A new study claims those wearable fitness trackers that have gotten so popular in recent years may be entirely useless when it comes to losing weight. A new study found that young adults on a healthy diet and exercise program over a long period didn’t see any benefits at all from having a wearable device, and in fact showed worse results compared to those who did not use them, according to a statement from the University of Pittsburgh School of Education.

The study involved examining people who wore the devices for 24 months compared to those who did not. They found that those wearing fitness trackers lost 2.4 kilograms less than a group in a program that tracked their progress via a website. This was based on 471 adults between the ages of 18 and 35 who were at least overweight and up to moderately obese.

The participants self-reported how many calories they were consuming, and exercised 100 to 300 minutes per week, either moderately or vigorously, depending on the individual. After two years, those with a wearable device lost just 3.5 kilograms on average compared to those without, who lost 5.9 kilograms.

“While usage of wearable devices is currently a popular method to track physical activity—steps taken per day or calories burned during a workout—our findings show that adding them to behavioral counseling for weight loss that includes physical activity and reduced calorie intake does not improve weight loss or physical activity engagement. Therefore, within this context, these devices should not be relied upon as tools for weight management in place of effective behavioral counseling for physical activity and diet,” said John Jakicic, the study’s lead researcher and chair of Pitt’s Department of Health and Physical Activity.