Wristy business of weight loss

Wearable fitness devices help people shed excess kilos, right? Actually, maybe not

Despite the popularity of Fitbits and other fitness trackers, a recent study shows using these wearable devices may actually decrease weight loss in obese and overweight adults.

In a study published in JAMA, adults using wearable fitness devices lost less weight than those receiving only standard interventions over a two-year period.

“When we gave people these strong behavioural weight loss programs … we really thought that adding these wearable technologies to the program would help them to lose more weight over 24 months,” said lead researcher Dr John Jakicic.

“And to our surprise, that actually wasn’t what we found.”

In the study, 471 young adults with BMIs between 25 and 40 were randomly assigned to a standard or technology-enhanced weight-loss intervention.

All participants were placed on a low-calorie diet, advised to increase their physical activity, and underwent group-counselling sessions, and, after six months, text message prompts and access to online study materials were added.

Also at six months, subjects randomised to the standard intervention group began self-monitoring diet and exercise using a website, while those in the high-tech group were provided with a wearable device linked to a website.

To the researchers’ surprise, those assigned to wearables had lost 2.4kg less weight after two years than those on the standard program.

The results might be explained by devices giving people a false sense of security, said Dr Jakicic. “They don’t pay attention to some of the key behaviours that they otherwise might pay attention to. They are relying on the device or the technology maybe a little bit too much.”

Professor John Dixon, Head of Clinical Obesity Research at the Baker IDI Heart and Diabetes Institute, told The Medical Republic he was not surprised the use of devices did not promote weight loss.

“What exercise is great for is to improve your fitness, your balance, your strength, and when you are losing weight, to try and preserve muscle,” he said.

“We shouldn’t think that increase of monitoring exercise is actually going to increase weight loss.”

Perhaps the technology-enabled group spent more time focused on their exercise than on their diet, Professor Dixon suggested. This would explain why they lost less weight than the other group.

But it was too early to completely ditch wearables, he said.

“You’ve got a group of people who love to use these tools, and other people who exercise regularly and have shown no interest in them whatsoever. So I think it’s each to their own.”

JAMA 2016, 20 September