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 "Three Months" interlude between Chapters 4 and 5, followed by a review of Chapter 5 itself.
If you've been following this review of Rethinking Thin in WHEE, you're probably saying to yourself, "About time!" I've taken a couple of unplanned weeks off from this weekly diary review, to the point where I was taken off the WHEE schedule. But I'm back, tanned, rested, and ready to continue with the book.
WHEE (Weight, Health, Eating and Exercise) is a community support diary for Kossacks who are currently or planning to start losing, gaining or maintaining their weight through diet and exercise or fitness. Any supportive comments, suggestions or positive distractions are appreciated. If you are working on your weight or fitness, please -- join us! You can also click the WHEE tag to view all diary posts.
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.
Interlude: Three Months
In the previous Interludes and chapters, Kolata introduced us to a number of the dieters in the low-carb and low-calorie portions of the study. In the "Three Months" interlude, she continues with the story of four of these dieters. Carmen Pirollo is in the low-carb group. He has lost 24 pounds from his 237-pound starting weight, and his friends are starting to compliment him on his noticeable weight loss. Jerry Gordon and Ron Krauss, two men in the low-calorie group, started at the same weight as Mr. Pirollo, and have both lost 23 pounds.
The researchers have been telling the dieters that they should be happy to finish the two-year study with a 10 percent weight loss, but the three men hope to lose more than that - after all, they've already lost 10 percent of their body weight, so there seems to be no reason why they shouldn't be able to lose more.
The "odd man out" is Graziella Mann, a woman in the low-calorie group. Unlike the three men, she has fallen short of a 10% loss - she's only lost 14 pounds of her starting 223, her weight has been stable for the past month, and the calorie-counting is becoming tedious. Like Ron Krauss, she's starting to worry that the reason the researchers make such a point of being happy with a 10% weight loss is that the researchers don't expect any of the dieters to be a success. While the men are feeling successful with their weight loss, Graziella is beginning to feel that she has failed, even though her average weight loss is more than a pound per week.
Chapter Five: A Drive To Eat
Kolata begins by discussing a study by Ancel Keys that took place during World War II. Keys became famous after the war for the Seven Countries Study, which began in 1958 and found that people whose diets favored unsaturated fats like olive oil had much lower rates of heart disease than those who ate more saturated fats from meat and dairy. This study was the original inspiration for the Mediterranean Diet and the impetus for the idea that margarine (made from unsaturated fats that were hydrogenated to make them solid at room temperature) was a healthier spread than butter.
In his WWII experiment, Keys started with 36 healthy young men of normal weight (they were conscientious objectors who volunteered for medical research in lieu of military service). Their usual diets and activity levels were studied for three months. After that, their calorie intake was restricted to about half their normal amount, and they were required to exercise, walking over three miles per day. Over the six months of this regimen, the men lost 25 percent of their weight. For the next three months, they were fed enough to regain most or all of their weight, and for the remaining nine months of the study, they were allowed to eat as they pleased to see while the researchers continued monitoring.
Keys found that during the "starvation" period, the men grew obsessively interested in food, cooking, food preparation, and agriculture. Some who had shown no previous interest in cooking began reading recipes and cookbooks. Some even began collecting cooking implements. Their psychology was also affected - while they were losing weight, they lost interest in sex and dating. They became prey to "bouts of depression, irritability, and mood swings."
The physiological changes during the weight-loss phase were also alarming - their metabolic rates slowed to 40 percent (!) of their pre-study levels. Their heart rates slowed and their body temperatures dropped. The mens' appetites during the re-feeding were almost as alarming. One man would eat more than 5,000 calories during meals, and start snacking an hour later. Other men found themselves eating 8,000 to 10,000 calories per day!
Kolata left the discussion of this study at this point, but noted that shortly afterward, men who had been prisoners of war in WWII and had been starved during their captivity reported the same obsession with food and cooking seen in Keys' study participants. Kolata quotes one former POW as saying, "Food--that's the only thing that interested them. Most of the time, you get GIs together and they start talking about girls and ass and screwing, but the only thing they were doing was taking recipes down."
Kolata next examines studies performed by Jules Hirsch at Rockefeller University. Hirsch was trying to find out whether vegetarian diets helped prevent heart disease. Along the way, he discovered that the type of fat stored in the body's fat cells is an indication of the type of fat in the diet - for example, study subjects eating diets high in corn oil had fat cells containing high levels of linoleic acid, an unsaturated fat found in corn oil. More to the point of the study, he found that heart disease rates had risen during a time when Americans were eating less saturated fat from meat and more unsaturated fats from plants, which ran counter to the conclusions drawn from Ancel Keys' Seven Countries Study.
While trying to determine whether obese people ate more animal fats than the non-obese (they didn't, at least in Hirsch's study), Hirsch discovered that the fat cells found in the obese tended to be both much larger and more numerous than those found in the non-obese. He began wondering what would happen if obese people lost weight - would their fat cells just shrink, or would their numbers decrease as well? He recruited four morbidly obese people and fed them a maintenance diet for four weeks while studying their calorie intake and metabolic rates, followed by four or five months of a 600-calorie per day liquid diet. All four subjects lost weight, 100 pounds on average. Unfortunately, they all gained it right back!
Hirsch repeated the experiment a couple of times, and got the same result - almost all the obese people who lost a lot of weight gained it back after the end of the experiment. And that's not all - Hirsch also found that the obese people who lost a lot of weight showed many of the symptoms that Ancel Keys reported in the normal-weight volunteers on his earlier starvation diet. For example, Hirsch's subjects developed an obsessive interest in food and cooking. They also shared some of the same metabolic changes - for example, their metabolism (expressed as calories burned per body surface area) dropped by 24 percent on average.
