A recent study investigated the effects of artificial light on sleep. The study of 43,722 women reveals that sleeping with a light source such as television promotes weight gain and health problems in the long term.
We already know the main external factors that increase the risk of obesity: lack of physical activity, a high-calorie diet, stress or sleep quality. But a new study went further on this last factor: the impact of light on weight gain. According to the researchers, turning off the television and cutting off any artificial light source at bedtime would be the right way to reduce the risk of gaining weight.
Sleeping with the television on = 5 kilos more
To evaluate this criterion, the researchers interviewed 43,722 women and measured their weight, height, waist, and hips. Aged between 35 and 74 years, the participants did not have habits of life that could influence the study such as sleeping during the day or being employed in shift work (such as the 2×8 or 3×8). The survey asked the participants that slept with more or less light sources nearby.
The results allowed the researchers to deduce the impact of artificial light on weight gain. If for example the use of a small night light did not have a high incidence, falling asleep near a lamp or television had an additional 17% chance to take 5 kilos. The presence of light emanating from another room, however, had no obvious effect.
How does it work?
During sleep, a hormone is naturally produced by the human body: melatonin , the release of which influences the biological mechanisms of the body, and which depends largely on the light, as Dr. Chandra Jackson, co-author of study, explains: “Humans are genetically accustomed to natural light changing between day and night Exposure to artificial light disrupts the functioning of the body and increases the risk of health problems such as obesity.”
Urban dwellers are more exposed
Beyond reducing the light sources at home, the co-author emphasizes that people living in the city are more exposed to artificial light by the neon stores, lights of buildings or signage. It should be noted, however, that this study focused exclusively on a sample of women. Other scientific research will have to be carried out to confirm this tendency in men.