Welcome to my chapter-by-chapter review of Rethinking Thin, the 2007 book by science writer Gina Kolata. Rethinking Thin was written after the conclusion of a large study comparing a low-carb diet to a reduced-calorie diet. Tonight, I'll be continuing with the "Five Months" interlude between Chapters 5 and 6, followed by a review of Chapter 6 itself.
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Rethinking Thin, by Gina Kolata
The story so far:
In chapter one, Kolata introduced Mr. Carmen Pirollo, one of the participants in the large diet comparison study. She then discussed the two diets - the low-carb Atkins regimen, and the low-calorie LEARN lifestyle program. She followed that with an exploration of the phen-fen (a combination of phentermine and fenfluramine) fad of the 1990s, and finished the chapter by detailing Mr. Pirollo's experiences with phen-fen and his other diet successes and failures.
In chapter two, she showed how everything old is new again when it comes to diets. She started with the 19th-century origins of low-carb diets with Brillat-Savarin and Banting, and low-protein regimens from Sylvester Graham and Horace Fletcher. She also discussed the history of calorie counts on restaurant menus, and an early 20th-century weight-loss contest (very much like today's The Biggest Loser phenomenon, complete with post-contest weight regain).
In chapter three, Kolata looked at societal attitudes toward obesity. After looking at modern attitudes toward obesity, she traced the beginnings of the modern attitudes about obesity to the Gibson Girl and flapper eras of the early 20th century. Three then-new inventions helped democratize worrying about one's weight - the inexpensive bathroom scale, the inexpensive full-length mirror, and inexpensive photographic reproduction in magazines.
In chapter four, Kolata introduced Albert J. "Mickey" Stunkard, an obesity researcher who founded the Center for Weight and Eating Disorders at the University of Pennsylvania, which is the institute performing the long-term study (comparing the low-carb Atkins diet with a more normal low-calorie diet) that is followed throughout Kolata's book. Stunkard became an obesity researcher after encountering puzzling psychological behavior in obese people who were in psychotherapy. His research, and that of others, has shown that obese people aren't obese because they're crazy - that is, there are no psychological disorders common to fat people that are not found in comparable numbers in people of "normal" weight.
In chapter five, she continued with a look at obesity research in the late 20th century. She started with a look at the WWII research by Ancel Keys (whose post-war research inspired the Mediterranean Diet) on starvation. Keys found that starving men developed an obsessive interest in food and eating. Kolata next looked at research performed by Jules Hirsch, who found that severely obese (more than 100 pounds overweight) dieters also tended to develop an obsessive interest in eating. Hirsch also found that those dieters tended to put the weight back on after the research program ended.
Research by Ethan Sims showed that normal-weight people who gained weight on purpose increased their metabolism as they gained, and had no problems losing the weight after the end of the research. Kolata looked at later research from Mickey Stunkard, which research indicated that obesity is more a matter of heredity than environment. Toward the end of chapter five, Kolata showed that studies done by Claude Bouchard challenge the idea that "a calorie is a calorie" while providing more evidence of weight "set-points."
Interlude: Five Months
Two months after the previous interlude, Kolata focuses on the low-calorie dieters once again. The facilitators of the Penn diet study ask the dieters what social cues lead to overeating. For Graziella Mann, it's her mother and next-door neighbor. For Jerry Gordon, it's poker night with his buddies, where he's "in the closet" about his participation in the Penn study -- "Somehow, that's not manly," he says. A common challenge is the fact that food is not something that can be given up altogether, like smoking, drugs, or even sex. After all, you have to eat to live.
An unnamed member of the low-calorie group talks about how difficult he'd found it to give up foods when the goal is to lose weight, compared to how easy it was for him to give up foods that were forbidden by his religion. This man decided to keep kosher as an adult - in fact, he made the decision when he and his wife were on their honeymoon, and had kept that commitment for over seventeen years (as of the date of the Penn study, at least). He says, "The only thing I can come up with is that the reasons I want to lose weight--I want to feel better, to look slimmer, to look better--are not powerful enough" (compared to following his religion).
Chapter 6: Insatiable, Voracious Appetites
In chapter 6, Kolata begins by asserting
...for some people, at least in some circumstances, something is going on in the brain that compels them to eat...Wanting to eat less works for only so long.
