How Much Sleep do we Need?

The old saying about needing seven hours sleep a night is broadly speaking true but only as a guideline. While there is a huge varation in how much sleep people need, seven to eight hours is ideal.

• Some can get by on a lot less, but studies show that if you increase from six hours a night to seven, it reduces your risk of heart disease.
• It seems that if you cut back on sleep in the long term, it makes your blood sugar levels go razy and, after a week or two, you can enter a diabetic state. 
• Sleeping for more than ten hours is also bad for you, but no-one knows why.

Michael Mosley in Radio Times October 2013