ENGLAND — The UK government released guidance recommending that children under five be limited to one hour of screen time per day. The guidance advises that children under two should not watch screens alone.

The guidance recommends parents steer clear of fast-paced videos and use screens together where possible. It suggests taking screens away to read stories together or play simple games at mealtimes. The recommendations cover all types of screen use, including computers, tablets, mobile phones, and televisions.

Dame Rachel de Souza, Children's Commissioner for England, and Professor Russell Viner, Department for Education scientific adviser, reviewed the latest evidence and found that long periods spent on screens alone can affect children's sleep and physical activity, which are key to their development. About 98% of children watch screens on a daily basis by the age of two, according to the government statement.

"This is still quite an unknown area in lots of respects and we've taken a precautionary approach," Education Secretary Bridget Phillipson said. This is the first evidence-backed, practical advice issued by the government on screen time for under-fives.

The guidance notes that watching screens with an engaged adult is linked to better cognitive development than solo screen use. It recommends that parents lead by example because children will copy their screen use habits and encourages parents to be present with their children during screen use.

Researchers at the Institute for the Science of Early Years at the University of East London have been studying the content watched by under-fives by observing a three-year-old's brain activity using a sensory cap. Content aimed at children has become faster-paced with more movement and talking over the past 20 to 30 years compared to earlier slower-paced programming, according to the researchers.

"Of course, this isn't actually useful anymore, because this is happening when children are sat still on a chair watching screen content," said Sam Wass, Professor of the Science of Early Years at the University of East London. According to Wass, screens are not as effective as face-to-face learning.

The researchers say there is good evidence of a link between emotional dysregulation and the amount of time spent watching fast-paced, unpredictable content. The guidance also recommends avoiding artificial intelligence toys or tools.

The guidance states that time limits should not apply in the same way to screen-based assistive technologies used to support children with special educational needs and disabilities. The Montastier family in Manchester tried to cut back on their screen time for a week ahead of the guidance being published.