Women who sleep with lights on may gain weight: study

The internet is filled with brand new stories that talk about absurd medical studies and how they link to certain ailments. While consuming something harmless may lead to cancer, not sleeping enough may be doing more than just making you tired. So what should you believe? We think whatever makes sense to you. Speaking of absurd new studies, here’s another one. Women who sleep with artificial lights around them, gain weight or become obese in the future. This study, that was published in the journal, ‘JAMA Internal Medicine’ is the first one to find this association between artificial light and weight gain in women.

Aside from the results, the study suggested cutting off lights at bedtime to reduce the chances of becoming obese. Lead author Yong-Moon (Mark) Park said, “The research suggests a viable public health strategy to reduce obesity incidence in women.” For the study, the research team used questionnaire data from 43,722 women. The participants, aged 35-74 years, had no history of cancer or cardiovascular disease and were not shift workers, daytime sleepers, or pregnant when the study began.
The questionnaire had questions about if the women slept with their lights on, a small nightlight, light outside the room or light or television in the room. The research team measured the weight, height, waist and hip circumference to compare with followed up measurements to deduce the gain in weight. Scientists observed weight gain in women exposed to artificial light at night with women who reported sleeping in dark rooms.

The results were affected by the levels of exposure to artificial light at night. For example, using a small nightlight was not associated with weight gain, whereas women who slept with light or television on were 17 percent more likely to have gained 5 kilograms, or more over the follow-up period. The association with having light coming from outside the room was more modest.
“Humans are genetically adapted to a natural environment consisting of sunlight during the day and darkness at night,” 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.”
The authors acknowledge that other confounding factors could explain the associations between artificial light at night and weight gain.