Keep the dream alive: why waking up later is good for us all

Dr Paul Kelley says children are losing 10 hours of sleep a week - and it's all down to a clash between school start times and teenage body clocks

Sleep expert Dr Paul Kelley sounds a bit tired. He's a morning type, which means he wakes at 6am after about eight hours of sleep. It's lunchtime when we speak; he's been up almost seven hours and he may seem weary because he's being pursued by the world's media who all want to speak to him about sleep - and the lack of it.

Last week, Kelley, American-born but now based in Tyneside, gave a thought-provoking speech to the British science festival in which he called on schools to let teenagers lie in and suggested that lessons should be put back to as late as 11am to address a crisis in sleep deprivation among young people.