by Atul Gawande
It is hard to contemplate the human appetite without wondering if we have any say over our lives at all. We believe in will—in the notion that we have a choice over such simple matters as whether to sit still or stand up, to talk or not talk, to have a slice of pie or not. Yet very few people, whether heavy or slim, can voluntarily reduce their weight for long. The history of weight-loss treatment is one of nearly unremitting failure. Whatever the regimen—liquid diets, high-protein diets, or grapefruit diets, the Zone, Atkins, or Dean Ornish diet—people lose weight quite readily, but they do not keep it off. A 1993 National Institutes of Health expert panel reviewed decades of diet studies and found that between 90 and 95 percent of people regained one-third to two-thirds of any weight lost within a year—and all of it within five years. Doctors have wired patients’ jaws closed, inflated plastic balloons inside their stomachs, performed massive excisions of body fat, prescribed amphetamines and large amounts of thyroid hormone, even performed neurosurgery to destroy the hunger centers in the brain’s hypothalamus—and still people do not keep the weight off. Jaw wiring, for example, can produce substantial weight loss, and patients who ask for the procedure are as motivated as they come; yet some still end up taking in enough liquid calories through their closed jaws to gain weight, and the others regain it once the wires are removed. We are a species that has evolved to survive starvation, not to resist abundance.
The one group of human beings that stands in exception to this doleful history of failure is, surprisingly, children. Nobody would argue that children have more self-control than adults; yet in four randomized studies of obese children between the ages of six and twelve, those who received simple behavioral teaching (weekly lessons for eight to twelve weeks, followed by monthly meetings for up to a year) ended up markedly less overweight ten years later than those who didn’t; 30 percent were no longer obese. Apparently, children’s appetites are malleable. Those of adults are not.
The revealing moment is the meal. There are at least two ways that humans can eat more than they ought to at a sitting. One is by eating slowly but steadily for far too long. This is what people with Prader-Willi syndrome do. Afflicted with a rare inherited dysfunction of the hypothalamus, they are incapable of experiencing satiety. And though they eat only half as quickly as most people, they do not stop. Unless their access to food is strictly controlled (some will eat garbage or pet food if they find nothing else), they become mortally obese.
The more common pattern, however, relies on rapid intake. Human beings are subject to what scientists call a “fat paradox.” When food enters your stomach and duodenum (the upper portion of the small intestine), it triggers stretch receptors, protein receptors, and fat receptors that signal the hypothalamus to induce satiety. Nothing stimulates the reaction more quickly than fat. Even a small amount, once it reaches the duodenum, will cause a person to stop eating. Still we eat too much fat. How can this be? The reason is speed. It turns out that foods can trigger receptors in the mouth which get the hypothalamus to accelerate our intake—and, again, the most potent stimulant is fat. A little bit on the tongue, and the receptors push us to eat fast, before the gut signals shut us down. The tastier the food, the faster we eat—a phenomenon called “the appetizer effect.” (This is accomplished, in case you were wondering, not by chewing faster but by chewing less. French researchers have discovered that, in order to eat more and eat it faster, people shorten their “chewing time”—they take fewer “chews per standard food unit” before swallowing. In other words, we gulp.)
Apparently, how heavy one becomes is determined, in part, by how the hypothalamus and the brain stem adjudicate the conflicting signals from the mouth and the gut. Some people feel full quite early in a meal; others, like Vincent Caselli, experience the appetizer effect for much longer. In the past several years, much has been discovered about the mechanisms of this control. We now know, for instance, that hormones, like leptin and neuropeptide Y, rise and fall with fat levels and adjust the appetite accordingly. But our knowledge of these mechanisms is still crude at best.
