Screen time: Questions on physical health

How many hours in a day is too long to use a digital device? The short answer is whenever, as a parent, you think is too long, but experts generally agree on a few conclusions. Screens should be off limits to children under 2. Although the American Academy of Pediatrics says “entertainment” screen time should be limited to just two hours a day, Common Sense Media quashes fears of zombie children: “The reality is that most families will go through periods of heavy and light media use, but so long as there’s a balance, kids should be just fine.”

How does screen time affect weight? Screen time is a sedentary activity. At least one study finds a greater risk for children who watch TV: As reported in the Los Angeles Times, “Compared to the kids who watched less than an hour of TV per day, those who watched an hour or more were 39% more likely to become overweight between kindergarten and first grade. They also were 86% more likely to become obese during that time.”

What about eyesight? Screen time was among the factors blamed in a recent European study that showed increased shortsightedness in people age 25-29 when compared with adults 55 to 59. Again, experts say balance is key: When children have normal outside playtime, adverse effects are minimized.

What is the effect on sleep? A nearly universal recommendation is to keep screens out of the bedroom, primarily to protect sleep. In a recent report, AAP said that screens in the bedroom “delays sleep onset; shortens sleep duration and interferes with achieving deep, restful sleep.” Lack of sleep is associated with obesity and poor academic performance.