If you need to lose weight, a wearable fitness tracker may seem like a good way to help keep you on track. But one such device was actually less effective than standard behavioral methods in promoting and maintaining long-term weight loss, in a recent study in the Journal of the American Medical Association.
The two-year study involved 471 overweight or obese adults, ages 18 to 35. For the first six months, all participants received a low-calorie diet plan and were instructed to do 100 minutes of moderate activity per week and gradually increase this to 300 minutes per week. They also took part in weekly group counseling sessions.
After six months, the participants were split into two groups. One group was instructed to start tracking their diet and physical activity using a website (standard intervention). The other group received fitness trackers—devices worn around the upper arm that tracked their physical activity throughout the day; web-based software allowed for self-monitoring of dietary intake. The two groups were checked every six months for continued weight loss.
The researchers hypothesized that those who wore the trackers would lose more weight, but the opposite happened. The greatest weight loss—about 18 pounds in both groups—occurred during the first six months, before the groups were split up and half started wearing the trackers. Weight was regained at every subsequent six-month reading, but more rapidly among those using the fitness trackers. After two years, the fitness trackers group had lost an average of 8 pounds, compared with 13 pounds in the self-monitoring group.
Despite getting ongoing feedback on their calorie burning from their devices throughout the day, the tracker group got no more exercise on average than the group that didn’t wear trackers. And there were no significant differences between the groups in other outcomes, such as body mass index, fat mass, and cardiorespiratory fitness.
“Although this study showed weight loss across the 24-month intervention in young adults, similar to trials of middle-aged and older-aged adults, the benefits achieved at six months were not fully sustained long term,” the researchers noted. “Thus, regardless of age, challenges remain to preventing or minimizing weight regain following initial weight loss in adults.” They said that more research is needed to determine why adding a wearable technology to a standard diet intervention would result in less, rather than more, weight loss.
Bottom line: If you need to lose weight and enjoy using a fitness tracker, there’s no reason to stop, but it may make more sense to use it in addition to—not in place of—the tried-and-true method of tracking your food intake and activity level through a journal, whether on paper or through a website or app.