Consider a 1998 report concerning two men, “BR” and “RH,” who suffered from profound amnesia. Like the protagonist in the movie Memento, they could carry on a coherent conversation with you, but, once they had been distracted, they recalled nothing from as recently as a minute before, not even that they were talking to you. (BR had had a bout of viral encephalitis; RH had had a severe seizure disorder for twenty years.) Paul Rozin, a professor of psychology at the University of Pennsylvania, thought of using them in an experiment that would explore the relationship between memory and eating. On three consecutive days, he and his team brought each subject his typical lunch (BR got meat loaf, barley soup, tomatoes, potatoes, beans, bread, butter, peaches, and tea; RH got veal parmigiana with pasta, string beans, juice, and apple crumb cake). Each day, BR ate all his lunch, and RH could not quite finish. Their plates were then taken away. Ten to thirty minutes later, the researchers would reappear with the same meal. “Here’s lunch,” they would announce. The men ate just as much as before. Another ten to thirty minutes later, the researchers again appeared with the same meal. “Here’s lunch,” they would say, and again the men would eat. On a couple of occasions, the researchers even offered RH a fourth lunch. Only then did he decline, saying that his “stomach was a little tight.” Stomach stretch receptors weren’t completely ineffectual. Yet, in the absence of a memory of having eaten, social context alone—someone walking in with lunch—was enough to recreate appetite.
You can imagine forces in the brain vying to make you feel hungry or full. You have mouth receptors, smell receptors, visions of tiramisu pushing one way and gut receptors another. You have leptins and neuropeptides saying you have either too much fat stored or too little. And you have your own social and personal sense of whether eating more is a good idea. If one mechanism is thrown out of whack, there’s trouble.
Given the complexity of appetite and our imperfect understanding of it, we shouldn’t be surprised that appetite-altering drugs have had only meager success in making people eat less. (The drug combination of fenfluramine and phentermine, or “fen-phen,” had the most success, but it was linked to heart valve abnormalities and was withdrawn from the market.) University researchers and pharmaceutical companies are searching intensively for a drug that will effectively treat serious obesity. So far, no such drug exists. Nonetheless, one treatment has been found to be effective, and, oddly enough, it turns out to be an operation.
At my hospital, there is a recovery room nurse who is forty-eight years old and just over five feet tall, with boyish sandy hair and an almost athletic physique. Over coffee one day at the hospital café, not long after my visit with Vincent Caselli, she revealed that she once weighed more than two hundred and fifty pounds. Carla (as I’ll call her) explained that she had had gastric-bypass surgery some fifteen years ago.
She had been obese since she was five years old. She started going on diets and taking diet pills—laxatives, diuretics, amphetamines—in junior high school. “It was never a problem losing weight,” she said. “It was a problem keeping it off.” She remembers how upset she was when, on a trip with friends to Disneyland, she found that she couldn’t fit through the entrance turnstile. At the age of thirty-three, she reached two hundred and sixty-five pounds. One day, accompanying her partner, a physician, to a New Orleans medical convention, she found that she was too short of breath to walk down Bourbon Street. For the first time, she said, “I became fearful for my life—not just the quality of it but the longevity of it.”
That was 1985. Doctors were experimenting with radical obesity surgery, but there was dwindling enthusiasm for it. Two operations had held considerable promise. One, known as jejuno-ileal bypass—in which nearly all the small intestine was bypassed, so that only a minimum amount of food could be absorbed—turned out to be killing people. The other, stomach stapling, was proving to lose its effectiveness over time; people tended to adapt to the tiny stom
ach, eating densely caloric foods more and more frequently.
Working in the hospital, however, Carla heard encouraging reports about the gastric-bypass operation—stomach stapling plus a rerouting of the intestine so that food bypassed only the first meter of small intestine. She knew that the data about its success was still sketchy and that other operations had failed, and she took a year to decide. But the more she gained, the more convinced she became that she had to take the chance. In May of 1986, she went ahead and had the surgery.
“For the first time in my life, I experienced fullness,” she told me. Six months after the operation, she was down to a hundred and eighty-five pounds. Six months after that, she weighed a hundred and thirty pounds. She lost so much weight that she had to have surgery to remove the aprons of skin that hung from her belly and thighs down to her knees. She was unrecognizable to anyone who had known her before, and even to herself. “I went to bars to see if I could get picked up—and I did,” she said. “I always said no,” she quickly added, laughing. “But I did it anyway.”
