Wednesday, December 19, 2007

Rethinking Thin, by Gina Kolata

Why are some people fat? Why do they stay fat or regain weight after losing it?

In Rethinking Thin, Kolata doesn't have the absolute answer to those questions but she takes us a lot farther than most. We've all heard various "facts" about obesity and dieting over the years, so often that many of us don't question their truth. Kolata asks different questions and gets surprising answers from controlled studies, which she summarizes here. Her investigation is hung on a frame: the story of real people who are subjects in a two-year study that compares two different types of diets: Atkins and a standard low-fat alternative.

Do you want to know which diet comes out ahead? That's the wrong question and Kolata knows it. The fact that huge research centers spend all their time on this type study is one indication of how the so-called science of weight loss has failed us.

When I was working in various offices my co-workers invariably included many who wanted to lose weight. These people kept looking for the right diet, and those who were succeeding in losing weight would dispense advice about how they did it. During part of that time I had been "successful" and was managing to maintain a healthy weight, so people would ask me for advice too. One thing I knew: it is possible to lose weight many different ways. The real problem is keeping it off. And on that front I had no magic answers. I only said that for now I was managing, I was keeping on top of it, my mind was in the right place, but I had no idea why or whether that would remain so. I have since "slid". I have regained much of that weight, and it happened much as a balloon once filled with air more easily takes air the second time.

A few interesting facts:

* when naturally thin people force themselves to gain weight (or gain weight because of some unusual situation) and fat people lose weight and both groups weigh the same (lower for the fat, higher for the thin) it takes fewer calories for the fat people to maintain the same weight as the thin.

* normal people who are forced to lose weight (like in a concentration camp or in a controlled study in the military) they become obsessed with food. They dream of recipes, they buy kitchen equipment. When they get freed to eat as they like again they eat enormous amounts, much more than they would have if they had never dieted.

* hunger is a drive that is far harder to resist for a fat person than a thin one. It is totally distracting and almost impossible to resist.

* there does appear to be a "set point" for most of us. Usually we waver somewhere within 30 pounds of that set point, regardless of how we eat. Thin people who say they maintain their weight with constant vigilance, that if they gave in to their urges they would become huge, are actually not correct; they would gain maybe ten pounds, maybe a bit more, and then stop, and it would not be difficult to go back to where they were. I have long noticed that the diet companies are clever to focus on those who are naturally thin who might have gained five pounds over a holiday - these folks won't have a problem losing the weight or keeping it off.

* some people are born without a hormone - I think it's a hormone - that regulates food intake. They are always hungry and gain weight rapidly and will eat anything. There are examples in the book of some who have been helped by regular injections of this chemical, and the help has been amazing. There was an episode on House recently that featured a young woman who had always been fat. House actually found a medical condition that explained it, and when corrected she lost that weight. There are, in other words, some medical conditions that do cause people to gain weight.

* fat people really do have more fat cells than thin people. When we fatties lose weight we do not lose fat cells. Instead, they become starved, wanting to be filled again.

* when sodas were removed and healthier foods added to cafeterias and increased exercise required in some studied schools, these changes made no statistical difference in body mass of the students.

* here's a kicker: people who are very thin or very fat have a mortality rate higher than the normal. Those who are overweight but not in the "morbidly obese" category actually have the edge on living longer. Fat people do experience medical conditions, like diabetes or arthritis, that are more debilitating than thin people, but statistically these diseases do not affect longevity. In other words, obesity is not as dangerous as you thought.

Kolata suggests that perhaps we are all born with a certain possible top weight. Because of the food available to us, many of us have reached higher weights than ever before. She concludes that it takes an enormous amount of so-called willpower to stay on a rigorous diet and exercise program for a long period, and that it takes a great deal more will for a fattie than a thinny, given that it takes fewer calories to maintain the same level in the fattie and that hunger is a more powerful drive in the fattie.

I read somewhere else that it is possible to change the set point, through regular exercise. I managed to keep weight off and to exercise regularly for a long time but that did not save me ultimately. When I was forced to rest because of an injury I seemed to have a brief "grace period", when I could maintain my weight, but then the pounds started creeping back on again. And now that I am fat again and faced with debilitating arthritis I am finding it much more difficult to get in enough exercise to cause a reduction in pounds.

This book is important for sorting out what's true and what isn't, what we know and what we don't. It is a quick read, interesting and informative, and perhaps most importantly it skewers the weight-loss industry. The folks who are getting rich off our heavy backs, who find it in their best interest not to tell us the truth.

I am hoping that further research into the areas that matter will take place and that someone like Kolata will let us know about it.

book rating: 4.5 out of 5

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