Women who lose weight again and again but gain it back every time, are not putting their health at risk, a new study out in the Archives of Internal Medicine shows.

"It is really hard to keep weight off once you've lost it, but our data would suggest it's worth trying," Dr. Alison E. Field of Harvard Medical School in Boston, one of the researchers on the study, told Reuters Health.

Some studies have linked so-called "weight cycling" to health risks, but much of this research hasn't separated intentional from unintentional weight loss, Field and her team note in their report. This is important, they add, because people who lose weight unintentionally are often smokers or in poor health. Nevertheless, the researcher noted in an interview, the findings were sending out the confusing message that, for some, even trying to lose weight could be harmful.

To investigate whether intentional weight loss might be risky, the researchers followed 44,882 women 30 to 55 years old for 20 years. During that time, 18.8 percent lost and regained at least 10 pounds at least three times; these women were characterized as mild weight cyclers. Another 8 percent were severe weight cyclers, meaning they lost and regained at least 20 pounds at least three times.

Both mild and severe weight cyclers gained more pounds during follow-up than the non-cyclers did, the researchers found. But neither mild nor severe weight cycling was related to mortality from any cause or death due to cardiovascular causes.

The findings back up other research in people of many ages that shows short-term diets don't work, and may actually cause people to gain more weight over time, Field noted. "Dieting is a strong predictor of weight gain," she said. "I do think we need to move people away from this dieting mentality."

Instead, the researcher added, people need to focus on making long-term, gradual changes, like drinking less non-diet soda or eating smaller portions, for example. People who exercise also seem to have an easier time keeping the weight off, she added.

"Make small changes you can stick with," Field said. "The weight won't come off as quickly, which may be frustrating especially as we're coming into bathing suit season, but that weight's going to stay off."