The study was conducted by researchers led by Dr. Leonie Balter from Stockholm University, Sweden.
The effect of sleep on a person's age appears to be related to how sleepy a person feels. Feeling young is not just a personal feeling, but rather something related to health data. Previous studies have shown that feeling younger than one's age is linked to a longer and healthier life. Not sleeping enough hours for a long period of time is associated with an increased likelihood of death and increases social burdens associated with a number of diseases.