Technology falls short in long-term success for dieters
Using tracker wasn’t the right fit for weight loss
The headlines last week jolted the public with the baffling results: “Activity trackers may undermine weight loss efforts.” “Wearable activity trackers may not boost weight loss.” “Fitness trackers didn’t help people lose weight.”
But don’t ditch those devices just yet.
Each of these stories carried photos of people wearing activity trackers on their wrists — which were not the kind used in the University of Pittsburgh study published last week in the Journal of the American Medical Association that tested if an activity tracker device could help with weight loss.
While it’s true that those who didn’t wear an activity tracker over the course of the study lost more weight than those who did, the reasons are not so simple. And the device used in the study might not be comparable to newer devices, such as a Fitbit, now worn on the wrist.
The study was a test of technology that raises more questions about how to keep people on track with weight loss over the long term, said John Jakicic, chair of Pitt’s School of Education’s Department of Health and Physical Activity, who led the study.
With an assortment of helpful strategies — from advice on nutrition and exercise to bariatric surgery — many people can lose weight. But keeping the weight off can be the bigger challenge.
“People can do anything for three months,” he said. “The question is how to keep it off.”
Researchers followed 470 young adults with conditions from overweight to obesity. At the end of two years, people who used an activity tracker lost less weight than a similar group maintaining their weight loss with standard behaviorchange methods.
Study participants started out as one group (body mass index of 25 to less than 40; ages 18-25; 77 percent women; 71 percent white). After all had six months of low-calorie diets, prescribed increased activity and counseling, they were divided into two similar groups. All continued regular contact with intervention staff, but only one group also got a wearable device worn on the upper arm — FIT Core made by BodyMedia — to monitor diet and physical activity. The group with standard intervention only still reported their dietary intake to staff on a website, but the “enhanced” intervention group used the armband device to register their intake.
The device displayed energy expenditure and physical activity for those participants, also available for staff monitoring through the web.
Weight data was complete for 74.5 percent of the participants after two years — 33 people in each
group missed the last weighin; others dropped out for various reasons, including 29 pregnancies. The activitytracker group had a mean weight loss of about 7.7 pounds; the standard intervention group had a mean loss of about 13 pounds.
Even though the tracker did not seem to help with weight loss, Mayo Clinic bariatric psychologist Karen Grothe praised the Pitt research.
“It’s a great study and raises a lot of good questions of the nuances about incorporating technology in lifestyle intervention.” She said she sees potential in further research comparing shortterm and long-term technology use and seeing if passive or active engagement by a user makes more of a difference.
The duration of the study’s two-year intervention might be a factor in the results, she said. “Does the novelty wear off?” She said computer and cell phone apps are often popular at first, until the newness fades.
She said an activity tracker is a more passive form of technology, as well, and that might affect results.
“If you’re doing a food diary or an activity diary, you’re more active.” A study might look into a more active technology and its effect on behavioral change, she said.
“[Participants] might feel like by wearing the monitors they’re making some effort toward change, but it’s quite passive, not enough. They need to say, ‘I need to do more activity today.’ ”
Keeping technology fresh seems to drive leading companies, she said. “Apple and iPhones are incredibly successful. … There are always new iterations. Maybe that’s what keeps people engaged in technology. As technology becomes more sophisticated, it has additional capabilities.” In contrast a technical device that hasn’t changed over two years might not keep a user’s interest, said Ms. Grothe, who has a Ph.D. in clinical psychology with an emphasis in health psychology.
“I wonder if this group of young adults has the expectation that if I have this technology, will it keep advancing?”
The study emphasized it’s important to examine effective weight-loss strategies for the young adult age group because it is in the transition from youth to middle-age adulthood that weight gain develops into obesity.
Mr. Jakicic, who has a Ph.D. in exercise physiology, said there may be several reasons the tracker is linked to less successful weight loss:
“You give someone trying to lose weight advice to watch your diet and get more active. Then you give them a device. … Maybe that de-emphasizes some of the other pieces, and they pay less attention.”
Or, he said, a person might think, “This device tells me I’m doing well with my activity; I can get away with eating more.”
That can also work in reverse if activity is low, he said.
“Instead of motivating them to be more active, they think, ‘I’m a failure.’ ”
Although the data showed similar diet and activity behavior in both groups, the group with more weight loss may have been eating less and being more active, Mr. Jakicic said, “We couldn’t detect it. But we need better measures.”
The study cited limitations, including its results can’t be applied to other age groups, and the device might not be comparable to those worn on the wrist. Also, there may have been issues with how participants used the devices. Self-reported food and drink intake is considered an unreliable method, so measuring energy balance (calories taken in vs. calories expended) is affected. Mr. Jakicic said. “The whole premise of these devices is they tell you what you’re doing. We didn’t think about those other things until we looked at these results.”
Ms. Grothe said testing new devices is worthwhile.
“My hope is that technology will keep advancing to the point where there will be increased accuracy and increased individualization to help people make lifestyle changes.”
The Pitt group is involved in other studies, including testing the use of activity trackers for patients after bariatric surgery.
Mr. Jakicic cautioned people to not take the results of the recent study the wrong way:
“The bottom line is — what we want to tell people — if you have an activity tracker, we’re not telling you not to use it. If you’re planning to get one, we’re not telling you not to buy it,” he said. “But just because you have this, it’s not going to take weight off. A healthy lifestyle, good sleep habits, stress management … pay attention to those other things.”