番茄社区

Use of wearable devices tracking physical activity failed to boost weight loss over and above standard interventions in a 2-year randomized trial, researchers said.

In the IDEA (Innovative Approaches to Diet, Exercise and Activity) study, which assigned overweight and obese adults to interventions with and without fitness trackers, both treatment arms lost weight, but the loss was greatest in the standard intervention group after 24 months (5.9 kg versus 3.5 kg with fitness tracker use, P=0.003), according to , of the University of Pittsburgh, and colleagues.

Nor was there an additive benefit for fitness trackers at the trial's end for other outcomes, such as body mass index, fat mass, body fat percentage, and cardiorespiratory fitness, the researchers reported in .

Some earlier studies had found that fitness trackers could boost short-term weight loss, prompting the current study to evaluate the durability of such benefits.

Jakicic and colleagues concluded, "Devices that monitor and provide feedback on physical activity may not offer an advantage over standard behavioral weight loss approaches."

Jakicic told 番茄社区 that his group expected a different outcome. "We originally hypothesized that the technology would enhance weight loss at 24 months in our study. So, to find that it actually reduced weight loss success across 24 months was a bit surprising," he said.

"However, these findings are very important because they suggest that, just because in theory these technologies should help with health behavior change and improve health outcomes, this may not be the case for every person and under all conditions."

One independent researcher contacted by 番茄社区 for comment was not ready to give up on fitness trackers as a weight-loss aid.

"In my practice, patients using such devices to monitor their activity level and diet appear to be more adherent to prescribed diet/exercise regimens and have greater success with weight loss," said , of the Icahn School of Medicine at Mount Sinai, who was not involved in the study.

"It will be important to note patient characteristics between the standard and technology enhanced groups, as well as their adherence to the prescribed regimens. The fact that both groups had significant improvement in body composition and other parameters is reassuring, and reinforces the importance of using phone and online websites outside of face-to-face meetings to assist with weight loss."

Jakicic, too, emphasized that the study didn't prove that the devices are useless. "We should not send the message that these wearable technologies do not help with weight loss – there were some in our study for whom it made a difference," he said.

The trial included 471 young adults with BMI values of 25.0 to 39.9. During the first 6 months, all participants received the same intervention, which included counseling sessions via phone, text messages, and online study materials, and then were randomized into two groups. The "enhanced intervention" group (n=237) was provided with wearable trackers (BodyMedia FIT Core) to monitor physical activity and diet through a website, while the control group (n=234) was instructed to self-monitor physical activity and diet through a different web-based system. Both groups were instructed to complete 300 minutes of moderate-to-vigorous physical activity per week.

Total weight, body composition, cardiorespiratory fitness, physical activity and diet were measured five times throughout the 24-month trial. Approximately 120 participants were lost to follow-up; however, all but one of the original participants were included in the primary analysis, with missing data assumed to be random.

Although there was no added benefit for the fitness tracker, Jakicic and colleagues noted that both groups did show significant weight loss and improvements in other outcome measures relative to baseline.

The authors emphasize one potential limitation of the effectiveness of the fitness tracker was placement on the upper arm, while most commercial devices are typically worn on the wrist.

Asked about future research on the topic, Jakicic told 番茄社区, "There [is] a lot that we still need to know. For whom and under what circumstances are these types of devices most effective for weight management? How can we keep patients engaged in the use of these devices? Is there an appropriate time when these should be used to improve outcomes? Are there key things that these devices and their corresponding webpage or app do not do that are important for behavior change and weight control? Are these types of devices more effective for prevention of weight gain rather than promoting weight loss? We are interested in all of these areas and hope to pursue them in the near future."

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