For each additional hour of television that a teen watches, on average, the more likely they are to have too much sugar and caffeine, according to a new study.
The study, done by researchers at McMaster University and California State University – Fullerton, examined the relationship between the time spent on electronic devices and the amount of sugary soft drinks and energy drinks that U.S. children in grades 8 and 10 consumed.
The researchers found that in their sample of 32,418 teens, they actually drank a bit less pop and energy drink than in 2013, and the amount of time they spent on screens stayed about the same.
But they also found that the more time teens spent using an electronic device, the more likely they were to exceed the World Health Organization’s recommended sugar intake. They were also more likely to exceed the recommended intake of caffeine.
Each hour of watching TV is associated with an additional seven grams of sugar intake from soda or energy drinks, the researchers found.
“It isn’t a huge amount,” said Dr. Katherine Morrison, a professor at McMaster’s department of pediatrics and co-author of the study, published this week in the journal PLOS ONE. “I think what struck me was the likelihood of exceeding daily added sugar just from these beverages was increased by a third. And that was concerning for me.”
Watching television seemed to be particularly bad: an additional hour of watching TV was linked to a 32 per cent increased risk of exceeding the sugar guidelines, which suggests that added sugar should be limited to 10 per cent of total daily calorie intake.
Morrison can’t quite say why, but it might be linked to the idea of “distracted eating,” she said.
“There’s been other papers that have sort of suggested in adults that television viewing is associated with more distracted consumption of sugary beverages and perhaps food in general,” she said.
Michelle Guerrero, a postdoctoral researcher at the CHEO Research Institute at the Children’s Hospital of Eastern Ontario in Ottawa, also thinks mindless eating is likely a contributor.
“When we’re in front of the television, we’re not paying attention to how many snacks we’re having, especially if we have a bowl of popcorn or a bag of chips.”
Another reason could be advertising, she said.
“Is it this advertising for ‘unhealthy foods’ that are making us more tempted to engage in snacking and drinking sugary beverages? We’re not exactly sure.”
While she cautions that this study, like most studies on screen time, relies on self-reported data, excessive screen time more generally is linked to a whole host of negative health outcomes, she said.
People who use screens for less than two hours per day, the current recommendation, are more likely to have better body composition, lower cardio-metabolic risk scores, favourable psychological well-being, higher global cognitive scores and lower impulsivity, she said.
Increased sugar and caffeine intake can lead to problems too, Morrison said.
“Simple sugars are not awesome from a health perspective.”
“And the excess caffeine, it can impact sleep, and it impacts concentration abilities.”
While she thinks there might be an increased risk of obesity with excessive sugar intake, she thinks that the sleep disruption caused by too much caffeine is also a very serious risk. “Your sleep health impacts all kinds of things, including how you do at school and how you interact with your family and your more common day-to-day activities than just the fact that you may put weight on.”
Parents who are concerned about their children’s sugar and caffeine intake should consider keeping soft drinks and energy drinks out of the house, she said.
“Then it’s water that’s in the fridge, or milk, when they feel they want to drink something while they’re watching TV.”
And while older teens can and do buy junk food for themselves outside the home, not having it in the kitchen will make a difference, she thinks.
“Watching television is something they mostly do at home,” she said, so not having these around will help.
Guerrero suggests also setting limits on children’s screen time. “No devices in a child’s bedroom, that’s one strategy,” she said.