We joke about needing our beauty sleep, but there may actually be something to that. Swedish researchers have found scientific evidence supporting the concept of beauty sleep.

The study involved a group of 23, sleep deprived adults (age 18-31) who were photographed and 65 untrained observers (age 18-61) who rated the photographs.

Results indicate that sleep deprived people appear less healthy, less attractive and more tired compared with when they are well rested.

“I believe that humans are rather sensitive in detecting sleep loss related facial cues in other people,” says lead researcher John Axelsson.

The authors of the study, first published in 2010 in the BMJ (British Medical Journal) suggest that future studies should focus on the relevance of these facial cues in clinical settings. Axelsson says his team is working on several follow-up studies, including which exact facial features are affected by sleep deprivation and convey fatigue and how these effects relate to behavior related outcomes.

In addition to affecting your appearance, lack of sleep also increases your risk of obesity, diabetes, high blood pressure, heart disease and depression.