Imagine this – you are busy with your hectic work schedule at home. With no time to spare for your little one, you promptly switch on his/her favorite video on your smartphone and hand it over to him/her. Within no time your bundle of joy is happy lapping up the songs and colors of the video while you effortlessly go about your chores. Bliss! However, what you do not realize is, this gesture is only going to put your baby into the path of a potential health hazard. Because, according to a recent study, excessive exposure to artificial lights makes kids overweight (1).
When your baby was born, his/her body clock – also known as the circadian clock, which helps regulate the body’s day and night changes, was not established. Therefore, you had to put in a lot of effort like keeping your house brimming with activity during the day and dimming lights and cutting out noises at night to help your baby set up his body clock correctly. However, by addicting your child to electronic devices like tablets and smartphones, you invariably end up doing the exact opposite of what you did earlier – confuse the body clock system. Not only that, but the prolonged exposure to the light emitted by these gadgets makes your child prone to obesity.
In a research conducted by the Queensland University of Technology, Brisbane, Australia, 48 children aged 3 to 5 from six Brisbane child care centers were studied over a two-week period (2). The Sleep in Early Childhood Research Group measured each child’s sleep, activity, height, and weight along with light exposure, and their BMI was calculated. To their surprise, the researchers found that children who were exposed to more light, including artificial light, during the latter part of the day and their sleep timings contributed significantly to their weight gain. What was even more surprising was that the amount of physical activity did not make any difference to their weight gain.
However, kids who were exposed to maximum light during the day when the sunlight peaks – afternoons – were found to be unaffected by weight gain, even when they were indoors. In fact, they were found to be slimmer. So, what is the relation between light and weight gain, you may ask?
Well, let us understand the circadian clock. Nature has worked out everything neatly. The circadian clock or our body clock works like a solar device. Its impact on our sleep patterns, weight loss or gain, our mood, and our hormones depends on our exposure to light, more specifically to natural daylight. However, with the advent of technology and artificial lighting, light exposure is not limited to daytime alone. Even after nightfall, or a little before sunset, on come the artificial lights in the form of street lights, home lights, light emitted by television sets, smartphones, tablets, and other such gadgets. So, instead of the body and mind slowing down exactly when nature wants us to, these artificial lights confuse the body clock into slowing down the production of melatonin, the hormone responsible for sleep. Worse still, by giving gadgets into our kids’ hands, we accustom their body to more number of hours of light exposure, which obviously affects their sleep pattern too. Throw in a couple of hours of physical inactivity, and you have a perfect recipe for early childhood obesity!
According to the researchers, this is the first time that light has been associated with obesity (3). While earlier physical inactivity, improper dietary choices, and insufficient sleep patterns were proved to be the causes of obesity, this new research can provide the necessary breakthrough in tackling this global health problem effectively.