Letting a toddler spend lots of time using screens may delay their development of skills such as language and sociability, according to a large Canadian study.

Axar.az reports citing BBC.

The research, which tracked nearly 2,500 two-year-olds, is the latest piece of evidence in the debate about how much screen time is safe for kids.

In Canada and the US, experts say children should not use screens before they are at least 18 months old.

But UK guidelines set no such limit.

The Royal College of Paediatrics and Child Health says there is not enough evidence, even when you include this new study, for a "direct toxic effect".

Mums were surveyed (between 2011 and 2016) about screen use, and filled out questionnaires about their child's skills and development at ages two, three and five.

Screen time included watching TV programmes, films or videos, gaming, and using a computer, tablet, phone or any other screen-based device.

At the age of two, the children were clocking up around 17 hours of screen time per week.

This increased to around 25 hours a week by the age of three but dropped to around 11 hours a week at the age of five, when the children started primary school.

The findings, published in the JAMA Paediatrics, suggest increased viewing begins before any delay in development can be seen, rather than children with poor developmental performance then going on to have more screen time.

But it is not clear whether screen time - including how much or what type - is directly to blame. Screen use might just go hand-in-hand with other things linked to delayed development, such as upbringing and how a child's remaining leisure time is spent.