Ooh, the Fitbit. I'm completely addicted to mine. Thanks to my Fitbit, I've discovered I'm a bit of a sloth on nonexercise days. So now I'm the first person in my house to offer to run upstairs and grab whatever anyone needs. More steps!

I say the Fitbit-and other wearable trackers-are so worth it because they make you aware of your activity level (or lack thereof) and motivate you to move more.

There's science to back me up, too: research shows that tracking your activity and/or being motivated to work out helps shed pounds.

Better yet, one study showed that simply wearing a tracker could help you lose as much weight as if you regularly attended in-person weight-loss sessions.

But if you take the calorie-burn number too literally you could end up gaining weight. How is this possible?

"Most commercial trackers adjust your daily calorie intake based on the amount of activity you have done. For example, if you burn 300 calories on a walk, the tracker will tell you you can eat back 300 calories. Bad idea!" warns Jean Harvey, Ph.D., R.D., professor and chair of the Department of Nutrition and Food Sciences at the University of Vermont.

If you're trying to slim down, eating your exercise calories will slow you down or stop any weight-loss progress.

Another potential pitfall: the built-in 10,000-steps recommendation isn't for weight loss. "[It's] a health recommendation," says nutrition consultant Christopher Mohr, Ph.D., R.D. "Research shows if you log 10,000 steps a day, you'll be healthier." Depending on your current activity level, this target may not be enough to shed pounds.

The Bottom Line

Use your tracker to motivate you to move more. If you're trying to slim down, ignore your tracker's calorie burn. It's likely inflated by exercise above what you need to lose weight.

Send your nutrition questions to Nutrition Editor Brierley Wright, M.S., R.D., at