Little evidence that diets work

This article describes a study finding that no weight loss programs have proof they work, except for Weight Watchers.

Only Weight Watchers had strong documentation that it worked -- with one study showing that participants lost around 5 percent (about 10 pounds) of their initial weight in six months and kept off about half of it two years later.

However, the researchers who conducted the review published in Tuesday's Annals of Internal Medicine stressed that the lack of scientific evidence should not be viewed as an attack on diet programs.

"There are no data on weight loss when you go to a health club, either," said Thomas Wadden, a University of Pennsylvania weight-loss expert and the study's co-author. "We hope that doctors and patients will use this information to make more informed decisions."