People who stayed on their diet for a full year experienced the most weight loss. Study results showed a 6 percent weight loss for the Ornish program participants, a 5 percent weight loss for those on both Weight Watchers and the Zone diets and a 4 percent weight loss for Atkins dieters.
Even with a moderate weight loss, participants significantly reduced their heart disease risk -- by 5 percent to 15 percent on average.
For the study, 160 overweight people were randomly assigned to one of the four diets. They followed a supervised program for two months and were left to continue the diets on their own. After only two months, 22 percent quit the study. After a year, 35 percent dropped out of Weight Watchers and the Zone diets, and 50 percent quit the Atkins and Ornish plans.
The researchers said the study suggests there is no one-size-fits-all diet best for everyone and any diet can work if it helps someone eat less and lose weight.
So while this study does seems to conclude that any diet can work, the drop-out rate raises other issues. It may be that finding and sticking with a balanced approach to eating for life is still the best long-term solution to maintaining a healthy weight.