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That Fitness Tracker Might Actually Make Losing Weight Harder

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Activity monitors are supposed to help us reach our fitness goals, but when it comes to staying motivated, you might want to look beyond your wrist.

In a study published in JAMA on Tuesday, researchers found that fitness trackers weren’t the boon to longterm weight loss they expected them to be, with users dropping far fewer pounds than those tasking with manually tracking their activity after two years.

In the first stage of the study, 471 overweight volunteers followed a conventional weight loss plan (including a low-calorie diet and an exercise log) for six months. Then, they were split into two groups, with half of the participants getting activity monitors and the other half asked to log their activity online. From The New York Times:

After 18 months — and two years after the beginning of the study — all of the volunteers returned to the lab to repeat their measurements from the start.

Most were thinner now than at the start of the study (although many had regained some of the weight that they had lost during the first six months).

Those who had not worn activity monitors were, on average, about 13 pounds lighter now than two years ago.

Those who had worn the monitors, however, weighed only about 8 pounds less than at the start.


“We were definitely surprised,”Dr. John Jakicic, the study’s lead author, told the Times.

While Jakicic has several theories to explain why the monitor wearers not only weighed more but exercised less, he—as one might expect—urged that further research would be needed to determine precisely how fitness trackers affect motivation.


“We’ve found that questions remain regarding the effectiveness of wearable devices,” said Jakicic in a statement, “and how to best use them to modify physical activity and diet behaviors in adults seeking weight loss.”

[New York Times]