The changes weren’t just physical, though. She had slowly found herself to have a profound and unfamiliar sense of willpower over food. She no longer had to eat anything: “Whenever I eat, somewhere in the course of that time I end up asking myself, ‘Is this good for you? Are you going to put on weight if you eat too much of this?’ And I can just stop.” The feeling baffled her. She knew, intellectually, that the surgery was why she no longer ate as much as she used to. Yet she felt as if she were choosing not to do it.
Studies report this to be a typical experience of successful gastric-bypass patients. “I do get hungry, but I tend to think about it more,” another woman who had had the operation told me, and she described an internal dialogue very much like Carla’s: “I ask myself, ‘Do I really need this?’ I watch myself.” For many, this feeling of control extends beyond eating. They become more confident, even assertive—sometimes to the point of conflict. Divorce rates, for example, have been found to increase significantly after the surgery. Indeed, a few months after her operation, Carla and her partner broke up.
Carla’s dramatic weight loss has proved to be no aberration. Published case series now show that most patients undergoing gastric bypass lose at least two-thirds of their excess weight (generally more than a hundred pounds) within a year. They keep it off, too: ten-year follow-up studies find an average regain of only ten to twenty pounds. And the health benefits are striking: patients are less likely to have heart failure, asthma, or arthritis; most remarkable of all, 80 percent of those with diabetes are completely cured of it.
I stopped in to see Vincent Caselli one morning in January of 2000, about four months after his operation. He didn’t quite spring to the door, but he wasn’t winded this time. The bags under his eyes had shrunk. His face was more defined. Although his midriff was vast, it seemed smaller, less of a sack.
He told me that he weighed three hundred and forty-eight pounds—still far too much for a man who was only five feet seven inches tall, but ninety pounds less than he weighed on the operating table. And it had already made a difference in his life. Back in October, he told me, he missed his youngest daughter’s wedding because he couldn’t manage the walking required to get to the church. But by December he had lost enough weight to resume going to his East Dedham garage every morning. “Yesterday, I unloaded three tires off the truck,” he said. “For me to do that three months ago? There’s no way.” He had climbed the stairs of his house for the first time since 1997. “One day around Christmastime, I say to myself, ‘Let me try this. I gotta try this.’ I went very slow, one foot at a time.” The second floor was nearly unrecognizable to him. The bathroom had been renovated since he last saw it, and Teresa had, naturally, taken over the bedroom, including the closets. He would move back up eventually, he said, though it might be a while. He still had to sleep sitting up in a recliner, but he was sleeping in four-hour stretches now—“Thank God,” he said. His diabetes was gone. And although he was still unable to stand up longer than twenty minutes, his leg ulcers were gone, too. He lifted his pants legs to show me. I noticed that he was wearing regular Red Wing work boots—in the past, he had to cut slits along the sides of his shoes in order to fit into them.
“I’ve got to lose at least another hundred pounds,” he said. He wanted to be able to work, pick up his grandchildren, buy clothes off the rack at Filene’s, go places without having to ask himself, “Are there stairs? Will I fit in the seats? Will I run out of breath?” He was still eating like a bird. The previous day, he’d had nothing all morning, a morsel of chicken with some cooked carrots and a small roast potato for lunch, and for dinner one fried shrimp, one teriyaki chicken strip, and two forkfuls of chicken-and-vegetable lo mein from a Chinese restaurant. He was starting up the business again, and, he told me, he’d gone out for a business lunch one day recently. It was at a new restaurant in Hyde Park—“beautiful,” he said—and he couldn’t help ordering a giant burger and a plate of fries. Just two bites into the burger, though, he had to stop. “One of the fellas says to me, ‘Is that all you’re going to eat?’ And I say, ‘I can’t eat any more.’ ‘Really?’ I say, ‘Yeah, I can’t eat any more. That’s the truth.’ ”
I noticed, however, that the way he spoke about eating was not the way Carla had spoken. He did not speak of stopping because he wanted to. He spoke of stopping because he had to. You want to eat more, he explained, but “you start to get that feeling in your insides that one more bite is going to push you over the top.” Still, he often took that bite. Overcome by waves of nausea, pain, and bloating—the so-called dumping syndrome—he’d have to vomit. If there was a way to eat more, he would. This scared him, he admitted. “It’s not right,” he said.
