Turn off the light at night to lose weight

Persistent exposure to light at night may lead to weight gain even without eating more food.

Washington: It is well known that too much junk food and lack of exercise makes us fat. But a new research suggests there may be another factor at play: too much light at night.

The study in mice has shown that persistent exposure to light at night may lead to weight gain, even without changing physical activity or eating more food.

Researchers found that mice exposed to a relatively dim light at night over eight weeks had a body mass gain that was about 50 percent more than other mice that lived in a standard light-dark cycle.

"Although there were no differences in activity levels or daily consumption of food, the mice that lived with light at night were getting fatter than the others," said Laura Fonken, lead author of the study and a doctoral student in neuroscience at Ohio State University.

The study appears this week in the online early edition of the Proceedings of the National Academy of Sciences.