Kolata next turns her attention to research performed by Ethan Sims at the University of Vermont. He wondered what would happen if people tried to gain weight on purpose, and recruited a number of student volunteers to overeat. The experiement was something of a failure, however, as most of the volunteers were unable to gain much weight. Thinking that perhaps the subjects responded by increasing their physical activity, burning off the added calories, Sims then recruited prisoners for a follow-up study. The experiments succeeded, after a fashion - the prisoners did gain weight, but far less weight than would be expected.
Sims found that the prisoners who went from a normal weight to overweight also increased their metabolism by about 50% over their previous rate. Sims then recruited a number of morbidly obese subjects who dieted down to the same level of obesity and overweight as the first subjects. As one might expect from Hirsch's and Keys' experiments, these latter subjects had their metabolic rates fall below normal. In fact, although the two groups had similar weights, the formerly-normal prisoners needed twice as many calories to maintain their levels of overweight and obesity. When the experiment ended, the formerly-normal prisoners had no problems returning to their previous weights. This experiment was one of the bases for the concept of weight "set-point," the idea that we all have a "natural" weight that we tend to return to.
At this point, Mickey Stunkard makes a reappearance. In the late 1970s, Stunkard wondered how much influence heredity had on overweight and obesity. He found that Danish researchers had been tracking height and weight of all the children who'd been adopted from 1927 to 1947, and the database included the names of all the biological parents as well as the adoptive parents. It took Stunkard five years to get access to the data, and another three years to write the report (which was published in the New England Journal of Medicine in 1986). He surveyed all the parents and siblings that he was able to track down, and found that the weights of the adoptees was influenced almost totally by heredity, not by their adoptive environment. He followed this study of the Danish data with a 1990 study (also published in the NEJM) of Swedish twins. He found that identical twins tended to have identical rates of overweight and obesity, regardless of whether the twins had been reared together or apart. The strong relationship between heredity and obesity was born out to a lesser extent in fraternal twins, who share fewer genes than identical twins. In the latter paper, Stunkard and his fellow researchers concluded that the nature/nurture influence is about 70%/30% for overweight and obesity. Perhaps the only surprise in Stunkard's studies is that one has as much as a 30% chance of losing weight and keeping it off!
Kolata then takes a look at the research of Louisiana State University researcher Claude Bouchard, whose study appeared in the same edition of the NEJM as Stunkard's paper. Like Sims, Bouchard recruited normal-weight men and attempted to make them gain weight. However, rather than simply attempting to make normal-weight people obese, Bouchard overfed all the men by the same amount, 1000 additional calories per day. Over the course of the study, this should have added 23.3 pounds to each man. However, Bouchard's subjects gained between 9.5 and 29 pounds. He found that those who gained the least weight gained more muscle mass than the others. However, according to Kolata, when the study ended, "...all the young men effortlessly returned to their original weights, just like the subjects in Sims's studies of overfeeding." [emphasis mine - Ed] Kolata goes on to point out that this study is more evidence in support of weight "set-points."
In trying to lose weight, the obese are fighting a difficult battle. It is a battle against biology, a battle that only the intrepid take on and one in which only a few prevail.
Some comments (Ed)
As I noted earlier, I've put off reviewing this chapter for a couple of weeks. I had a couple of things come up, including another thing that I procrastinated about last week. However, I think there may have been something else going on.
Of course, looking at the size of this diary, and comparing it with my review of Chapter Four, it's obvious that there's a LOT more information in this chapter than the previous one. The studies that Kolata reviews span more than fifty years and several researchers, including some of the biggest of the Big Giant Heads of obesity research. So I could see it was going to be several hours of work.
Perhaps it was just that I didn't like the conclusions of these studies, and found myself unable to proceed until I found something to criticize. It's definitely the case that I resist the idea that if one has lost weight, one is doomed to a choice of obsessive calorie counting or inevitable weight regain. I seem to have beaten the odds and lost weight down to a normal weight, but I've gained three or four pounds since I hit my near-target weight back in December. Right now I'm hovering right at the borderline between "normal" and "overweight" BMI, and I'm happy that the weather has warmed up to the point where I'll be able to get an hour and a half of daily exercise riding my bicycle to work and back.
Looking at the studies Kolata reviews, though, I wonder if part of the reason I've found it hard to keep up with my WHEE reviews lately is due to the fact that I'm no longer losing weight. Has my interest in WHEE been a response to weight loss, much in the same way that Keys's subjects developed an obsessive interest in eating and cooking? I've written 67 diaries on WHEE since late July of last year - that's more than eight diaries per month, almost two diaries per week. Has that interest in "Weight, Health, Eating, and Exercise" been driven by the same impulse that led Hirsch's patients to obsess over food? If so, perhaps my recent difficulty in getting around to writing my twice-weekly chapter reviews (for Kolata's and Wansink's books) is due to the fact that my weight has ceased to drop. Will success spoil WHEE?
Scheduled WHEE diaries:
Thur AM - WHEE Open
Thur PM - WHEE Open
Friday AM - WHEE Open
Friday PM - Wee Mama (weekly diary)
Sat AM - bloomin (weekly diary)
Sat PM - Edward Spurlock (Wansink, Chap 4)
Sun AM - WHEE Open (Easter edition)
Sun PM - WHEE Open
Mon AM - NC Dem (Exercise of Month- Rows)
Mon PM - WHEE Open
Tues AM - WHEE Open
Tues PM - WHEE Open
Weds AM - WHEE Open
Weds PM - Edward Spurlock (Kolata, Chap 6)