Not getting a full night's sleep slows a person's ability to burn calories and makes them gain more weight, according to a shocking new study by two German universities.
Researchers said subjects reported feeling unusually hungry while sleep deprived. Fatigue made them move slower and do less physical activity, causing them to burn fewer calories.
The study was announced Tuesday at the annual Society for the Study of Ingestive Behavior 2012 Conference in Zurich, Switzerland.
Fourteen healthy men of normal weight were selected as subjects. They were evaluated twice; once after having slept a full eight hours and once after staying awake for 24 hours.
Subjects kept journals, logged all food consumed, wore devices to measure their physical activity and amount of calories burned, and underwent blood tests.
Their blood tests showed a higher level of ghrelin, also known as the hunger hormone. The lack of sleep also caused the body to burn less calories while at rest.
The scientists behind the study believe that future studies should be done to see if increasing the hours of sleep could be possible treatments for diseases related to weight gain such as obesity and type-two diabetes.