Sleeping with lights on has been linked with an increased risk of weight gain and obesity, said a new study published in the medical journal JAMA Internal Medicine.
Dale Sandler, a senior investigator at the National Institute of Environmental Health Sciences in North Carolina and senior author of the study, explained that sleeping with a television or light on in the room was associated with a 17% higher risk of gaining five kilograms over a five-year period among women, with a 22% chance of becoming overweight and a 33% chance of becoming obese.
"We are in the middle of an obesity epidemic in the United States and the things that we usually think about for obesity prevention are hard for people to do -- eat a better diet, get more exercise -- and we don't seem to be making a dent," Sandler stressed.
"If these study findings are true and if they can be replicated then it's a very easy public health message to turn off the lights when you're sleeping,” she added.
"Humans are genetically adapted to a natural environment consisting of sunlight during the day and darkness at night," Chandra Jackson, Ph.D., and the study’s co-author said. "Exposure to artificial light at night may alter hormones and other biological processes in ways that raise the risk of health conditions like obesity.”