Pre-school and school-aged children who spent more time watching television got less sleep according to a study published in JAMA Pediatrics.

Sleep is important and prior research has suggested that television viewing can cause irregular sleep habits. The American Academy of Pediatrics recommended in 2009 that children under 2 years avoid exposure to any media and that for older children time be limited to one to two hours per day.

The authors examined the association between hours of television viewing and sleep in 1,713 children in Spain through parent-reported sleep duration.

Children who watched TV for 1.5 hours or more a day had shorter sleep duration at baseline. Children who reported increased TV viewing over time (from less than 1.5 hours per day to 1.5 or more hours per day) reported a reduction in sleep at follow-up visits.

"Further prospective studies are required to confirm these findings and to investigate the mechanisms that may underline the possible association."