The Science of Slimming
Getting rid of all those unwanted pounds is as simple as calories in, calories out. It's also as mysterious and complex as the workings of the human mind
By Amanda Spake, US News, Cover Story 6/16/03
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On a rainy Wednesday night in the meeting room at the United Methodist Church in rural Friendship, Md., some 70 people line up through the aisles of folding tables and chairs. They're waiting to be weighed. This is the weekly moment of truth, the place where these dieters will learn, officially, if all their hard work--the food diaries, the exercise, the "behavior controls"--have paid off. The scales are precise to a tenth of a pound.
Welcome to Weight Watchers. Group leader Darleen Bedard, 41, is an attractive woman with big earrings, bright clothes, and spiky blond hair. She weighed 221 pounds four years ago but has dropped a third of that. Recent medical research shows that, compared with solo dieters, Weight Watchers lose more weight, and more than half maintain the loss for two years. Leaders like Bedard are one reason why--she's part role model, part counselor, part cheerleader. Tonight she's discussing every dieter's summer Waterloo: beach food.
"What is the hardest thing to handle at the beach?" Bedard asks the crowd.
"Funnel cakes!" a woman shouts.
"OK. So how do you plan to handle the funnel cakes?" Bedard responds.
"You follow someone with a funnel cake and lick their crumbs," the woman answers.
In a rush to tackle obesity, the nation's No. 1 public-health problem, researchers are for the first time applying the tools of science to popular programs like Weight Watchers, hoping to offer serious guidance to legions of dieters looking to get leaner and healthier. Obesity researchers now find their proposals welcomed by health funders who, just five years ago, believed that only smoking warranted serious attention. Besides Weight Watchers, there are studies underway on Internet counseling, various popular diets, and social and psychological strategies used by "successful losers" to maintain weight loss.
It's about time. Americans spent about $40 billion last year on weight-loss products, programs, and diet aids. Federal surveys show that 29 percent of men and nearly 44 percent of women are trying to lose weight on any given day. Indeed, losing weight is so important that according to a recent survey, 88 percent of dieters said they would forfeit a job promotion, retirement with full pay, or a dream house if they could simply reach and maintain their target weight.
Unhappily, the mere desire to be thinner is not enough. Statistics from the federal Centers for Disease Control and Prevention show that America has never been fatter: Sixty-four percent of Americans are now overweight, and 31 percent are obese (defined as a body-mass index of 30 or above, or about 20 percent over a healthy weight). Yearly medical spending on obesity has reached $92.6 billion, about half financed by Medicare and Medicaid. But often the greatest costs are personal. Jeffrey Schwimmer, a pediatric gastroenterologist at the University of California-San Diego, found that severely obese children--who often become severely obese adults--were five times more likely to report an impaired quality of life than healthy kids. In fact, their quality of life was comparable to that of children with cancer. "Obesity is now arguably the most important cause of adult morbidity and mortality," says Schwimmer.
So what constitutes a "successful" weight loss? "The old concept of an `ideal weight' is losing credibility," says Yale psychology Prof. Kelly Brownell. "We know that modest weight loss can produce impressive health benefits." For example, studies of weight-related illnesses show that a loss of just 7 percent of body weight--if it is maintained--reduces the incidence of diabetes by 58 percent. And losing 10 pounds lowers blood pressure in people who are borderline hypertensive.
Reducing the national waistline requires a major shift in thinking about weight control. Gone are the days when weight control was instinctual, when food was scarce and humans had to be active just to survive. "We're never going to go back to an environment where we don't have to worry about weight," says James Hill, director of the Center for Human Nutrition at the University of Colorado. "We're not going to give up our cars and our remotes. And we have all these biological mechanisms relating to appetite and hunger that encourage eating."
As a result, says Hill, "we have to use our brains to restrict those instincts." This requires a conscious commitment to controlling eating and increasing physical activity. And--here's the really hard part--it's not for a week, but for a lifetime. Americans are only beginning to accept this new paradigm. Though most want to lose weight, only 1 in 5 is actually eating fewer calories and exercising for 30 minutes or more each day. "Essentially," Hill adds, "we have to teach people to override their biological instincts with their cognitive abilities."
Kenny Roberts and his best friend, Rick Marks, are learning to make the best of the new realities. Roberts, 42, and Marks, 43, grew up together in Oxon Hill, Md. They also grew out together. In early 2002, Kenny weighed 340 pounds and Rick was at 292. "Just trying to bend over to tie my shoes was a life-threatening experience," Marks remembers. When his doctor suggested he lose weight, Marks asked "How?" He got no answer.
Fewer than half of obese adults report that their physicians even advise them to lose weight. And in a survey of overweight women, more than 75 percent said their doctors, like Marks's physician, helped them only a "slight amount" or "not at all" with weight control.
Roberts, like Marks, suffered from a variety of health complaints: difficulty breathing, numbness in his hands, dizziness. His epiphany came one day in his office when he couldn't speak and his entire left side went numb: "It scared the bejeezus out of me."
Always overweight, Roberts was teased as a child and became the brunt of family jokes as an adult. When a friend took him to a Weight Watchers meeting, he says, "I hid in back and didn't say a word." But he kept going, and in a month, lost about 10 pounds. When Marks saw him, he told his friend, "Sign me up."
Now Weight Watchers is their "boys' night out." After each meeting, they adjourn to a local bar and eatery for their one splurge of the week. "This is really the highlight of my week," says Roberts. Without realizing it, the men had hit on a strategy researchers now know dramatically improves success: diet with a friend. In one program, participants who joined with friends lost 33 percent more weight in 10 months than those who tried to go it alone, and 66 percent (compared with 24 percent of the solo dieters) kept the pounds off. One new tool to reduce diet isolation is E-mail behavioral counseling. When combined with an Internet tutorial, dieters corresponding with a psychologist via E-mail lost twice as much weight as those dieting alone.
