Teens and Dieting a Losing Proposition

Dieting, like dating and driving, is a time-honored ritual for many teens.

But it's often not a productive -- or even healthy -- one.

New research suggests teens who diet frequently tend to gain more weight each year than children who don't diet. One likely explanation: Many teens resort to diets that greatly limit what and how much they can eat. Then they abandon those food plans with a vengeance, overeating and regaining all the lost weight -- and often more.

"Most people who diet tend to regain the weight. In children, we're really seeing that this is happening at a young age," says Alison Field, an assistant professor of pediatrics at Harvard Medical School and co-author of a recent study on teens and dieting.

The findings come amid growing concern about childhood obesity and the attendant health threats, which include the potential for heart disease, diabetes and cancer as the children grow into adulthood. The prevalence of overweight has increased by 100 percent among U.S. teens in the last two decades. And almost 14 million children -- 24 percent of the population aged 2 to 17 -- are obese, with an additional 8.6 million children at risk for obesity, according to federal statistics.

But the answer to the weight epidemic isn't restrictive or fad diets. What's needed are lifestyle changes. Programs that teach teens and preteens how to eat nutritiously, get enough exercise and cut down on TV and computer time are much better avenues to lifelong weight control, experts say.

The "boomerang effect" of dieting and then regaining the weight is well-known to many adults who've tried to shed pounds. But it's also a very real problem for teens, according to the Harvard study that was published last fall in Pediatrics . The researchers studied the eating habits of nearly 15,000 girls and boys who were between 9 and 14 at the start of the study in 1996. Twenty-five percent of the girls and 13.8 percent of the boys said they dieted often when the study began.

As the researchers tracked the children for three years, they found the kids who dieted actually gained more weight on average than those who didn't. The dieters picked up about two pounds per year, compared to the non-dieters.

Frequent dieting may alter the metabolism so it doesn't work as quickly. Or it may lead teens on restrictive diets to abandon them and start eating too much, experts say.

Whatever the explanation, nutritionists concur that restrictive diets aren't the answer.

"Get away from the mentality of a diet," Bettye Nowlin, a registered dietitian from Calabasas, Calif., and a spokeswoman for the American Dietetic Association, tells teens trying to slim down. "Try to put the focus on healthy eating and lifestyle changes."

"If they are exercising and eating proper diets, they should lose weight," she adds.

When Nowlin counsels teens, she tells them to watch portion sizes. And rather than eliminate favorite high-fat foods, she urges teens to classify them as "sometime" food. French fries, for instance, might be a once-a-week "sometime" food. "And when you have them, get the small size," she suggests.

Marilyn Tanner, a registered dietitian who runs a program for overweight teens at St. Louis Children's Hospital, urges a similar approach. She doesn't mention "dieting" when working with kids.

"By the time they come to us they have already dieted and continued to gain weight," says Tanner, a pediatric dietitian at the Washington University School of Medicine in St. Louis and a spokeswoman for the American Dietetic Association.

"Our program is a lifestyle program," she says. "We concentrate on goals they can strive for, such as less inactivity."

"The kids wear pedometers," she adds. "We find out what their baseline steps are [each day] and add 100 steps or more."

"We don't promise they will lose weight, but tell them what to do to eat healthier," Tanner says. "We weigh them in, but it is their option to see what the number is. Our goal is to stop the gain. Our kids are slightly overweight, such as 10 pounds, to obese."

During the 10-week program, the kids learn the basics of nutrition, such as proper portion sizes, which can go a long way toward weight control. "A serving of rice is one-third of a cup," Tanners says. "Some kids get those big white containers [from Chinese carryout restaurants] for fried rice."

They also learn about calories and a goal to shoot for daily, such as 2,000, depending on their height, weight and activity levels. "Some kids drink the equivalent of 1,000 calories a day in soda," she says.

"We encourage five [servings] a day of fruits and vegetables. We tell them to watch their fat intake," Tanner adds.

Once they follow the program for a while, she says, many "grow into their weights." But not all of them do. If that's the case, they can work on weight loss once the healthy habits are ingrained.

The "healthy habits first" approach will eventually pay off, Tanner says, and hopefully help teens control their weight for a lifetime.

More information

Learn more about nutrition and dieting for children, visit the American Dietetic Association.