Are you in the habit of sleeping with a light on? If so, you may find that you gain weight, even if nothing else in your life changes. For example, you could eat the same, and have the same amount of physical activity, and still gain weight if you sleep with a light on. Do darkness and light really effect weight gain? A recent study says they do!
The Light/Dark Study for Weight Gain
The study was conducted at Ohio State University, and the lead author of the study was Laura Fonken. The study was published in the online version of the magazine “Proceedings of the National Academy of Sciences.”
The study involved three groups of mice. Human subjects were not used. One group of mice was exposed to full light conditions twenty-four hours per day. Another group was exposed to dim lighting, and the third group was exposed to normal lighting conditions, or sixteen hours of normal lighting and eight hours of darkness. The study lasted for an eight week period, and the subjects were fed the same amount of food, and had the same level of activity.
Why Did One Group of Mice Gain Weight?
The group of mice that were exposed to full light at all times ate while the other groups were resting. Remember that the mice were fed the same amounts of food, but the food was available to them at all times. When the other mice were resting, the ‘lighted mice’ were eating.
When the researchers did not make the food continually available, and only gave the mice food at specific times – during normal waking hours – the group of mice that were exposed to full light at all times did not gain weight.
What Have We Learned from this Study?
What we have learned from this particular study is that the time of the day – or night – that you eat plays a role in whether or not you will gain weight. It really has nothing to do with the light exposure, but instead has to do with the time that you eat. We already knew that people who worked the night shift were more prone to being overweight than those who worked the day shift – and now we are certain that this is due to the time that they eat.
What it comes down to is that if you want to lose weight, restrict your eating to daytime hours, and avoid eating at night. If you work in a job where you must be awake at night, and sleep during the day, eat your two biggest meals before you go to work, and after work when it is light outside.