Weight Watchers Points Calculator

Lauren Cooper is attached at the hip to her iPhone — “Seriously, it’s a problem,” she says — so when she decided to track her diet and exercise, downloading an app made perfect sense. Cooper, a project manager in Columbia, S.C., now tabulates her Weight Watchers points using one app. Another app acts as a digital coach, urging her toward running a 5K.

“I sit at a computer all day, so the last thing I want to do when I get home is sit at a desk and enter what food and activity I’ve done for the day,” Cooper told LiveScience. “Having it on my phone just makes it easier to remain accountable.”

Cooper is one of thousands of smartphone users who use, or at least download, apps that aim to change health-related behaviors, from quitting smoking to climbing more stairs. The most popular source for apps, the iTunes App Store, doesn’t give out download information, but the top-rated free “weight loss” app in the Android Market, an exercise monitor called CardioTracker, has been installed on smartphones between 1 million and 5 million times.

But despite this popularity, there has been little research on how well apps work, or even if any comply with known public health guidelines on how to change people’s behaviors. Early studies suggest that nearly all antismoking apps fail to connect users to proven methods that help people quit smoking. Weight-loss apps fare slightly better.

“We have within the field of public health what I like to refer to as ‘tools versus toys,’ ” Erik Augustson, a psychologist in the tobacco control research branch of the National Cancer Institute (NCI), told LiveScience. “It’s very easy to become enamored with whatever the latest technology is, without thinking about, ‘Is this in fact a technology that can be leveraged to help with behavior change? ‘”

Public health researchers are optimistic that apps will be one of those technologies that prove helpful. As of September 2010, 28 percent of all cellphone users had a smartphone, according to a Nielsen Company report. And the rate of smartphone adoption is increasing — even among lower-income groups that public health researchers often struggle to reach, Augustson said.

“The main advantage of what these new technologies are offering us is the ability to reach and potentially engage very, very large numbers of people, and people from really diverse backgrounds,” he said.