Cutting back kids' time watching TV and playing video games may not encourage them to spend more of the day running around outside, a new study suggests.
Just four in 10 US kids met dual national guidelines for getting enough physical activity and for limiting "screen time," researchers found - but the likelihood of kids exercising regularly didn't depend on whether they kept away from screens.
"I don't think it's as simple as, if a child is not watching television, then by default that child will be physically active," said the study's lead author, Tala Fakhouri, from the Centers for Disease Control and Prevention.
Guidelines from the National Institutes of Health and the American Academy of Pediatrics call for elementary school-aged kids to get at least one hour of exercise and spend less than two hours in front of screens every day.
How the study was done
The new findings are based on just over 1 200 US children, aged six to 11, whose parents answered questions about their health and behaviour. The survey group was designed to be representative of all kids nationwide in 2009-2010.
Fakhouri and her colleagues found that 70% of kids met the recommendations for daily physical activity and 54% met the screen-time recommendations, according to their parents' reports. 38% met both sets of guidelines.
Hispanic and older children and girls were less likely to get at least an hour of exercise each day than their white, younger and male peers.
Older kids were also less apt to meet screen-time recommendations, as were black youth. However, Hispanic children were more likely than white kids to keep their screen time under two hours daily.
What the study found
Obesity was tied both to not getting enough exercise and to spending too much time in front of TV and computer screens, according to a paper online January 7 in JAMA Pediatrics (formerly Archives of Pediatric and Adolescent Medicine). But otherwise, there was no link between the odds of meeting one recommendation and meeting the other, the researchers said.
According to the CDC, 17% of US kids and teens are obese. Getting kids off the couch and outdoors - as well as improving the nutritional content of meals at home and at school - is considered key to keeping that number from rising further.
But researchers said the new study backs up earlier findings showing too much screen time and not enough exercise may be separate issues that parents and schools need to address independently.
"These results show that we would be wrong in assuming that if school-based and/or community-based programmes to increase children's physical activity are implemented, we would automatically see a reduction in sedentary behaviours (like watching TV)," Tami Benham Deal, who studies kids' physical activity at the University of Wyoming in Laramie, told Reuters Health in an email.
"Similarly, just turning off the TV or computer will not cause children to be more active," added Benham Deal, who wasn't involved in the new research.
Fakhouri said that parents in the study may have overestimated how active their kids are - so the real number of elementary school students getting an hour of exercise daily may be less than 70%. A similar 2003-2004 US study, which used accelerometers to measure kids' activity, found just 42% met the recommendations, she said.
For parents, Benham Deal recommended making family time more physically active and giving kids toys that promote physical activity, rather than inactivity.
"As a parent, I always tried to use screen time as a reward for being physically active and when we watched TV, we would use the commercial breaks as fitness breaks," she added.
(Reuters Health, January 2013)