Three months later, in April, Vince invited me and my son to stop by his garage in East Dedham. Walker was four years old then and, as Vince remembered my once saying, fascinated with all things mechanical. So on my Saturday off, we went. As we pulled into the gravel lot, Walker was fairly zizzing with excitement. The garage was cavernous, barnlike, with a two-story garage door and metal walls painted yellow. Outside, it was an unusually warm spring morning, but inside the air was cool. Our footsteps echoed on the concrete floor. Vince and a buddy of his, a fellow heavy-equipment contractor I’ll call Danny, were sitting on metal folding chairs in a sliver of sunlight, puffing fat Honduran cigars, silently enjoying the day. Both rose to greet us. Vince introduced me as “one of the doctors who did my stomach operation,” and I introduced Walker, who shook hands all around but saw only the big trucks. Vince lifted him up into the driver’s seat of a front-end loader backhoe in one corner of the garage and let him play with the knobs and controls. Then we went over to Vince’s beloved Gradall, a handsome tank of a machine, wide as a county road, painted yield-sign yellow, with shiny black tires that came up to my chest and the name of his company emblazoned in curlicue script along its flanks. On the chassis, six feet off the ground, was a glass-enclosed cab and a thirty-foot telescoping boom on a three-hundred-and-sixty-degree swivel. We hoisted Walker up into the cab and he stood there awhile, high above us, pulling levers and pressing pedals, giddy and scared all at once.
I asked Vince how his business was going. Not well, he said. Except for a few jobs in late winter plowing snow for the city in his pickup truck, he had brought in no income since the previous August. He’d had to sell two of his three pickups, his Mack dump truck, and most of the small equipment for road building. Danny came to his defense. “Well, he’s been out of action,” he said. “And you see we’re just coming into the summer season. It’s a seasonal business.” But we all knew that wasn’t the issue.
Vince told me that he weighed about three hundred and twenty pounds. This was about thirty pounds less than when I had last seen him, and he was proud of that. “He don’t eat,” Danny said. “He eats half of what I eat.” But Vince was still unable to climb up into the Gradall and operate it. And he was beginning to wonder whether that w
ould ever change. The rate of weight loss was slowing down, and he noticed that he was able to eat more. Before, he could eat only a couple of bites of a burger, but now he could sometimes eat half of one. And he still found himself eating more than he could handle. “Last week, Danny and this other fellow, we had to do some business,” he said. “We had Chinese food. Lots of days, I don’t eat the right stuff—I try to do what I can do, but I ate a little bit too much. I had to bring Danny back to Boston College, and before I left the parking lot there I just couldn’t take it anymore. I had to vomit.
“I’m finding that I’m getting back into that pattern where I’ve always got to eat,” he went on. His gut still stopped him, but he was worried. What if one day it didn’t? He had heard about people whose staples gave way, returning their stomach to its original size, or who managed to put the weight back on in some other way.
I tried to reassure him. I told him what I knew Dr. Randall had already told him during a recent appointment: that a small increase in the capacity of his stomach pouch was to be expected, and that what he was experiencing seemed normal. But could something worse happen? I didn’t want to say.
Among the gastric-bypass patients I had talked with was a man whose story remains a warning and a mystery to me. He was forty-two years old, married, and had two daughters, both of whom were single mothers with babies and still lived at home, and he had been the senior computer-systems manager for a large local company. At the age of thirty-eight, he had had to retire and go on disability because his weight—which had been above three hundred pounds since high school—had increased to more than four hundred and fifty pounds and was causing unmanageable back pain. He was soon confined to his home. He could not walk half a block. He could stand for only brief periods. He went out, on average, once a week, usually for medical appointments. In December 1998, he had a gastric bypass. By June of the following year, he had lost a hundred pounds.
