As I reported here in November, a study in the journal JAMA Pediatrics found that when children and teens have smartphones and tablets in their bedrooms — even if the devices are not in use — the quality and quantity of their sleep deteriorates significantly, causing them to be drowsy and fatigued during daytime hours.
Well, a new study, published this month in Global Pediatric Health, not only supports those earlier findings, but also found another possible troubling effect of letting electronic devices into a child’s bedroom at night: Young people who spend time in front of a “screen” at bedtime — specifically a smartphone or TV — are more likely to be overweight or obese.
The study’s authors hypothesize that it’s because tired children tend to skip breakfast. To sate their hunger later in the day, they may then turn to high-calorie foods.
That can lead to a kind of vicious cycle.
“We saw technology before bed being associated with less sleep and higher BMIs [body mass indexes],” said Caitlyn Fuller, the study’s lead author and a medical student at Pennsylvania State University, in a released statement. “We also saw this technology use being associated with more fatigue in the morning, which circling back, is another risk factor for higher BMIs. So we’re seeing a loop pattern forming.”
As Fuller and her Penn State colleagues point out in their study, other research shows that at least 40 percent of children in the United States have cell phones by fifth grade. Yet little is known about the health effects of that technology on those children.
For the study, the researchers asked the parents of 207 children aged 8 to 17 to complete a detailed questionnaire. The families were recruited from two clinics at Penn State, including an obesity clinic. Ninety-three of the children had a “normal” BMI, while 24 were classified as “overweight,” 35 as “obese” and 55 as “severely obese.”
The parents were asked about the types of “screen” technology their children used (smartphones, computer, television or video game consoles), the frequency with which they used it and when they used it. They also answered questions about their children’s sleep habits and whether they were tired in the morning and/or ate breakfast.
An analysis of all that data revealed that children and teens who watched television or played video games at bedtime averaged 30 minutes less of sleep each night than those who did not. The kids playing video games also reported having more trouble staying asleep.
Children and teens who used their phones or computers at bedtime slept even less — by an average of about 60 minutes per night.
Given those findings, it’s not surprising that the use of smartphones, computers and video games at bedtime was associated with children being more tired in the morning. Using those devices — as well as watching television — also significantly increased the odds that a child would skip breakfast.
Finally, the analysis found that young people who watched television or who used their phones at bedtime were more than twice as likely to be overweight or obese than those who did not. No such association was found between bedtime video game or computer use and weight, however.
Limitation and implications
This study comes with plenty of caveats. Most notably, it’s an observational study and therefore can’t prove that the use of electronic devices at bedtime directly caused the children to have difficulty with sleeping or with maintaining a healthy weight. Furthermore, the data came from questionnaires filled out by the children’s parents — data that are subjected to the parents’ faulty memories or biases. And the number of children in the study was small.
There is also that confusing finding that television and smartphone use at bedtime is linked with an increased risk of an unhealthful weight, but not the use of computers or video games, even though those devices were also associated with a reduction in the quantity and quality of children’s sleep.
Still, the study’s findings are in line with a growing body of research — like last month’s JAMA Pediatrics study — that is raising concern about the harmful influences that new technology are having on children’s health.
“Along with all of the benefits of technology… come repercussions,” Fuller and her colleagues write in their paper. “It is important to be aware of how this new age of technology may influence the coming generations so that we may be prepared to offer recommendations to prevent the harmful effects of overexposure.”
What parents can do
For children younger than 18 months, avoid use of screen media other than video-chatting. Parents of children 18 to 24 months of age who want to introduce digital media should choose high-quality programming, and watch it with their children to help them understand what they’re seeing.
For children ages 2 to 5 years, limit screen use to 1 hour per day of high-quality programs. Parents should co-view media with children to help them understand what they are seeing and apply it to the world around them.new
For children ages 6 and older, place consistent limits on the time spent using media, and the types of media, and make sure media does not take the place of adequate sleep, physical activity and other behaviors essential to health.
Designate media-free times together, such as dinner or driving, as well as media-free locations at home, such as bedrooms.
Have ongoing communication about online citizenship and safety, including treating others with respect online and offline.
FMI: The new study can be read in full on the Global Pediatric Health’s website.