WHO gets stern on screens
New recommendations from the World Health Organization say children under the age of two shouldn't have any screen time.
The report outlines the amount of time children under-5 should spend sleeping, sitting and running around.
Letting them play computer games and watch TV or YouTube will increase the chance they grow up sedentary and obese, the WHO says.
Once they're walking, children should spend "at least" three hours doing physical activities each day, with kids aged three and four spending at least an hour in moderate to vigorous exercise, the guidelines state.
But London expert Professor Russell Viner from the Royal College of Paediatrics and Child Health (RCPCH) told Newshub the guidelines weren't helpful and parents should set the rules.
"Some people would like a straight up 'no more than three hours' or 'no more than two hours', and bam, that's done. However let's be clear, that's never going to work."
Research from the RCPCH had found only weak evidence for a time limit on screens, but good support that they should be avoided one hour before bedtime.
University of London cognitive psychology reader Dr Tim Smith told the BBC the guidelines only further confused existing conflicting recommendations, including those from the RCPCH, that had "bombarded" parents in recent months.
"While the report makes a potentially helpful step in distinguishing sedentary screen time from active screen-based games, where physical activity is required, this remains an oversimplification of the many ways young children and their families engage with screen media," he said.
New Zealand's Ministry of Health discourages screen time for under-two-year-olds and recommends limiting screen time to less than one hour a day for children aged two years and older.
The full report is available on Scimex.