Sleeping with a TV on or with other artificial light in the room has been linked to a higher risk of weight gain or obesity. A new study published by the National Institute of Health in JAMA Internal Medicine shows a positive correlation between sleeping with artificial light and overall weight gain. Chandra Jackson, Ph.D., and the study’s co-author, commented, “Exposure to artificial light at night may alter hormones and other biological processes in ways that raise the risk of health conditions like obesity.”
The analysis used questionnaire data from nearly 45,000 women between the ages of 35 and 74. The women had no history of cancer or cardiovascular disease. The researchers also made sure they didn’t work shifts, sleep in the day, and weren’t pregnant when the study started. The participants self-reported their sleep habits and whether they slept in total darkness or in the presence of artificial light from a television, phone screens, or nightlights.
The women’s weight and body mass index measurements were collected when the study began. New figures were collected at the end of the five-year study period. The women who slept with the light or TV on were 22 percent more likely to put on weight over a five-year period than those who slept in dark rooms or with a small nightlight. The average weight gain for those participants was 11 pounds.
There are a number of conclusions that can be drawn from these results. Artificial light has been shown to hamper sleep quality, while lack of deep sleep and not getting enough sleep overall are both correlated with health issues including obesity. Exposure to artificial light at night could also be reflective of unhealthy behavior, such as eating badly, sedentary lifestyle, or high levels of stress. More research will be needed to fully explain the link between sleeping with artificial light and weight gain.