(CNN) There is little evidence that screen time is in itself harmful to a child's health, says new guidance published by British pediatricians, which avoids setting limits on screen time use for children of all ages.

The guidance, released by the Royal College of Paediatrics and Child Health (RCPCH) in the UK, says it is impossible to recommend age appropriate time limits, but does, however, recommend avoiding screens an hour before bedtime to help children sleep better, according to a press statement.

The report suggests families place value on positive activities such as exercise, socializing and sleep as when these are replaced by screen time, a child's wellbeing is affected.

To date, screen time has been linked to obesity, mental health problems, heart disease and educational failure, but "the evidence base for a direct 'toxic' effect has always been contested," according to the report.

Russell Viner, RCPCH President and professor of adolescent health at the UCL Institute of Child Health in London, told CNN: "We need to recognize that screens are ubiquitous in the modern world. We can't put the genie back in bottle."

"Although there are negative associations between screen time and poor mental health, sleep and fitness, we cannot be sure that these links are causal, or if other factors are causing both negative health outcomes and higher screen time," added Max Davie, RCPCH Officer for Health Promotion, said in a statement.

The report also highlights that there is no consistent evidence of specific health or wellbeing benefits of screen time either and calls for more research into the area, "particularly on newer uses of digital media, such as social media," according to Davie.

Divergence from previous guidelines

RCPCH's view diverges from a range of guidance , issued by other organizations and experts.

In 2016 by the American Academy of Pediatrics (AAP), recommended screen time usage dependent on the age of the child. This advised against any digital media for infants aged 18 months and younger, recommended an hour of screen time per day for children between the ages of 2 and 5, and said parents can determine the restrictions -- as well as monitor the types of digital media their children use -- for kids ages 6 and older.

In 2017, the American Heart Association suggested could contribute to future heart disease and recommended limiting exposure.

2018 study found that limiting kids' recreational screen time to less than two hours a day, along with sufficient sleep and physical activity, is associated with improved cognition.

RCPCH said in its guidance that recommendations by the AAP "and similar guidelines have been criticized as not being fully evidence-based and being focused on risks rather than recognizing the potential benefits of digital screen use in education and industry."

It added: "Given the controversy, it is essential we stick to the evidence."

Viner told CNN that there is a danger of AAP's health guidance being protective and "out of step with the modern world."

He gave the example of worries during the 1980s of TV screens impairing a child's development -- a fear that was later found to have no "conclusive evidence," he said.

"We need to think of screens as a form of information giving that has some commonality with older versions of it," such as televisions, listening to the radio or reading books, Viner added.

Limits based on individual needs

The new guidance has however advised against children using devices an hour before bedtime because of evidence that this can disrupt sleep.

"Some manufacturers have introduced 'night-modes' which emit less blue light, but there is no evidence that these are effective so we do not think that this makes screen use before bed 'OK,'" the guidance notes.

The report suggests parents negotiate limits on televisions, tablets or smart phones with their children based on their individual needs.

It includes a series of questions to help families make those decisions. These include: Is your family's screen time under control? Does screen use interfere with what your family want to do? Does screen use interfere with sleep? Are you able to control snacking during screen time use?

"When it comes to screen time I think it is important to encourage parents to do what is right by their family," Davie said. "However, we know this is a gray area and parents want support.

"We suggest that age appropriate boundaries are established, negotiated by parent and child, that everyone in the family understands. When these boundaries are not respected, consequences need to be put in place."