What is it about "some people" that makes them eat more? Kolata examines the case of "R.D.", an Austrian teenage boy who was taken to the office of doctor Alfred Froehlich in 1901. R.D. had a number of medical issues, including headaches, blindness in one eye, underdeveloped genitals - and severe obesity. Dr. Froehlich diagnosed a pituitary tumor, and operated on R.D. to remove it. The result? There was a "considerable improvement in the general condition," according to Froehlich. Based on this, it was thought for a while that pituitary problems cause obesity.
This misconception wasn't resolved until the 1940s, when scientists created brain lesions in the hypothalamus in rats. The hypothalamus is connected to the pituitary, and is in an area of the brain that would have been compressed by R.D.'s tumor, which is why the boy's symptoms were relieved by removal of the tumor. The effects of the artificial lesions in the brains of the rats were more dramatic than R.D.'s pre-operative condition. As soon as the rats had awakened from the anesthesia, they began eating - and eating, and eating. Three rats inhaled food into their lungs when they began gorging themselves before the anesthesia had fully worn off. Unsurprisingly, the rats that survived the immediate post-op period became obese as they continued to gorge themselves over the next weeks and months.
This evidence that the hypothalamus was involved in appetite control was further supported by examples from human medicine. Kolata mentions a couple of cases, including one of a teenager who suffered a brain injury when hit by a car and gained a couple of hundred pounds "literally in weeks," according to the researcher.
After looking at how brain injuries can affect appetite, Kolata turns her attention to genetic causes of overeating. She writes about two strains of mutant lab mice - ob (for "obese") and db (for "diabetic"). The ob mice were severely obese, weighing three or four times as much as a normal mouse. The db mice were "merely" twice as heavy as normal mice, but their insulin levels were very high, much like human diabetics.
Researcher Douglas Coleman worked with the db mice while working on diabetes. He operated on pairs of mice, suturing a db mouse to a normal mouse to create artificial conjoined fraternal twins. He found to his surprise that the normal mice died of starvation - after they woke from the operation, the db mice continued their usual eating habits, but the normal mice in the pairs never ate again and starved to death.
Coleman wondered what would happen if he paired normal mice with ob rodents. In this case, the normal mice continued their normal eating habits, but the ob mice ate less than before, and slimmed down to the size of a normal mouse!
Coleman postulated the existence of a satiety factor, a chemical that tells the organism to stop eating when it's had enough. In Coleman's second round of experiments, the ob mice received this satiety factor from the bloodstream of their normal conjoined twin, and it caused the ob mice to respond normally for the first time in their lives. OTOH, in his original experiments, the db mice were flooding their twins' bloodstreams with this satiety factor, causing the normal mice to stop eating. That is, the db mice were making the satiety factor, but not responding to it themselves, while the ob mice didn't make the satiety factor.
Of course, it's easy enough to find a genetic cause for obesity. It just requires painstaking microsurgery on pairs of fragile lab animals. Identifying that genetic factor, however... In fact, Coleman retired in 1991 without finding out what the chemical signal was or what gene controlled it. The search was taken up by other researchers, including Jeffrey Friedman.
Kolata has quoted Friedman in earlier chapters of Rethinking Thin, but it's only now in chapter six that she first refers to his actual work (rather than his opinions). Friedman and fellow researcher Bruce Schneider looked at CCK, a protein produced in the gut after eating. Many researchers thought that CCK could be the unknown satiety factor, but Schneider showed that ob mice made as much CCK as normal mice.
Before continuing with the search for the elusive satiety factor, Kolata asks "Is it genetics or environment?" once again. On the "genetics" side ("Obesity is caused by genetic factors outside our conscious control"), Kolata pits the tag team of Friedman and Schneider. On the other side ("We can control our weight by controlling our environment"), Kolata introduces researchers Paul Rozin and Brian Wansink.
Of course, Wansink is a familiar name to us in WHEE, but Rozin's name is a new one. Rozin has made a name for himself in studying taste and distaste - or rather, disgust. In other writings, he has compared Americans attitudes toward food to those in other countries, especially France. He argues that American attitudes to food cause us to see food as more a problem than a source of pleasure. However, in Rethinking Thin, it's Rozin's experiments with serving sizes that interest Kolata. For example, residents in an apartment building were provided a tray of large soft pretzels in the lobby on a "help yourself" basis. Residents ate 40 pretzels per day on average. Rozin then cut the pretzels in half, and found that the consumption dropped to around 30 pretzels per day.
