Dieting And Falling Asleep With The TV On.
Sure we know we shouldn’t really be scrolling Instagram before bed, mainly because the blue light can stop us feeling sleepy, but new research has now uncovered a link between exposure to sleeping with artificial light and weight gain in women. Sleeping with a television or light on in the room may be a risk factor for gaining weight or developing obesity, according to scientists at the National Institutes of Health.
The research, which was published online June 10 in JAMA Internal Medicine, is the first to find an association between any exposure to artificial light at night while sleeping and weight gain in women. The results suggest that cutting off lights at bedtime could reduce women's chances of becoming obese.
Their findings are based on questionnaire data from 43,722 American women spanning the years 2003 through 2009. Participants were not shift workers, daytime sleepers, or pregnant when the study began (and no men were included, so we don't know if these findings apply to them too).
By analyzing self-reported fluctuations in weight, height, waist/hip circumference, and body mass index over the five-year period, they found that artificial light does indeed affect weight—but not all light is created equal. Sleeping with a small night light on, for example, wasn't associated with weight gain, but sleeping with the television on was. Light coming in from the outside didn't appear to have significant effects on weight, while bedroom light did.
Animal research and smaller studies in humans have linked prolonged light exposure with weight gain. Exactly how is uncertain but scientists think disruption in release of hormones related to sleep and appetite may be involved.
"Humans are genetically adapted to a natural environment consisting of sunlight during the day and darkness at night," co-author of the study Chandra Jackson 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."