Exposure to light overnight may lead to negative effects on one’s body mass index, according to results published in the journal Proceedings of the National Academy of Sciences. This is because one’s eating habits may increase one’s dietary intake, and cause unnecessary weight gain.

During an eight-week study, researchers put a group of mice on a restricted diet while exposing them to continuous lighting throughout the night. The weight gain of these animals was then compared to a control group, and as a result, the team found that neither group gained weight.

However, when food consumption wasn’t restricted, the overnight light exposure caused the mice to become nocturnal and eat more. In fact, this group ate 55 percent of the time during daylight hours, while 36 percent of the control group’s eating occurred during the day.

Randy Nelson, co-author of the study, stated that “it may be that people who use the computer and watch the TV a lot at night may be eating at the wrong times, disrupting their metabolism.” He concluded that “clearly, maintaining body weight requires keeping caloric intake low and physical activity high, but this environmental factor may explain why some people who maintain good energy balance still gain weight.”

An estimated 18 percent of all adolescents and teenagers in the U.S. have an abnormally high body mass index, the Centers for Disease and Control Prevention reports.