other words a small change in BMI nudges a large fraction of the population from "overweight" to "obese" and you get a 5 or 10 lb average weight change increasing the number of obese by huge amounts (I think it's by 100% or so currently - something like that).
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Date: 9 May 2007 11:31 am (UTC)no subject
Date: 9 May 2007 06:19 pm (UTC)And, I've said this a lot because many people seem to forget it (probably not people reading this, because most size activists have been paying attention to this), but 9 years ago, the national threshold for "obesity" was lowered, allowing millions of people who were merely "overweight" to become "obese" overnight. Unless that change is adjusted for, it just looks like there was a sudden jump in fat people over the past decade.
It would be interesting to get real data on weight statistics from other countries, particularly from countries that are similar to the US - ie, Westernized, industrial, and wealthy countries - that would have similar conditions to ours, so comparisons would make some sense.
The bell curve for height has also been nudged up over the past century. But everybody considers the environmental impact to be small compared to the genetic influence.
Actually, 100 years would have no impact whatsoever on the overall genetic change of a population (unless there was some sort of cataclysm, weeding out all but a few members of the population). So the fact that we're taller than we were 100 years ago actually is due to environment - specifically, changes in our diet. (More meat protein, I think.)
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Date: 9 May 2007 06:38 pm (UTC)no subject
Date: 9 May 2007 08:40 pm (UTC)We know that good nutrition, immunizations, and so on result in taller humans. Why not heavier ones?
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Date: 9 May 2007 08:49 pm (UTC)Not to mention that the "obese" BMI was moved from >32 to >30 in 2000. On 5'9" me, a change of 7lbs is a change in 1.1 on my BMI.
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Date: 9 May 2007 09:46 pm (UTC)