Many people like to slide the phone before bed, this bad habit not only affects the quality of sleep, research has found that may also increase the health risks of female obesity. What are the reasons?
Many people know that sliding a cell phone, looking at a computer or watching TV before bedtime can affect sleep, and now you have an additional reason to turn off your phone early. Studies have found that exposure to light from TVs, computers and cell phones before bedtime can increase obesity in women.
The National Institutes of Health Institute of Environmental Health Sciences published in the Journal of American Medical Association Internal Medicine (JAMA Internal Medicine) study, the first to find a relationship between light and female obesity.
The body has a natural clock called the circadian rhythms, which means that there is a mechanism to notify the body that it is time to sleep and to wake up.
The dominant clock is in the brain, called the suprachiasmatic nucleus (SCN). This “central timing system” built into the brain coordinates the body’s natural rhythms, and light may disrupt the functioning of this “timing system. Because there is a special light-sensitive cell in the eye that detects light to send messages to the body and secrete hormones, this is why we want to sleep when it is dark and get up when it is light.
However, humans are still affected by many artificial lights at night, such as television, cell phones, streetlights, convenience store lights, etc. Animal studies in the past have confirmed that exposure to light at night will affect the secretion of melatonin, which also affects the day-night rhythm, thus changing eating patterns and gaining weight.
The study asked 43,000 women, 35-74, who did not have cardiovascular disease and did not work shifts, about their exposure to light at night, both indoors and outdoors, as well as their height and weight, waist-to-hip ratio, and calculated body mass index before and after the study. After five years of follow-up, and after correcting for influencing factors, it was found that 17% of women who slept with the lights on or watched TV gained 11 pounds (about 5 kg) more on their bodies. In addition, 22% of women became overweight and 33% became obese.
According to U.S. standards, both are calculated by body mass index (BMI), overweight means BMI greater than 25, obesity is greater than 30.
“Humans are genetically adapted to light, but exposure to artificial light at night alters hormones and other physiological operations, thus increasing health risks such as obesity,” co-author Chandra Jackson told the press
Unhealthy diets and sedentary lifestyles have been the most common explanations for the rise in obesity around the world in the past, and this study points in another direction, to the effect of artificial light at night on obesity in women.
“Preventing obesity has been difficult because it requires people to change their diets or exercise more, so it’s hard to make progress. If more studies confirm this conclusion, public health advocacy should call for turning off light at bedtime,” first author Dale Sandler told CNN.
For individuals, the solution is very simple, do not want to gain weight, before bed to cut off the light source of all devices, including TVs, cell phones, tablets, computers, etc..
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