The Sleep Diet

To some people, the need for sleep seems a sign of weakness. Getting by with less rest is the new macho – and women, especially, are buying into it. But while you’re asleep, every system in your body is being fine-tuned, reset, cleaned up and restored to its optimal operating mode by an army of molecular troubleshooters. New things you have learnt are being processed, memories are being organised and stored, and the immune system is building a new contingent of natural killer cells to fight off battalions of infectious agents. Growth hormone is being produced to repair damaged tissue (in adults) or build new tissue (in children) and to block the corrosive effects of stress.