The idea that switching from drinking soda to diet soda or water could be a simple and effective way to lose weight has been promoted for a while. Now, a new study testing out the idea finds that it not only sounds good, it also works.

Even the best sounding weight loss strategy won't work if people don't follow it. Switching from sugary soft drinks to diet soda or water is a lifestyle change that's easy for people to follow, a lot easier than cutting down on their favorite foods seems to be.

People who altered their soft drink consumption were twice as likely to lose 5 percent or more of their body weight. They also had the added benefits of lower blood sugar and better hydration at the trial's end.

Several nutritional studies have found Americans getting around 20% of their daily calories from sugar-containing beverages, chiefly soda, but also lemonade, iced tea and sports drinks. At 180 calories in a 12-ounce can of soda, these calories can quickly turn into extra pounds.

The current study is thought to be the first randomized controlled trialstesting beverage substitution as a weight loss strategy in adults. In it, 318 overweight or obese people who wanted to lose weight were divided into three groups. One group replaced their sugary beverages with diet soda. A second group replaced them with water.

A third group wasn't asked to make any changes in beverage consumption but received general information about healthy choices that could lead to weight loss. All three groups attended monthly group sessions and had access to a group-specific website for 6 months.

All three groups lost weight and trimmed their waistline over the next six months, losing an average of 2 to 2.5% of their body weight. But people in the groups who altered their soft drink consumption were twice as likely to lose 5 percent or more of their body weight than the other group was.

People who switched from soda to water also had the added benefits of lower blood sugar and better hydration at the trial's end.

While the weight loss numbers may seem modest compared to other more intensive programs, it's a very simple strategy for people to follow, requiring minimal self-monitoring and only a single lifestyle change. And the strategy proved as good or better than any strategy the third group could devise to shed pounds over the six months.

People who are used to drinking soda that contains sugar may find that diet soda tastes a little odd at first. But they're usually surprised at how quickly this fades. Of course, there's also always water, perhaps flavored with a little lemon or lime.

An article on the study is available online in the American Journal of Clinical Nutrition.