Lack of sleep can harm the metabolism and increase the risk of diabetes a new study found.
Researchers at the University of Chicago found that too little sleep affects the cells and slows down the metabolism.
This increases the risk of insulin resistance, said CNN.
"It's always been thought that the primary function of sleep was for the brain, but in addition to the brain, your fat cells also need sleep," said study co-author Matthew Brady, reported HealthDay.
"Too little sleep makes you groggy, and the same thing happens on a metabolic level. Cells don't behave as they normally would, and this can lead to insulin resistance."
A lack of sleep has been linked to insulin resistance and other ailments in the past but the causes had never been studied at the cellular level.
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The study looked at seven young adults who were assigned 8.5 hour sleeps and 4.5 hour sleeps.
Researchers took samples of fat cells and took glucose levels after each sleep.
Those who lacked sleep had fat cells' ability to respond to insulin shrink 30 percent and had insulin levels three times higher than their peers who were well rested, reported the Los Angeles Times.
In this situation the pancreas begin to produce more insulin and increase the risk of type-II diabetes.
"A lack of sleep can really set up a vicious cycle. Sleep should be considered as important as diet when you're trying to prevent weight gain and diabetes," Shelby Freedman Harris, director of the behavioral sleep medicine program at the Montefiore Medical Center in New York City, told HealthDay.
The findings were published in the Annals of Internal Medicine.