Activity trackers may not give you a weight-loss edge after all

Using wearable activity monitors to count your steps may not help you lose weight as promised. In fact, more weight loss might be achieved without them.

That's the conclusion of a study published Tuesday in the Journal of the American Medical Association that found people who used activity trackers lost five pounds less than those who didn't. The results surprised researchers, who believed wearable technology would help people lose more weight.

"[Researchers] actually anticipated that those with the activity trackers would lose more weight across the 24 months," said study coauthor John Jakicic, a weight-management researcher at the University of Pittsburgh. "When we found just the opposite this was very surprising."

The study followed 471 overweight or obese adults, ages 18 to 35 years old, for two years as they participated in a weight-loss program that focused on exercise, a healthy diet and weekly support meetings. After six months, one group began using a website to self-monitor their caloric intake and physical activity, while the other group was a commercially available monitor worn on the upper arm that tracks physical activity.

After two years, the group wearing trackers lost an average of nearly 8 pounds, while the group using only Web-based tracking lost an average of 13 pounds.

Jakicic said weight loss is more complex than simply monitoring your activity, noting that poor dietary practices can easily offset the benefits of energy expended during physical activity. He also said activity trackers don't take into account barriers that individuals face in maintaining a healthy diet or physical activity.

"I think that the public may have a perception that all they need to do is wear a device like these and things will be much easier for them," he said. "Regardless, if you wear a device like this and it helps you to become more active and manage your weight better, by all means keep doing that."