There is good evidence that shows that poor sleep can affect academic performance in children and teenagers and can have effects on other important aspects of their development.
Teenagers need to sleep longer and go to bed later than preteens and there are a number of reasons for this, both physiological and social.
Sleep is vitally important for good physical, mental and emotional health and it is crucial for a child's development.
Sleep is important because of its involvement in memory, learning and physical and emotional development and so it is clear that the physical and emotional changes that are associated with puberty can account for the lengthening of the sleep time. However, the shift in when they go to bed is perhaps more complex, with both a physiological change as well as social factors playing a part, for example, the influence of parents on bedtime is waning, with peer pressure and texting, TV and computers causing a desire to stay awake later.
So while moving the school start time to later may help, it could be seen by teenagers as a licence to go to bed even later, so it is much more important to get a good night's sleep.
Dr Neil Stanley is a sleep consultant and author of 'The Sleep Report'