The Skinny on Fat
If biology got us into this fix, perhaps brains can get us out

JUMP START: In this North Hampton (N.H.) School gym class, students keep moving while building strength and stamina. Clockwise from front left: Kelly Burke, Stephen Damianos, Connor Glendon and Kyra Sarazen.

Kimberly Cals grew up tall, blond, and slim. Even in her 20s, it seemed she could eat no wrong. But over the years the pounds started creeping up. By her late 30s, she was about 20 pounds overweight, although she hid it well on a 5'9" frame. She knew she needed to lose weight, but her always-on-the-go lifestyle as a single mom, full-time administrative assistant and part-time college student at UNH left little time for exercise or cooking. She often skipped breakfast, downed a bag of M&M's for a snack, ate her favorite steak-and-cheese sub over a book at lunch, and picked up a fast-food dinner on the way home from a school activity with her teenage daughter.

It's a story that has become nearly universal in America today, where so many of us are overbooked and overweight—or in imminent danger of becoming so. Researchers say roughly 65 percent of Americans are overweight or obese, and a new study suggests that seven out of 10 women and nine out of 10 men in this country will eventually become overweight, even if they have made it to middle age with a sleek physique.

From left, Kyra Sarazen, Hannah Tymochko and Abby Lawlor.

To James O. Hill '78G, '81G, an internationally recognized expert on obesity, these statistics are not surprising. His own research reveals that the average American adult is gaining one to two pounds a year. "In the current environment," he writes in the journal Science, "people who are not devoting substantial conscious effort to managing body weight are probably gaining weight." The problem, he believes, has a biological basis: There is a mismatch between our ancient genes and our modern lifestyle. Eat, drink and be lazy, our genes tell us, for tomorrow we face famine—or at least a grueling trek in search of food. Alas, food is all too easy to find these days, and technology has eliminated even those tiny energy-burning treks we used to take to the TV to change the channel.

"If maintaining weight is something you now have to think about," says Hill, who directs the Center for Human Nutrition at the University of Colorado, "then we have to start equipping people to do a better job."

ALTHOUGH CALS WAS far from obese when she decided to lose weight, new research on fat reveals the wisdom of exerting mind over matter—before the matter takes control. "Once you get to a certain weight, the whole endocrine system is off," says UNH cellular biologist Deena Small, who studies how undifferentiated cells become fat cells, which can happen at any stage of our lives. "Fat is now considered a dynamic endocrine organ that responds to signals in the body, but also makes its own signals." These signals affect immunity, reproduction and brain chemistry. Unfortunately one of their favorite messages is: Make more fat. For some of us that message comes through extra loud and clear. Hill has found that, in contrast to lean people, both the obese and formerly obese respond to a meal with heightened activity in the areas of the brain that control anticipation and reward.

It was when he studied the interplay of brain chemistry and food intake as a graduate student in physiological psychology at UNH that Hill first became interested in obesity. Since then, he has looked at the problem from virtually every angle. He is the author of more than 250 scholarly journal articles and book chapters, and it's difficult to find an organization in the field that he hasn't led. Some of his studies are highly technical; others address commonly asked questions. Are people who follow a consistent diet more successful at maintaining weight loss than those who loosen up on weekends and holidays? (Yes.) Does a structured commercial weight-loss program work better than self-help? (A little.) Does excess dietary fat lead to more body-fat accumulation than excess carbohydrates, with calories kept the same? (Yes.) Does weight-loss maintenance get easier over time? (Yes.)

FOOD FOR THOUGHT: Now that Kimberly Cals '04 (above, with daughter Sammie) has taken a weight management class at UNH, she pays more attention to what she eats. "If I want a cookie," says Cals, "I have a cookie. I just don't have four."

At first, Hill didn't worry about the practical application of his findings. "Much of the time we do research and stop there and just assume somebody is going to do something with it," he explains. "But that wasn't being done." In 1999, he co-founded the National Weight Control Registry to study the characteristics of people who have lost at least 30 pounds of weight and kept it off for at least a year. Hill and his colleagues have learned much from its 6,000 members.

Unless you have five or six hours a day to devote to exercise, you're going to have to restrict calories to lose weight," says Hill, "but it almost doesn't matter what diet you choose. There are a lot of ways to lose weight, but not a lot of ways to keep it off." Those who succeed generally monitor their weight carefully, choose a low-fat diet and rarely, if ever, skip breakfast. They also get plenty of exercise, which can largely free them from the necessity of having to restrict calories. In fact, it may take 60 minutes a day of activity or more, though not necessarily all at once, to maintain a large weight loss.

One of the registry's "successful losers"—we'll call her "Adele"—lost 160 pounds by limiting portions, cutting fat intake and walking. She has since maintained her weight for more than four years by biking, lifting weights and doing yoga. She's shown friends and relatives that DNA does not equal destiny: "People told me fat was in my genes and there was nothing that could be done about it," Adele reported on the registry Web site. "I say, my 'jeans' are now size 11/12!"

IN ONE OF HIS STUDIES, Hill found that successful weight loss is often triggered by a medical event. For Adele, the trigger was more geophysical than medical. When an earthquake knocked out the elevator in her building, she acknowledged that at age 36—and 325 pounds—she couldn't make it up the stairs to her own apartment.

Kimberly Cals' motivation to lose weight did come from a medical event, but not her own. When her mother was diagnosed with terminal cancer at age 63 in 2003, Cals decided to change her own lifestyle, and signed up for the 10-week UNH weight management program. "I knew nutrition could affect certain cancers," she explains, "and here I was eating all this junk food. Plus I worried that my daughter, Sammie, would develop some of the same bad habits."

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