Used alone, apps for weight loss are quite ineffective

Used alone, a cell phone app that tracks exercise, calories and weight loss goals on an average is not enough to create meaningful weight loss in young adults, according to a new study.

The randomised study included 365 people of ages 18 to 35 who were overweight or obese.

"Thirty-five percent of this age group is overweight or obese, and that's a huge public health problem," said study's lead author professor Laura P. Svetkey from Duke University School of Medicine.

One group of participants used a free Android app called CITY (Cell Phone Intervention for You), which was designed exclusively for the study.

Like many commercially available cell phone apps, CITY could be used to track calorie intake, activity and weight loss goals, and also offered weight loss tips and opportunities to connect with other users for social support.

On average, participants who used the app lost about two pounds after two years - no more than participants in a control group that received paper handouts about exercise and nutrition.

"For some people it did work. But on average, the difference with the control group was insignificant," Svetkey said.

In a separate arm of the study, participants received personal coaching from a weight loss coach. Coaches met with participants weekly for six weeks, and then followed up with monthly phone meetings.

Members of the coached group lost more weight on average than both the control group and the cell phone group - about eight pounds after 12 months, compared to about five pounds in the control group.

The findings were published online in the journal Obesity.