Catching up on lost sleep may be one way to reduce the risk of diabetes, according to new research.
Scientists found that three nights of "catch-up" sleep improved the body's insulin response and helped to clear sugar from the bloodstream.
Previous research has shown that restricting sleep can have a bad effect on insulin sensitivity.
Both studies appear to show a strong link between sleep and the body's use of insulin. A poor insulin response can result in type 2 diabetes, which affects almost three million people in the UK.
Dr Peter Liu, from the Los Angeles Biomedical Research Institute in the US, who led the latest work, said: "We all know we need to get adequate sleep, but that is often impossible because of work demands and busy lifestyles. Our study found extending the hours of sleep can improve the body's use of insulin, thereby reducing the risk of type 2 diabetes in adult men."
Insulin is the hormone that regulates blood sugar level. A person with type 2 diabetes becomes "resistant" to insulin and stops responding to it properly.
The new research, presented on Tuesday at the Endocrine Society's annual meeting in San Francisco, focused on 19 non-diabetic men who complained of not getting enough sleep during the working week. On average, they were sleeping no more than 6.2 hours on week nights, but frequently slept a couple of hours longer at the weekend.
Observing the men in a sleep laboratory showed how the catch-up sleep boosted insulin sensitivity and improved test scores for insulin resistance.
"The good news is that by extending the hours they sleep, adult men who over a long period of time do not get enough sleep during the working week, can still improve their insulin sensitivity," said Dr Liu.