Smartphones Alone Don’t Help Teens Lose Weight, Study Finds


While many teens use their smartphones almost constantly, the omnipresent gadgets are not an effective tool for losing weight among this demographic, a new study shows.

Led by assistant professor Chad Jensen, a team of researchers from Brigham Young University’s psychology department tracked 16 overweight or obese teens for a total of 24 weeks, studying how effective device-driven interventions were at keeping off weight.

“We know that teens are on their phones, which gives us a way to intervene in the moment,” said Jensen, the study’s lead author. “We wanted to determine whether we could effectively use texting and a commercially-available smartphone app to help adolescents with weight loss.”

The researchers divided the 24-week segment into two parts – the first 12 weeks involved smartphone and weekly in-person consultations, and the second segment involved only smartphone-provided interventions, including text messages sent by the research team as a reminder to stay on track.

During both parts of the study, the smartphone intervention included the Daily Burn app, which provides online fitness classes and other health tools, such as a nutrition tracker.

A key element that the researchers were studying was the amount of self-monitoring that the teens reported during both in-person and phone-only intervention periods.

“We know that self-monitoring is really important for weight control as it helps people be mindful about the foods they’re eating, but very few teens do it because it’s so laborious,” Jensen said. “Smartphones were extremely helpful because they made self-monitoring more efficient – it’s much easier to scan a barcode than it is to track every calorie with paper and pen.”

However, the study found that teens were less likely to self-monitor during the period without weekly in-person meetings. In fact, while teens self-monitored about 50 percent of the days over the course of the period with in-person interventions, they did so less than 17 percent of the time during the smartphone-only period. In addition, they gained back much of the weight they’d lost.

“The Daily Burn app doesn’t include all the things we know are successful for weight control, like social support and the accountability that comes with that support,” Jensen said. “That support existed when the teens were meeting with other teens and sharing their experiences. And that was taken away.”

The social aspect of in-person meetings appears to play an important role in weight loss – at least among adolescents.

“You can’t totally replace in-person social networks with virtual networks,” Jensen said. “But I think one of the future directions of mobile health technology is figuring out how to take advantage of people’s naturally-occurring social networks and using family and friends to fill the role that meeting with a clinician would normally fill.”

Jensen and his team concluded that “smartphones likely hold promise as a component of adolescent weight control interventions” but may require additional elements that would make a weight-loss program effective, such as social support.

For example, a majority of teens – 73 percent – found the text messages they received during the smartphone-only intervention period a positive step. “Several participants noted that the text messages were ‘enthusiastic’ and ‘uplifting,’” and served as an effective way to remind the teens that they were doing a good job.