Ego boost. Marks and Roberts have each lost more than 85 pounds over 18 months. For Roberts, the shocking aspect to weight loss has been his increased confidence and self-esteem. "If you had told me I could feel this way about myself and it would cost me $100,000," he says, "I would have found a way to make the payments."
Scientists and health officials have long believed that the key to reversing obesity was education, offering the public information about healthy food choices. Most government programs aimed at weight control are based on this principle. "But in my mind," says Yale's Brownell, "the most important thing in weight loss is motivation."
Brownell believes that the national obsession with thinness, along with medicine's fixation on weight charts and body-mass index, has hindered, not helped, weight-control efforts. "One major way of undermining motivation," he says, "is to expect more than you can accomplish."
Recent studies of dieters' expectations underscore his point. Women seeking obesity treatment said that their goal weight was about 32 percent less than their current weight--close to an "ideal" weight based on standard height/weight charts. But most obesity programs, offering even the best in nutritional education and behavioral counseling, achieve only about a 10 percent loss within six months. What's more, the women in this study said that even a 25 percent loss in six months was "one I would not be happy with," and a 17 percent loss was "one that I could not view as successful in any way." As a result, many disappointed dieters feel they've failed and give up, only to regain the weight they've lost. Says Brownell: "Our challenge is to help people be happy with a modest weight loss and maintain it over time."
No one knows how important realistic expectations are better than LaVonnia "Bonnie" Johnson. In 1992, Johnson was a single mother of three, living in the projects in Washington, D.C. Her former husband had just died of AIDS. She'd landed a job in the city government, but to make ends meet, she also worked weekends in a hospital emergency room. One day a doctor took her aside and said: "Bonnie, you're only 38 and you weigh 230 pounds. You're not going to see your kids graduate from high school unless you do something about your weight right now."
Like many others, she had lost weight but regained it. An ad for a fitness club caught her eye, so she joined. Her kids and work schedule made exercise a challenge, but she found motivation in an unlikely source: pop icon Tina Turner. "She appeared on the cover of Essence magazine," Johnson says. "I looked at that cover and there she was. She'd been abused by Ike. She'd had trouble with her kids. And she had legs to die for."
Johnson taped the picture to her computer at her office and headed out every day to swim, walk on the treadmill, and bike. Progress was slow, and she wanted to quit. Then, a trainer suggested she take a step aerobics class. At first, she was so self-conscious she clung to the back wall. "But I kept thinking about the trainer saying I needed to push myself. So I moved to the front so I could see myself in the mirror."
Next, she eliminated fast foods and much of the sugar and fat from her diet. She also reduced portion sizes and started lifting weights and walking everywhere. She has now lost 65 pounds, but it has taken her 11 years. At 165 pounds, Johnson isn't thin, but she is fit. She works out twice a day, doesn't drink caffeine, and allows herself beer or wine only on weekends and special occasions. (Studies show that wine, especially, is associated with eating more.) Now that she has maintained her reduced weight for five years, she is among the 3,000 "successful losers" who make up the National Weight Control Registry, the largest collection of weight-loss success stories in the world (
http://www.lifespan.org/Services/BM...WCR/default.htm). Using data drawn from the registry, scientists hope to identify how to achieve long-term weight control. "Virtually all of the people in the registry had tried to lose weight before, often many times, and had either regained it or failed to lose," says Rena Wing, a professor of psychiatry at Brown University and a registry founder. "So the same people who are now successful were previously unsuccessful, and that's an important message: Keep trying."
Strategies. Successful losers always mention behavioral strategies such as keeping a food journal, weighing often, eating breakfast to reduce late-day hunger, and exercising religiously--about 60 to 80 minutes a day. Three in four walk regularly, and nearly all eat a low-calorie, low-fat diet--about 24 percent fat. "Nobody," says Wing, "is maintaining their weight loss with a diet low in carbohydrates."
Indeed, the great diet debate--Atkins or Ornish or something else--is unhelpful, researchers say. "People have this horse-race mentality," says Brownell. "As if you line all the diets up, and ring the bell, one of them will cross the finish line first." Stanford University professor Christopher Gardner has set up just this sort of head-to-head competition. In a trial with 300 women over three years, Gardner is testing the Atkins diet, the Zone diet, the Ornish diet, and Brownell's own low-calorie program. His study will evaluate the number of pounds lost on each, as well as changes in blood pressure, insulin, cholesterol profiles, percentage of body fat, appetite, food preferences, and more. The essential problem with diets, Gardner says, is that people don't stay on them long. The average weight-loss attempt is four weeks for women, six for men. "So until you pick something that's going to last all your life," he adds, "you haven't found the `right' diet."
And in the end, there may be no "right" diet. Michael Hamilton, former medical director of the Duke Diet and Fitness Center, the Pritikin Longevity Center, and now a researcher at the Pennington Biomedical Research Center at Louisiana State University, says food is not the key to weight control anyway; exercise is. "And we have to struggle to get enough physical activity nowadays," Hamilton adds. A study released last month by the CDC shows just how great that struggle has become. About half of U.S. adults say they walk during their usual daily activities. More than a third primarily sit. And less than a third engage in any regular leisure-time physical activity.
"The important research to be done now," says Brownell, "is not to find the best weight-loss diet, but to find the factors that make different weight-control programs work for different people. It doesn't matter what's popular, or what your neighbor did, or what you saw on TV. It matters what works for you."
"The Science of Slimming"
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