NEW YORK (CBSNewYork) – Just like your body needs sleep to function, your fat cells need sleep too.

Turns out, sleepy fat cells are bad for health, TV 10-55′s Katie McGee reports.

Lack of sleep is linked to a host of health problems, from memory loss to a weakened immune system, to high blood pressure and obesity.

But how does lack of shut-eye cause these medical issues?

Turns out, your fat cells need sleep as much as your brain.

“The first-of-its-kind study in the Annals of Internal Medicine found that sleep deprivation – even for a short time – has a direct and harmful effect on fat cells,” said Dr. Matthew Brady.

Seven volunteers at the University of Chicago’s sleep lab had their sleep reduced from 8.5 hours to 4.5 hours per night, for four nights in a row.

“There was a 30 percent reduction in insulin sensitivity in subjects that were young, lean, healthy, and otherwise metabolically normal,” said Dr. Brady.

The researchers say the study helps shed novel light on the still elusive function of sleep. Shut-eye could be just as important as diet and exercise – just easier.