(NEW YORK) — The amount of time that young people spend watching screens — instead of physical activity like sports, hikes or gardening — could be linked to health issues in adulthood, according to a new study.
Children and teenagers who spent more time watching television had less efficient oxygen use during exercise, higher blood pressure, and higher rates of obesity in mid-adulthood, even when accounting for sex, childhood body mass index and the family’s economic situation, the study published in Pediatrics says.
The researchers started tracking hundreds of children in New Zealand in 1973 and followed them until they turned 45 years old.
The study can’t prove that watching TV caused those health effects, says study author Dr. Bob Hancox. But there are possible reasons the two could be linked, he says. Kids who have more screen time might do less physical activity, because of the sedentary activity of sitting down and watching TV. They may also have poorer eating habits, due to seeing ads for junk foods, Hancox says.
“If you’re sitting watching TV, you’re not being active and therefore that increases your risk of being overweight and being less fit,” Hancox says.
The study started in the 1970s, when there were fewer screen time options than today. But experts say the findings still offer important information for how parents can guide screen time usage today.
“This really highlights the importance of critical development years. To emphasize – from a structural societal level, systems level, the need to set up programs, schooling, and support to allow parents to be successful in helping their children be more physically active,” says Dr. Veronica Johnson, an assistant professor of internal medicine and pediatrics focusing on obesity medicine at Northwestern Medicine.
Parents should pay close attention to children’s screen time, experts say. The American Academy of Pediatrics said that parents should limit unnecessary screen time, view screens with their child, and focus on content and communication around screen time to help children’s emotional, social, brain and identity development.
“Screen time is inevitable,” says Johnson. “It’s important to set some guidelines or expectations for your children as far as when you should be using the screens and how the screens should be utilized.”
Parents can also focus on the factors associated with screen time that could lead to problems later on, like diet and physical activity. The CDC recommends drinking water with fruit instead of sugary drinks, slicing up vegetables to use as quick snacks, and flavoring your meals with lemon juice, herbs, or no-salt spice blends instead of salt. The USDA’s MyPlate has recommendations for every age and activity level.
“Finding a meal plan that works for the individual is very personalized,” says Dr. Amanda Velazquez, director of obesity medicine at Cedars-Sinai. The best diet plan is the one that fits in with someone’s schedule, cultural preferences, and eating patterns — because that’s what they’ll be able to stick to, she says.
Families can increase their level of physical activity by spending time in parks, experts say, or incorporating activity into daily tasks. “Instead of driving, a parent can walk with their child to school or commute to work by foot. Some communities have sidewalks,” says Dr. Louis Aronne, director of the Center of Weight Management and Metabolic Clinical Research at Weill-Cornell Medical College, “Anything besides sitting on the couch or sitting in a room watching a screen.”
With screens involved in all parts of our lives, screen time does not always have to be a bad thing for children, experts say. Developmentally appropriate educational programs, talking to family over video chat and exercise videos have benefits for families.
“Watching something with high-quality educational content that is engaging or FaceTiming with grandparents is going to have a different level of engagement and stimulation versus passively watching television shows in the background,” says Velazquez.
Screens have also evolved over time, from having two channels that did not have 24-hour programming to now we have many different screens at all times of the day, Hancox says. “It’s the dose that makes a difference. The dose of TV and screen time we’re having at the moment, from a physical health and probably mental health point of view is clearly a bad thing when we’re doing too much.”
Barrington Hwang, M.D., is a child and adolescent psychiatry fellow at Vanderbilt University Medical Center in Nashville, Tennessee, and a member of the ABC News Medical Unit.
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