In the past, poor sleep has been linked to an array of dangerous medical conditions, as well as apparently shortening life expectancy in general.
However, other conflicting reports suggest that getting eight hours is a myth and that you will operate better on as little as five hours sleep. Even ex Prime Minister Margaret Thatcher famously claimed to get by on only four hours a night.
Confusing! But what's the real answer here? Should we be spending more time snoozing or is it all just a scientific myth? Reveal's Dr Phil sets the record straight: "Getting little sleep can certainly harm you in the long run, and has been linked to heart disease, diabetes, obesity and difficulty thinking straight," he says.
"Recent research compared the genes of good sleepers and poor ones and found that poor sleepers had 700 alterations to the way their genes worked, changing the chemistry of the body.
"The theory is that poor kip prevents the normal repair of tissues in the body that occurs when we rest, which might explain why tired people look so unhealthy."
However, that doesn't mean we should be going over our recommended sleeping allowance: "Oversleeping isn't great for you, either.
"Try to aim for eight to nine hours a night and get up at the same times every day. And don't watch TV in bed – it's a stimulus."
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