1Researchers at a leading university have completed the largest ever study of sleep in teenagers.
2The ambitious project followed more than eight thousand secondary school students over a period of five years.
3Those who slept fewer than seven hours a night performed significantly worse in memory tests.
4The link between poor sleep and low grades remained clear and consistent across every single age group.
5Late night phone use proved to be the most common reason for going to bed so late.
6Many students openly admitted that they checked their phones within minutes of turning off the bedroom light.
7Based on these findings, the researchers suggest that secondary schools should start their lessons later each morning.
8The team also strongly recommends that parents set clear and firm limits on evening screen time.
9Some head teachers have warmly welcomed the findings, but others say later starts are simply impractical.
10The full report will be formally discussed by education ministers at a conference later this month.