British children’s health would benefit from switching to continental time by moving the clocks forward an hour, say researchers.
Lighter evenings would increase the amount of time children engage in moderate to vigorous physical activity each day by an average of two minutes, a study shows.
According to the researchers, the difference this makes to children’s overall activity levels is “not trivial”.
“Evening daylight plays a role in increasing physical activity in the late afternoon and early evening – the ‘critical hours’ for children’s outdoor play”
The researchers compared 23,000 children aged five to 16 in England, Australia, the US, Norway, Denmark, Estonia, Switzerland, Brazil, and the Portuguese island of Madeira.
To test the effect of daylight on activity levels, the children wore accelerometers - electronic devices that measure body movement.
The results showed that children’s total daily activity levels were 15% to 20% higher on summer days when the sun set after 9pm than on winter days when darkness fell before 5pm.
This was especially true in European and Australian populations, even after adjustments for weather conditions and temperature.
Lead researcher Dr Anna Goodman, from the London School of Hygiene and Tropical Medicine, said: “This study provides the strongest evidence to date that, in Europe and Australia, evening daylight plays a role in increasing physical activity in the late afternoon and early evening – the ‘critical hours’ for children’s outdoor play.
“Introducing additional daylight savings measures would affect each and every child in the country, every day of the year, giving it a far greater reach than most other potential policy initiatives to improve public health.”
The findings appear in the International Journal of Behavioural Nutrition and Physical Activity.
A Bill on shifting the clocks forward for all or part of the year was debated in parliament between 2010 and 2012 but failed to become law. The proposals would have given children an estimated 200 extra waking daylight hours per year, said the scientists.
Several Australian states have also held referenda on the topic. The idea even gave rise to a single-issue political party, “Daylight Saving for South-East Queensland”, in 2008.
Co-author Professor Ashley Cooper, from the University of Bristol, said: “While the introduction of further daylight savings measures certainly wouldn’t solve the problem of low physical activity, we believe they are a step in the right direction.”