Netflix binge til you fall asleep? Too tired to turn off the TV? New research published in JAMA Internal Medicine suggests that exposure to artificial light whilst sleeping at night may be a risk factor for weight gain—the first ever study to find this connection.
Researchers at the National Institute of Environmental Health Sciences (NIEHS) used questionnaire data from 43,722 women who were asked whether they slept with no light, a small nightlight, light outside of the room or a light or TV on in the room.
By analysing self-reported fluctuations in weight, height, waist/hip circumference and body mass index, findings suggest that those who slept with a light or TV on were 17% more likely to have gained 5kg (approx 11 pounds) or more over the 5 year follow-up period (2003-2009).
Results varied depending on the level of artificial light exposure at night, with the use of small night lights not found to be associated with weight gain, according to the study.
We’ve all heard that poor quality of sleep in itself can increase the risk of obesity and weight gain and that light sources can suppress the sleep hormone, melatonin—and in turn, interrupt our natural circadian rhythms—but how?
Co-author Chandra Jackson, Ph.D., head of the NIEHS Social and Environmental Determinants of Health Equity Group says: “Humans are genetically adapted to a natural environment consisting of sunlight during the day and darkness at night.”
“Exposure to artificial light at night may alter hormones and other biological processes in ways that raise the risk of health conditions like obesity.”
Lead author Yong-Moon (Mark) Park, M.D., Ph.D., said the research suggests a viable public health strategy to reduce obesity incidence in women.
“Unhealthy high-calorie diet and sedentary behaviors have been the most commonly cited factors to explain the continuing rise in obesity,” Park said.
“This study highlights the importance of artificial light at night and gives women who sleep with lights or the television on a way to improve their health.”
Along with poor sleep quality been linked to an increase in appetite, sugar cravings and a slower metabolism, sleep specialist, Olivia Arezzolo tells Amodrn that a bad night’s sleep can also lead to you feeling stressed, depressed, anxious and ‘wired’. A previous study also suggests that as little as two nights of bad sleep can alter your gut’s microbiome.
What can you do about it? According to Olivia:
- Invest in a pair of light blockers to counteract effects of blue light from screens and wear 2 hours before bed
- Activate night mode on your smartphone
- Better yet, put devices away 60 minutes before bed
- Wear an eye mask upon falling asleep
