Stopping that Rebound in Weight
Ask U.S. adults if they're trying to lose weight, and 3 out of 4 say "yes," polls show. Weight loss is a major industry, from support programs to diet books to special foods. Yet more than 60% of Americans are overweight, and the numbers are getting higher.
With all this dieting, why are so many people still unsuccessful at controlling their weight? One reason is that although many people manage to lose weight, they usually don't keep it off.
Even in medically supervised weight-loss programs, people often regain, says Eva Obarzanek, a nutritionist for the U.S. government's National Heart, Lung, and Blood Institute of the National Institutes of Health (NIH) and project officer of a new study on maintaining weight loss.
"In a period after weight loss, usually about six months, the weight starts going back up," she says.
Even in the best medically supervised programs, nearly two-thirds of participants are back where they started within 3 years and 80% to 90% within 5 years, says Gary Foster, Ph.D., clinical director of the Weight and Eating Disorders Program at the University of Pennsylvania.
For people who lose weight on their own, the relapse rate may be even higher.
Why is it so difficult to avoid putting those pounds back on? Biology, environment and the pressures of everyday life all play a role.
- Biology — The body's metabolism, programmed for survival in times of food shortage, works against dieters. "Your metabolism slows down because it's trying to conserve energy," Obarzanek says. "So you get hungry, your body doesn't expend as many calories as before doing the same things, and you have to reduce calories even more."
- Environment — "It's tougher to lose weight and keep weight off now than it was 20 years ago because there are so many incentives to eat more and move less," Foster says. "The cheapest foods are often the unhealthiest." Activity is reduced by labor-saving devices, sit-down entertainment such as television, and the growing number of people in desk jobs.
- Life pressures — "Weight control takes a lot of work, hard work," Foster says. "If life gets in the way — a spouse gets ill, your child is going through behavioral problems — the disposable energy that you have for any project, including weight control, gets diverted." So you go back to old habits, and you regain weight.
Is it possible to lose weight and keep it off for a long time? Plenty of highly motivated people have succeeded. Now, research is starting to provide a clearer picture of how they do it.
Some of the most detailed information comes from a national long-term study. The National Weight Control Registry contains information on 3,000 people who have lost 30 to 100 pounds (average, 60 pounds) and then kept their weight stable for at least one year (average, five years).
They lost weight using many different diets or programs, says James Hill, Ph.D., co-director of the study along with Rena Wing, Ph.D., of Brown University. But those who keep it off have several things in common, he says.
People in the weight-control registry, on average, burn up about 2,700 calories a week in physical activity, says Hill, director of the Center for Human Nutrition at the University of Colorado Health Sciences Center in Denver.
That's equal to about one hour of moderately intense activity every day — for example, five miles of walking. "I think this is the most important [factor]," Hill says.
It's not clear if people who lose smaller amounts of weight need to exercise this much. Still, a large body of research agrees that exercise is essential in counteracting the body's tendency to regain weight.
"Without exercise, the other efforts are simply temporary," says Harold Solomon, M.D., director of the Weight Loss and Lifestyle Enhancement program at Beth Israel Deaconess Medical Center in Boston. "There are very few people who can lose weight and keep it off without changing the amount of energy they expend."
Guidelines from the National Heart, Lung, and Blood Institute, part of the NIH, make the following recommendations about exercise to prevent weight gain:
- Consult your doctor and start slowly to avoid injury.
- If you have been inactive, start with 10 to 30 minutes of moderately intense activity, such as walking, 3 days a week. Build up to 30 to 45 minutes on most or all days of the week
- Reduce sedentary activities such as watching television. Build more activity into your day by parking farther from your destination, taking the stairs instead of the elevator, gardening, walking a dog, etc.
- Schedule your physical activity a week in advance, budget the time to do it, and use a diary to record the amount of time you spend exercising. Record the type of activity as well as the intensity.
People in the weight-control registry are highly disciplined about this, Hill says. "They weigh themselves a lot and they record what they eat on a regular basis."
Foster says his own experience with patients also shows that self-monitoring is important because it allows you to notice weight fluctuations early and to take action.
"This doesn't mean you get crazy about every pound you go up or down," he says, "but it does mean that this is a chronic problem and when you gain weight what are you going to do about it? The way you reverse small weight gains is to have a specific plan."
Although people in the registry originally lost weight using a variety of diets, the vast majority kept the weight off by following a low-fat, high-carbohydrate diet, Hill says.
Although new research indicates that low-carbohydrate regimes such as the Atkins diet can produce significant weight loss, very few people in the weight-control registry were following Atkins long-term, Hill says.
Another important rule is to control portion size, Obarzanek says. And, she says, "I still believe that reducing dietary fat is the most efficient way of reducing calories."
Dr. Solomon, a clinical assistant professor of medicine at Harvard Medical School, says his own patients who are successful at long-term weight control make rules for themselves about eating. Then, he says, they make those rules second nature.
For example, he says, someone who eats a salad every day, but longs for a cheeseburger, at some point will give up and eat the burger. In contrast, people who permanently lose weight often say they don't do anything special to keep it off because they have made a permanent change in how they think about food, he says.
"They have sort of drummed the cheeseburger out of their minds," he says. "They have a new reality."
This is another important element for people in the National Weight Control Registry. "They eat breakfast, so they're spreading out their calories over the day," Hill says.
This pattern is important to reduce hunger and bingeing, Dr. Solomon says. "You have to eat breakfast. You have to spread your calories out and eat at least three or four times a day."
It's difficult to keep weight off, but research indicates that it helps to have some outside support.
"We know that frequent contact with a health provider or some other entity that's looking after them — that would include a support group — is helpful," Obarzanek says. "We find in our clinic sessions that people who attend the most sessions lose the most weight."
"Unfortunately, we don't know cause and effect. If you force people to go to sessions, would you get the same effect? Maybe people who are successful are proud, so they show up."
The new NIH study on keeping weight off will explore whether certain ways of providing support are helpful. After participants lose weight, they will be randomly assigned to one of three groups.
Members of the "self-directed" group will meet once with a health counselor and will receive educational materials, but no other support. A second group will receive monthly telephone calls from a counselor and occasional visits. The third group will use an Internet-based program that includes weekly e-mails with messages related to their progress and automated phone reminders to use the system.
The form of support you need may depend on your personality, Foster says. "My sense is that in an attempt to find out what works we generalize too much. Some people are solo dieters and some like buddies. The most consistent data show that consistent contact with a professional improves the long-term outcome."
But ultimately what matters is individual vigilance, he says. "Maintenance is a very active process. If you go with the tide, you will gain weight."