“There’s even more evidence that fitness trackers don’t work,” declared Time.com last October.
Yikes. The news came from a study of 470 overweight or obese young adults who had lost an average of 18 pounds over six months with a mix of dieting and exercise.1
Over the next 18 months, those who were assigned to use a fitness tracker regained more weight (about 10 pounds) than those who didn’t use a tracker (6 pounds). And the fitness tracker group was no more active than the control group, which reported its activity to a website.
Why? The study’s authors aren’t sure.
People using the trackers may have thought, “Oh, I exercised a lot today. Now I can eat more,” lead author John Jakicic, a professor in the department of health and physical activity at the University of Pittsburgh, told National Public Radio last September.
Or, fitness trackers may inspire some people and discourage others. Or maybe a tracker only helps if you’re cutting calories.
In an earlier study, people who got diet counseling and used a tracker lost more weight than people who just got a weight-loss manual.2 People who got only the tracker or only the counseling did no better than those who got only the manual.
The bottom line
If you use a tracker, don’t toss it yet. Just don’t assume that taking, say, 10,000 steps a day will make the pounds melt away.
And don’t assume that you can celebrate your tracked walks with a chocolate sundae.
1 JAMA 316: 1161, 2016.
2 Int. J. Behav. Nutr. Phys. Act. 8: 41, 2011.
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