Wearable Technology Does Not Improve Weight Loss

Ricki Lewis, PhD

September 20, 2016

The use of wearable technology to track diet and exercise does not improve weight loss, compared with standard advice on physical activity and diet, according to data from a randomized controlled trial.

"The results of the study showed that engaging in a behavioral weight-loss program resulted in significant weight loss over 24 months. However, when we added the technology, it actually hurt the weight loss by about 2.4 to 2.5 kg. So wearing the technology resulted in less weight loss than not wearing the technology," said lead author John M Jakicic, PhD, of the department of health and physical activity, Physical Activity and Weight Management Research Center at the University of Pittsburgh, Pennsylvania, in an author audio interview.

Dr Jakicic and colleagues published the results of the 2-year study in the September 20 issue of the Journal of the American Medical Association.

The use of wearable technology to chart daily steps taken, stairs climbed, calories consumed, and other measurements has soared in recent years. For example, according to the International Data Corporation's Worldwide Quarterly Wearable Device Tracker, 19.7 million devices were shipped during the first quarter of 2016, compared with 11.8 million a year earlier. However, the long-term health benefits associated with their use remains unclear.

Therefore, Dr Jakicic and colleagues assessed the effect of wearing devices for 18 months. The team enrolled 471 participants, aged 18 through 35. At baseline, participants' body mass indexes ranged from 25 to <40.

All participants were instructed to adhere to a low-calorie diet, increase physical activity, and attend weekly counseling group sessions. At 6 months, all participants added a monthly 10-minute telephone call, weekly or twice-weekly text messages to encourage weight-loss behaviors, and access to a study website that offered educational materials. Counseling shifted to monthly after 6 months. The study website offered content from the counseling sessions plus a "weekly behavioral tip."

Also at 6 months, the researchers randomly assigned participants to standard behavioral weight-loss intervention, which included access to a website that enabled self-monitoring of progress but not a wearable device or to standard intervention plus receipt of "technology-enhanced weight-loss intervention," which consisted of a wearable device linked to a website to monitor the data. At the time of the study such devices were worn on the upper arm, rather than the wrist as they are today. The device used was BodyMedia FIT Core.

Overall, participants given the devices lost less weight than those in the standard-intervention arm, with a difference of 2.4 kg (95% confidence interval [CI], 1.0–3.7; P = .002) at 24 months. Specifically, estimated weight loss with the standard intervention was 5.9 kg (95% CI, 5.0–6.8 kg) and 3.5 kg (95% CI, 2.6–4.5 kg) with the enhanced intervention.

Moreover, the difference between the standard vs enhanced intervention groups increased over time.

Difference in Weight Loss Between the Standard- vs Enhanced-Intervention Groups

Time interval, mo Standard intervention (%) Enhanced Intervention (%) P
6 -9.4 -8.4 .15
12 -8.9 -7.0 .01
18 -7.9 -5.6 .002
24 -6.4 -3.6 < .001

Body composition, diet, fitness, and physical activity improved similarly in both groups.

The researchers say the reason for the worse outcomes in the enhanced-intervention group is unclear and warrants further study. "We have to try to understand when and where and how we use these technologies before we implement them broadly across the population," Dr Jakicic said.

Limitations of the study include restriction to young adults, lack of a no-intervention control group, use of now-dated wearable technology, randomization at 6 months rather than at the outset of the study, and self-reporting of diet and physical activity.

Drs Jakicic reports receiving honoraria from Weight Watchers International. Disclosures for the coauthors are listed in the article.

For more diabetes and endocrinology news, follow us on Twitter and on Facebook.

JAMA. 2016;316:1161-1171. Article


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: