Sleeping with artificial light increases the risk of obesity in women. Women who do not want to get fat should sleep in a dark room, since a study has linked sleep with artificial light or with the television on with an increase in weight and a widening of the waist.
A study by the Institute of Science of Health and Environment of the United States, published in the journal Jama Internal Medicine , relates exposure to artificial light at night while sleeping with weight gain in women. Or, what is the same: if you want to maintain the weight, it is important to sleep in the dark.
For this research, its authors took data from 43 722 women from a study that examined environmental and family risk factors for developing breast cancer , conducted between 2003 and 2009. Participants, between 35 and 74 years of age, did not work for shifts or at night (which would have forced them to sleep for the day).
In the questionnaire the women were asked if they slept without light, with a small night light, with light coming from outside the room, or with a light or the television on in the bedroom . In addition, at the beginning of the study they were made different measurements such as weight, height, waist circumference and hip, and body mass index (BMI). Five years later, they had to report their weight and the other measurements.
Women who sleep with light get fat and their waist is enlarged
With that information, the researchers studied whether women who had gained weight slept with any source of light, or in the dark. And the results showed that the use of a small night light was not related to weight gain, but when the light came from outside it gained a little weight, and those women who slept with a light or with the TV on in the bedroom They had a 17% higher chance of winning 5 kg.
In addition, women who spent the night with a light source outside or inside the room, experienced an increase in the circumference of their waist between 41.6% and 50.5%, compared to those who rested without no light Regarding BMI, it was greater than 25 (which is already considered overweight) in 71% of women who kept a light on in their room at night.
The explanation to this phenomenon could be in the alteration of the circadian cycles , that is to say, the physical changes that take place in the human being influenced mainly by the light of the day and the darkness of the night. In cities, where there are light bulbs that enter through the window as street lamps, illuminated signs, etc., sleep hormones, and specifically melatonin , can be affected and increase the risk of obesity .
For this reason, although the authors of the work think that a causal relationship can not be established, they do believe that reducing exposure to artificial light at night could be a preventive measure against obesity.
Sleeping with artificial light increases the risk of obesity in women