A new study suggests FitBits may not do much to help weight loss.

In fact, the study found that among overweight or obese young adults, the addition of a wearable technology device (that provided feedback on physical activity) to a standard weight loss intervention resulted in less weight loss over 24 months.

There are a lot of devices out there designed to monitor physical activity and diet with the goal of assisting weight loss, but as waistlines continue to bulge, getting data on the effectiveness of such technologies becomes more important.

Nearly 500 students were involved in a two-year study in the US. They were split into one group that received a standard behavioural weight loss intervention, and another with technology-enhanced weight loss intervention.

Participants were placed on a low-calorie diet, prescribed increases in physical activity, and had group counselling sessions. After 6 months they all received telephone counselling sessions, text message prompts, and access to study materials on a website.

At the same time, those in the standard intervention group began self-monitoring their diet and physical activity using a website, and those randomly assigned to the enhanced intervention group were provided with a wearable device (like a FitBit) and accompanying web interface to monitor diet and physical activity.

Seventy-five percent of participants completed the study. The researchers found that the average weights for the enhanced intervention group dropped by about 3.5kg, while the standard intervention group lost an average of 5.9kg.

That means that after 24 months, the standard intervention group lost about 2.4kg more than the enhanced intervention group.

The researchers note that both groups had significant improvements in body composition, fitness, physical activity, and diet, with no significant difference between groups.

They add that the reason for the difference in weight loss between the groups warrants further investigation.