Night visits to the fridge may be a sign of a full-fledged mental disorder, researchers said.

Researchers from the University of Pennsylvania under the supervision of Dr. Rebecka Peebles, distributed questionnaires to a group of 1,6 thousand students to assess the possible eating disorders and evaluate the general state of mental health, reports Fox News.

Thus, night eating syndrome is characterized not only by eating late in the evenings and even at night - but it's also characterized by other things, like feeling that you can't eat in the morning, and feeling like you have to eat in order to go back to sleep.

3% of the students who took part in the survey had this problem. Night eating syndrome is linked with anorexia, as well as with taking drugs to treat hyperactivity and attention deficit disorder. Some people with the syndrome of night eating wake up in the middle of the night just to eat and then go bakc to sleep.

Young men and students are at particular risk of developing the syndrome. Back in 2008, a study was conducted which showed that students with this syndrome had depression and caused harm to themselves. Experts recommend to see a specialist urgently if there are any symptoms of the disease.