People looking to lose weight might try picking up a smartphone.

Within the Wild West world of smartphone app development are many weight-loss applications that abide by at least a few of the methods clinically proven to help people drop pounds, a new study finds.

The best, said study researcher Emily Breton, is the SparkPeople app. On the other end of the spectrum are apps like the one that recommends putting your vibrating phone on your belly, supposedly to shake apart fat cells.

“We actually found, oddly enough, that the majority of the apps did provide evidenced-based information,” said Breton, who conducted the research during her graduate work in public health at George Washington University. “I expected to find that more of the apps had fluff.”

Finding that the apps are based partially on solid science doesn't prove that they work, Breton cautioned. To show efficacy, you'd have to know if people actually use the apps and stick to the weight-loss rules. But the new study does suggest that apps have potential for tackling America's obesity problem, Breton , told LiveScience. [Read: 7 Diet Tricks That Really Work]

“There definitely needs to be more research about these types of apps and what they contain,” Breton said.

Downloading health

Smartphone users have downloaded millions of health-related apps, but there has been almost no research to find out whether they work. Part of the difficulty in evaluating apps, Breton said, is how fast they proliferate. Her study, published in the Journal of Translational Behavioral Medicine, examines the 204 weight loss-related apps that were available in the iTunes store in September 2009. Since then, she said, many more have become available.

Breton and her colleagues evaluated each app based on 13 criteria established by the Centers for Disease Control and Prevention, the National Institutes of Health, the Food and Drug Administration and the U.S. Department of Agriculture for weight-loss programs.

The criteria included whether the app assessed weight, encouraged eating fruits and vegetables, encouraged physical activity, encouraged drinking water over juice or soda, included a food diary component, and encouraged a balance between calories consumed and calories burned. Ideal programs  also would encourage a moderate weight loss of 1-2 pounds (0.5 to 0.9 kilograms) per week, focus on food-portion control and the reading of nutrition labels, provide a way to track weight and physical activity, and include a meal planner and a social-support component.

Science and smartphones

A handful of apps in the store were downright humorous, Breton said, including the one that advised vibrating fat cells away. A few others recommended unhealthy techniques such as drinking lemonade all day or eating only apples, she said. [Read: 7 High-Tech Helpers to Get Fit]

But for the most part, the apps were at least somewhat based in science. Only 6 percent met none of the 13 criteria, the researchers found. A quarter had just one good component, and 30 percent had two. Another quarter encouraged three or four desirable weight-loss methods.

The best program, Breton said, was the free app SparkPeople, which had 12 of the 13 components, lacking only social networking.

“Very few apps, it was 3 percent, had social components,” Breton said. “That was a big surprise.”

Since the study, Breton said, SparkPeople and many of the other apps have  added links to an online social-networking site.

For users trying to choose the best app for their own lifestyle, Breton suggested checking out user ratings; the study found that the higher the user ratings for a given app, the more likely it was to conform to science-based standards.

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