Gained a little weight lately? Blame your television and laptop screen — and not just because of all that couch-potato time.
A study published this week reveals that weight gain may be directly linked to how your body responds to light from televisions and computers late at night.
Researchers at Ohio State University and the University of Haifa found that being exposed to unnatural light at night alters the body’s circadian rhythm (essentially your biological clock) and lowers its metabolism.
The study observed male mice to determine how bodies respond to late-night light. Researchers fed three groups of mice the same amount at the same time, but exposed them to light for different lengths of time: Group one experienced a natural 16 hours of light and eight hours of darkness, group two experienced 16 hours of light and eight hours of dim light, and the third group was exposed to light constantly.
At the end of the eight-week study, the mice who never existed in total darkness weighed about 10 percent more.
Besides weight gain, mice also experienced “impaired glucose tolerance,” according to a story in the LA Times.
Researchers noted that the mice ate at different times based on light exposure.
Mice are nocturnal and usually consume most of their food at night. But mice exposed to dim light reversed that pattern and ate more food during the fully lit phase.
“These results suggest that low levels of light at night disrupt the timing of food intake and other metabolic signals, leading to excess weight gain,” the study’s authors wrote. “These data are relevant to the coincidence between increasing use of light at night and obesity in humans.”