If you’ve been wearing a fitness tracker for a while and have been disappointed in the results you’ve received, you’re not alone. A new study published in the Journal of the American Medical Association indicates that fitness trackers could be impeding your ability to meet your weight loss goals.

The study, which took place between 2010 and 2014, included 471 randomized participants (74.5% completed the study) which were separated into two main groups. One group manually documented their physical activity at the end of the day while the other one wore automatic activity trackers which did the documentation for them.

Participants that completed the study participated for a period of two years, initially being put on a low-calorie diet and encouraged by the researchers at the University of Pittsburgh’s Physical Activity and Weight Management Center  to maintain an active lifestyle.

The results of the study were surprising. The group that used electronic fitness trackers to automatically log their activities lost less weight than the group that logged their activity manually.

From the study’s summary:

Among young adults with a BMI between 25 and less than 40, the addition of a wearable technology device to a standard behavioral intervention resulted in less weight loss over 24 months. Devices that monitor and provide feedback on physical activity may not offer an advantage over standard behavioral weight loss approaches.

These fitness trackers monitor different activities such as footsteps and log this data in a way that the participant can review. One possible explanation for the results would be that seeing exactly how active you are, while encouraging that activity, may justify extra caloric intake to the participant.

Simply put: You can’t outrun a bad diet.

Allure reached out to Fitbit, a leading company in the category of electronic fitness tracking devices including wearables, electronic scales, and more. Fitbit’s response included the following:

The University of Pittsburgh study published in JAMA did not use Fitbit devices or the Fitbit app, so we cannot speak to their specific findings. As the leader in the wearables category, we are confident in the positive results users have seen from the Fitbit platform, including our wearable devices, Aria wifi smart scale, and Fitbit app.

Fitness trackers are being used in wider studies

Fitbit also added that its devices are currently being used in over 200 studies, concentrating on a wider range of results including basic physical activity, lifestyle behaviors, health metrics, and more.

Fitness trackers are being used by an extraordinary number of people. We here at ReadWrite have even done our own non-scientific anecdotal experiments with fitness trackers and healthy eating that have offered positive results. People are losing weight with fitness trackers.

Where things get a bit confusing is when we use them as a crutch for healthy habits elsewhere. Both of the parties in this study lost weight. Neither of the groups gained or maintained their original weight levels. While one group lost a little bit more, the study ultimately found that, “Both groups had significant improvements in body composition, fitness, physical activity, and diet, with no significant difference between groups.”