NEW YORK - If you're trying to lose weight and keep it off, new research suggests you take up a diet and exercise plan that will help you lose a big chunk of weight right off the bat.

Some doctors and dieticians think that losing lots of weight fairly quickly makes it more likely that dieters will gain most of it back, and so they often encourage overweight and obese patients to lose weight in small increments.

But scientists have found that no matter how much weight people initially lose, they seem to gain back a similar percentage of that weight over the next year.

"I think there is more of a myth that if people do this very slowly they're going to ultimately be able to lose more weight," Dr. Deborah Tate, a clinical psychologist who studies obesity at The University of North Carolina at Chapel Hill who was not involved with the research, told Reuters Health.

If long-term weight is what you care about, "it should be recommended and favored that people lose a high amount of weight," said Dr. Jeroen Barte, a researcher at the National Institute for Public Health and the Environment in the Netherlands and the lead author of the new research.

Barte and his colleagues presented their findings Monday at the International Congress on Obesity in Stockholm, Sweden. Their study was also published online in Obesity Reviews in March.

The authors analyzed data from 12 different weight-loss studies covering almost 1,000 overweight and obese participants. In all of the studies, participants went through an intensive weight-loss program that gave them exercise and nutrition guidance. The programs lasted between 10 weeks and one and a half years, depending on the study.

Dieters were weighed at the beginning and end of the weight-loss programs, and again at least one year after completing the programs. The authors compared how much of their initial weight loss dieters were able to keep off for those that had lost between 5 and 10 percent of their body weight and those that had lost more than 10 percent.

The average participant started at 209 pounds and lost about 20 pounds over the course of the program. One year later, no matter how much weight they had initially lost, participants had gained back an average of about half that weight.

That meant that the dieters who had initially dropped the most weight also ended up with the best long-term results.

The findings are part of a growing number of studies that show that slow and steady weight loss might not be the way to go, said Tate. The evidence, she said, shows that "We should perhaps be encouraging better initial weight loss."

That doesn't mean that people should be dropping pounds at unsafe levels. One or two pounds per week is still the recommended rate for people trying to lose weight, she confirmed.

The authors say that future studies should follow dieters for longer than one year after their initial weight loss to truly understand the long-term impacts of that initial loss.

But for now, they say, doctors should encourage weight loss of 10 percent or more in their overweight and obese patients if the goal is to have them at their slimmest down the road.

SOURCE: link.reuters.com/cud57m Obesity Reviews, online March 24, 2010.