Activity trackers have limited advantage in weight loss efforts, study finds

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If your FitBit is every bit as essential to your day-to-day life as food and water, you might want to reassess your wearable habit. Research published in the Journal of the American Medical Association found that overweight people who began using fitness trackers six months into a two-year weight loss programme lost less weight overall than those who didn't.

The University of Pittsburgh study had 470 people with BMIs of 25-40 undertake a low-calorie diet, increased physical activity and group counselling sessions for six months. After this, one group had to self-monitor their diet and activity using a website, while the other group were given wearable activity tracking devices.

At the end of the study, it was found that the group with activity trackers weighed about 8 pounds less than at the start, in contrast to the other group who weighed on average 13 pounds less. While the extra weight in the activity tracker group could be put down to muscle gain, the data showed that those wearing them actually exercised less than the other group.

Dr John Jakicic, the lead author of the study, said his team had been "pretty confident" that the participants with activity trackers would lose more weight. "We were definitely surprised [with the results]," he said. "People may have focused on the technology and forgotten to focus on their behaviours."

If the participants were basing their dietary intake on the activity tracker's calorie count, this could also have caused a problem - calorie counts from wearables are notoriously inaccurate.

“There’s probably a time and place for wearables, and there’s so much more we need to learn about them,” Jakicic says. “For the person who finds wearables engaging, absolutely use them.” All in all, activity trackers aren't totally useless - the participants using them did lose weight, after all - but it's worth focusing on more (diet, activity levels) than the metrics they provide.