Children's brain power is improved if they spend less than two hours a day looking at screens, according to a study.
It can lead to poorer quality sleep, which can harm a child's development. "This study is showing that less than two hours of recreational screen time is beneficial for children".
Researchers discovered, by analysing United States children's data for eight to 11-year-old, the more of the recommendations a child fulfilled, the better their cognition.
Scientists gathered questionnaire data on more than 4,500 kids ages eight to 11 in 20 locations around the U.S. The information was compared to the Canadian 24-Hour Movement Guidelines for Children and Youth, which recommends a minimum of 60 minutes of exercise, a maximum of two hours of screen time, and nine to 11 hours of sleep for this age group.
"Evidence suggests that good sleep and physical activity are associated with improved academic performance, while physical activity is also linked to better reaction time, attention, memory, and inhibition", said Walsh.
Only half of the children met the sleep recommendation, while 63 per cent spent more than two hours watching TV or on devices.
Children spent an average of 3.6 hours a day engaged in recreational screen time. The study's authors said that more research is needed to probe the links between screen time and cognition, including research differentiates between different types of screen time activities and what effects they have on children.
"Based on our findings, paediatricians, parents, educators, and policymakers should promote limiting recreational screen time and prioritising healthy sleep routines throughout childhood and adolescence", he said.
But scientists in Canada found only one in 20 of the 4,520 U.S. children studied were meeting all of these key recommendations.