By Professor John J Reilly, Professor of Physical Activity and Public Health Science, University of Strathclyde

SOCIAL media has been front page news recently, implicated in a number of tragic deaths of UK teenagers. Children and adolescents, and now even babies and toddlers, seem to be increasingly dependent on screens to fill their waking hours, and many of their sleeping hours. Sound advice is needed urgently, particularly for families and health professionals.

Internationally, recreational screen time (outside of school and nursery) is high on the public health agenda. The landmark World Health Organisation (WHO) Ending Childhood Obesity Reports in 2016 and 2017 concluded that reducing screen time in early childhood was central to the prevention and treatment of obesity. A thorough review of the evidence by the World Cancer Research Fund in 2018 concluded that high exposure to screen time in childhood was a major cause of obesity, and via, obesity, a major cause of many cancers in adulthood.

Since 2016, thorough reviews of the evidence in Canada, Australia, New Zealand, and South Africa have shown conclusively that less recreational screen time is better for health and development right across infancy, childhood and adolescence. "Better" here means a much-reduced risk of obesity, healthier diet, higher physical fitness, better cardiovascular health, better sleep, improved physical fitness, and improved cognitive, social, and emotional development, including better quality of life and feelings of well-being. These evidence reviews have led to recommendations in those countries that recreational screen time should be avoided in the under-twos, limited to one hour per day in two-to four-year-olds, and to two hours per day in five-17-year-olds. Importantly, these recommendations have been supported by stakeholders, including families and health professionals. The WHO has been reviewing the evidence and will probably adopt the Canadian/Australian/ South African guidelines for the under-fives globally in 2019.

The issue of screen time in childhood has received health policy attention for the first time in the UK with the publication of the Chief Medical Officers’ (CMOs) statement today (February 7). This statement was not based on a thorough review of the evidence, does not appear to have considered the recent evidence reviews and recommendations from other countries and WHO, and appears not to have involved any meaningful consultation. The CMOs also seem to have interpreted the precautionary principle as being about the need to protect screen time rather than the need to protect children. Crucially, no limits on time spent in front of screens were suggested.

The alarm bells on screen time and public health have been ringing loudly outside the UK for some time, but they have not been heard, or not been listened to, in health departments here. This is especially puzzling in Scotland, where new guidelines will also be announced. The Active Healthy Kids Report Cards published since 2013 show that between 100,000 and 200,000 Scottish children and adolescents are already obese, and excessive screen time has become the norm.

Bold and urgent action on screen time is needed, and so the CMOs statement today was an opportunity lost. It seems that the screen will be the elephant in the public health room for some time in the UK.