It has been long established that watching too much television is linked to childhood obesity. Now a U.S. study is suggesting that this also holds true for smaller screens as well, including smartphones, gaming consoles, tablets, and computers.
According to a researchers’ report in the Journal of Pediatrics, if teens had the habit of watching a minimum of five hours of TV a day, the odds of their being obese soared by 78 percent in comparison to teens who did not have TV time. However, in an age where smartphones are becoming increasingly common, heavy usage of these kinds of screens has been linked to a 43 percent greater risk of obesity. Lead study author Dr. Erica, a public health researcher at Harvard University in Boston states that, “the landscape has changed so quickly with regards to how much we all use mobile screen devices and computers.”
“We have known for years now that spending too much time watching television contributes to a higher risk of developing obesity among kids, mostly because too much TV can lead to an unhealthy diet,” Kenney added via email. “We see similar associations between other screen device use and diet, physical activity, and obesity risks as we’ve seen in the past for TV.”
On examining the influence of how large and small screens played a role in contributing towards obesity, researchers analyzed nationally representative survey data collected in 2013 and 2015 amongst 24,800 adolescents between grades 9 and 12.
Almost 17 percent of youth claimed to have watched no TV during weekdays, while 7.8 percent admitted to watching five or more hours daily. Nearly one in five teens in the study spent approximately five hours a day using smaller screens during the week.
Another aspect of the survey was questioning the teens as to how many sugary drinks they consumed, as well as their height and weight. More than 25 percent of boys and 20 percent of girls stated that they drank at least one soda or a sugar-sweetened drink per day. On top of this, two-thirds of boys and three-quarters of girls said they did not exercise daily.
In review, 14 percent of the teens that were reviewed in the study were obese. Even after adjusting these results for age, sex, race and ethnicity and other time with small screens, TV viewing was associated with particularly higher odds of consuming one or more sugary drinks and therefore, an increased risk of obesity. It was also shown that more time spent with other screens was linked to insufficient sleep, drinking sugary beverages and general inactivity. However, the study was unable to prove without a doubt that television or time spent on smaller screens directly causes obesity.
However, as the authors of the study note, it is very probable that spending excessive time on screens is caused by obesity, inactivity, or fatigue rather than the opposite of such effects being caused by too much time watching TV, or looking at smartphones and tablets. Dr. David Hill, a researcher at the University of North Carolina School of Medicine and chair of the American Academy of Pediatrics Council on Communications and Media, says that some previous research has indicated that TV causes obesity. Subsequently, the research also suggests that those kids who significantly reduced watching television could cut back on their weight.
While the role of other screens has been more ambiguous, at least one study suggests that only passively watching television affects the risk of obesity. Hill (who was not involved in the current study), wrote; “This study helps us understand that the link between obesity and media use may extend to other types of screens.” Hill added that advertisements which teens see for unhealthy foods may be contributing to the problem. Not only this, but sleep deprivation (which is tied to obesity), as well as too much time spent on screens has been known to interfere with the quality and quantity of sleep which teens are getting.
“We encourage parents to work with kids to examine what they need to accomplish in a day to be successful: how much sleep should they get, when they should eat, how much time do they need for homework, exercise, and family activities,” Hill says. “Screen media time should fit around those activities or complement them rather than displacing them.”