Cell Phone Use May Be Linked to Teen Obesity, Study Suggests

Research shows that too much screen time can cause behavioral and emotional problems in children. A new report abstracted in Current Developments in Nutrition now adds dietary problems to that list.

According to a report out of South Korea, there may be a connection between excessive cell phone usage and obesity in teens. Though more research is needed, the study notes that junk food consumption, eating without thinking, and even digital advertising might all be contributing to the issue.

What Teens Are Saying

Over 53,000 Korean middle school and high school students, ages 12 to 18 years old, completed the Korea Youth Risk Behavior Web-Based Survey 2017. By answering questions, the youth provided data on their cell phone usage. They gave input on several topics, including the amount of time they used their phones.

Teens and preteens also detailed their cell phone activity, such as whether they were searching for information online, watching music videos, chatting, or on social media. They also noted their height, weight, and dietary intake information. 

Researchers gathered the data received from the self-reported survey. They presented their results at the American Society for Nutrition‘s Nutrition Live 2021 meeting. According to their findings, even modest cell phone usage can impact diet and obesity. 

“We observed that adolescents who used (their) smartphone for longer than two hours per day were more likely to have obesogenic dietary behaviors—high intakes of instant noodles, fast-food, chips/crackers, and carbonated and non-carbonated sugar-sweetened beverages; and low intakes of fruit and vegetables—compared with those who used less than two hours per day,” explains Hannah Oh, ScD, assistant professor at Korea University and senior author of the study.

What the kids were doing on their cell phones also mattered

When viewing content related to social networks, playing games, or watching videos/listening to music, those activities were more closely aligned with unhealthy food choices.

Other studies have previously found that screen time is harmful for children. This study is different, with its focus on cell phones and eating behaviors. The full results have not yet been published in a peer-reviewed journal.

Although it's a rigorous study, the findings don’t provide concrete proof that cell phone screen time itself leads to obesity. Further testing is needed to confirm the results.

“The study found a strong association between how much time kids spent on screens and obesity. The problem is that this can’t really be extrapolated into a cause-and-effect relationship, despite the size and the quality of the study. The study was designed as an observation of things that happen coincidentally,” states David Seres, MD, director of medical nutrition and associate professor of medicine at the Institute of Human Nutrition, Columbia University Irving Medical Center.

Dr. Oh agrees, noting that additional research is needed to confirm actual physical body changes and weight increase aligning with cell phone usage. These preliminary findings do, however, highlight potential issues with screen time usage and foods consumed during those times.

Attention Absorbed By Cell Phone Screens

Snacking and “mindless eating” can be easier to do in front of a screen. Not paying attention to what they’re eating or how much of it they’re taking in can lead to weight gain and unhealthy food choices for teens. Skipping meals because they are engrossed in phone activity is also problematic.

Food marketing may also contribute to dietary options that result in weight gain. Between social media and streaming video or music content, advertising pours into teens’ sights. Seeing the food on screen can lead to an immediate craving. The advertising can also be misleading, sometimes
delivering messages about a food being healthy that really isn’t.

Poor sleep quality and just not getting enough rest were also problems noted with prolonged cell phone usage.

“Short sleep is known to increase appetite—increase hunger and decrease satiety—by altering levels of appetite-regulating hormones,” states Seaun Ryu, BA, a master’s student at Korea University and first author of the study.

Much of the negative impact the participants suffered mirrors the effects on kids who have too much screen time in ways other than in front of the phone. In fact, the American Academy of Child & Adolescent Psychiatry notes that weight problems, mood problems, sleep problems, and body
image issues can all be results of too much screen time.

Helpful Options

If kids have cell phones, they’re going to use them. The hope is that they can use them constructively, and not create habits that have a detrimental impact on their health. While it’s not possible to monitor what they eat while using their cell phones all the time, there are practices that can be helpful. 

Focusing more on food and making healthy choices, as opposed to focusing on weight, is a good place to start. Having options for them to be active and enjoy other activities is another. Looking at why they’re making certain dietary selections, and offering healthy alternatives, is also important. Even putting the phone to positive use, and checking out available nutrition apps, is an option.

Providing a positive example also makes a huge difference.

“Kids and teens pick up a lot from the adults around them, and relationship with food and body is no exception,” states Willow Jarosh, MS, RD, owner of Willow Jarosh Culinary Nutrition. 

Jarosh notes that the concern should be less about obesity and more about what is healthy for each person. 

Whether dealing with food choices while on the cell phone or in front of the television, helping children make healthy choices now can help them make informed healthy choices later.