Teens' diets often backfire
Study finds boomerang effect in both sexes.
"Teenagers take their weight into their own hands when they go on diets, but not
in the way you might think.
Even when a variety of factors were taken into account, adolescents who dieted frequently
actually gained more weight each year than other children, says new research.
Both male and female dieters suffered about equally from the boomerang effect of
dieting, which appeared to boost their weight by about an average of about two pounds
per year over other teens.
"Most people who diet tend to regain the weight. In children, we're really seeing
that this is happening at a young age," says study co-author Alison Field, an assistant
professor of pediatrics at Harvard Medical School.
Field and her colleagues studied the dietary habits of 8,203 girls and 6,769 boys
who were between 9 and 14 years old in 1996. All the subjects were children of nurses,
and more than 90 percent were white.
The findings appear in the October issue of Pediatrics.
At the beginning of the study, 25 percent of the girls and 13.8 percent of the boys
were frequent dieters. Over three years, the dieting children gained more weight
on average than the kids who didn't diet. "Even after we took into account how much
they'd grown and the amount of time spent in front of the TV, we still found that
the children who were dieting gained more weight than their non-dieting peers,"
Field says.
The reasons for the weight gain aren't entirely clear, but there are several theories.
One possibility is that repeated dieting changes the metabolism of the body so it
doesn't process food as effectively. "A more likely explanation is that they're
overeating when they're not following their restrictive diets," Field says. "There's
a lot of speculation that dieting leads to binge eating, which leads to more weight
gain and more dieting."
Field, however, isn't recommending that teens avoid dieting. She says the solution
to obesity, a growing problem among young and old Americans, is a mix of exercise
and sensible eating.
"Certainly the recommendation for children and parents alike who want to lose weight
would be to make more modest changes that they can stick with - drink a can of soda
instead of a 20-ounce bottle, limit the amount of supersizing they do, and increase
physical activity."
Heidi Reichenberger, a Boston nutritionist and spokeswoman for the American Dietetic
Association, says overly restrictive diets lead to trouble among those who think
they weigh too much.
"They forbid themselves to eat any of their favorite foods. They tend to cut way
down on calories. And a lot of teens, even a lot of grownups, think if they skip
meals they'll lose weight, they skip breakfast or skip lunch," she says. "If you
do that for days or weeks, it really adds up, and it gets really hard to control
the cravings, the desires and the hunger."
The key for teens is to find an expert to give them advice about nutrition, says
Reichenberger, who works at a Boston high school. "They may be able to find one
right in their school [if] they ask their doctor or school nurse or coach."