In the question over whether our increasing waistlines are being driven by our genes or by our environment, Kolata argues that genetics plays the most important role. She says that the studies showing environmental influence
...assumed two things. First big portions of food are making people fat. Second, eating more food at one meal, or in one snack, or at one movie, has no effect on what you eat the rest of the day...Does that happen, or do people compensate over the day, or the week, or the month?
After casting aspersions on the utility of the research of Rozin and Wansink, Kolata returns to the story of Friedman's search for the unknown satiety factor. Over the next seven pages, she takes us into Friedman's lab to give us a good idea of the difficulty of identifying the gene responsible and the chemical substance that the gene regulates. She ends chapter six with Friedman's triumphant discovery of the satiety factor, a hormone which he names "leptin."
Some comments (Ed)
While I think Rethinking Thin is a great piece of science writing, I don't agree with Kolata's apparent conclusion that America's overweight and obese are helpless victims of their genetics. If this were the case, our obesity rates would be more or less stable - but they're not. Our weights have risen, particularly over the past few decades. At the same time, our foods have become richer (that is, more calorie-dense), and the portions have become larger. Concidence? I think not...
Kolata asks, "Do people compensate?" Well, as we've seen in previous months here at WHEE, adults do NOT compensate. In fact, according to research cited by David Kessler,compensation is pretty much found in young children only. Given that, the idea of re-engineering one's environment to limit the calories in snacks and meals seems like an eminently reasonable thing to try. And my experience, and that of my partner in
crime, er, book reviewing, bears that out.
I lost more than 20 pounds (from over 230 down to around 205) after reading Brian Wansink's book and consciously eating slower, limiting the amounts of calorie-dense foods, and eating more servings of fruits and vegetables. After losing another 20 pounds with a combination of low-carb dieting and exercise, I lost the last 30 pounds by rigorous calorie counting and continued exercise. Can I keep this up for the rest of my life? Well, we'll see when I get there.
In the "Five Months" Interlude summarized above, the man who found himself able to avoid non-kosher foods but not the off-diet ones asked plaintively, "How do you get the reasons why you want to lose weight to be important enough to maintain that self-control forever?" I can definitely sympathize with his feelings. When I was a young man, the idea of having to count calories to lose weight for the rest of my life seemed impossibly strict. As I've grown older, though, I've started to think differently.
For one thing, maintaining that kind of discipline to control weight is hard - but compared to what? Compared to being able to eat whatever I wanted and not gain weight, as I could do when I was 23, the calorie-counting regimen does seem a heavy cross to bear. However, if the alternative is counting grams of carbohydrates and calculating the amounts of insulin I need to inject, counting calories doesn't seem quite so bad. "Worse things happen at sea," as my British in-laws might say.
For another thing, counting calories and limiting portion sizes are stressful - but they get easier with time, like anything else. Do you remember how stressful driving was, in the first weeks and months after you got your license? Remember having to consciously remind yourself to signal your lane change, check your rearview and side mirrors, etc? Now, after a few years of driving, your daily commute is pretty much out of conscious awareness, unless something out of the ordinary happens.
All that being said, it has to be added that genetics and physiology do play a big role in weight control. For some, like R.D. (the Austrian boy with the pituitary tumor), they're the dominant factors. Genetics limits the bounds of our weight range - but that range is much larger, and much more amenable to changes in our environment, than Friedman or Kolata seem to think, IMO.
Scheduled WHEE diaries:
Thur AM - creekobear
Thur PM - hold tight
Friday AM - WHEE Open
Friday PM - Wee Mama (weekly diary)
Sat AM - WHEE Open
Sat PM - Edward Spurlock (Wansink, Ch. 5)
Sun AM - WHEE Open
Sun PM - WHEE Open
Mon AM - NC Dem
Mon PM - WHEE Open
Tues AM - WHEE Open
Tues PM - WHEE Open
Weds AM - WHEE Open
Weds PM - Edward Spurlock (Kolata, Ch. 7)