Have you been eating a lot at night? Do not dismiss it as a simple case of midnight snacking - a study suggests that it may be a red flag for mental health disorders including depression and self-injury.

Researchers from the University of Pennsylvania led by Dr. Rebecka Peebles recruited 1,600 students and were given questionnaires to assess the probability of them having eating disorders and to look at their overall mental health.

"Night eating syndrome is characterized not only by eating at night - certainly many college students might have a late night study fest with eating - 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," said Dr. Peebles to Reuters Health.

Their analysis revealed that three percent of the students experienced night eating after controlling binge eating. The number seemed pretty low but they still researchers were still alarmed because of other medical conditions that may be linked to this disorder.

Night eating and binge eating are different, since the former is not necessarily bingeing or overeating but is characterized by excessive eating. It is associated with another eating disorder called Anorexia nervosa, as well as ADHD medication.

Some people have reported waking up in the middle of the night to eat to help them fall asleep again. Young adults and stressed college students are likely to exhibit this behavior. This was a recent discovery because past studies have not separated the cases of excessive eating at night and simple binge eating.

In 2008, a survey was conducted and revealed that students who have night eating disorder have been depressed and physically hurt themselves in the past. It has also shown that the syndrome was linked to other eating disorders that could eventually cause grave physical and psychological outcomes if it were to continue without treatment.

If one sees signs of night eating disorder in oneself or other people, it is highly recommended seeking help from a doctor.

This study was published in the Journal of Adolescent Health.