REARCHERS in Glasgow have helped formulate "the perfect recipe for a healthy day" for children.

The guidance covers 24 hours and includes how much time young people should spend sleeping, exercising and watching screens.

Nine to 11 hours of uninterrupted slumber is recommended for children aged five to 13, while those aged 14 to 17 should sleep for eight to ten hours at night.

Exercising at a moderate or vigorous pace should take up an hour every day overall, according to the guidelines, but there should also be several more hours of light activity.

Time in front of the TV, computer or i-pad is limited to two hours or less a day, by the researchers.

The rules were drawn up by a team at Glasgow Caledonian University in conjunction with experts in Canada where the project was funded and launched.

Canadian researchers and Dr Sebastien Chastin, reader in health behaviour dynamics at GCU, sampled sleep duration, sitting time and physical activity of more than 4,000 Canadian young people for the programme.

Dr Chastin said: “We have long known that engaging in moderate to vigorous activity is beneficial to health, but what we did not know is the effect of what we do during the rest of the day. In recent years it emerged that sitting too long and not sleeping enough might have an adverse effect on health even if we engage in the recommended 30 minutes of daily physical activity.

“The day is like a cocktail made of different parts; sleeping, sitting, doing light activities such as daily chores and hopefully engaging in at least 30 minutes of moderate to vigorous activity. To be healthy, we need to get the cocktail right. The compositional analysis we have developed allows a breakthrough in finding the perfect recipe for a healthy day.”

The findings have been published in the journal Applied Physiology, Nutrition and Metabolism.