Young American adults own smartphones at a higher rate than any other age group. And researchers from Duke University wanted to see if capitalizing on that smartphone usage with a low-cost weight-loss app might help the 35 percent of young adults in the U.S. who are overweight or obese.
If you're rooting for smartphones to solve all our health problems, you're not going to like what the researchers found. The smartphone app didn't help young adults lose any more weight than if they hadn't been using the app at all.
The study, published in the journal Obesity, looked at 365 young adults ages 18-35. A third of the participants used an Android app specifically created for the study, which not only tracked their calories, weight and exercise but also offered interactive features such as goal setting, games and social support.
Another third of the participants received six weekly personal coaching sessions, followed by monthly phone follow-ups. Plus, this personal coaching group was also encouraged to track their weight, calories and exercise via smartphone.
The last third of the participants were given three handouts on healthy eating and exercise – nothing else.
Researchers tracked the young adults' progress after six months, one year and two years. The personal coaching group had lost more weight than the other two groups after six months, but that lead vanished at the one- and two-year follow-ups.
As for the group using the smartphone app, their average weight loss was never more than the other two groups.
Lead author Dr. Laura Svetkey said she and her colleagues were both surprised and disappointed at the results.
"Given the seeming power of cellphone apps and frankly the popularity of these health and fitness apps in the commercial world, we thought this might be a really good strategy to provide effective intervention very broadly and potentially at low cost," said Svetkey, a professor of medicine at Duke University School of Medicine.
Yet, Svetkey says, it's difficult to get the same level of intensity in an app that you might get through personal coaching, and people have the tendency to stop using weight-loss apps after a while.