I still remember the good old student days, where nights were longer, either due to an exam or goofing around with friends. The sleeping habits were irregular and eat habits as well. Did it ever occur to you that exposure to light at the night time along with food intake can take you to a higher risk of being obese? The jury is still out there for humans, but a study conducted on mice shows that exposure to light during night can make them obese.
About the study
The study was a collaborated effort by researchers at Ohio State University and the University of Haifa in Israel. The study involved
- exposure of mice to dim and bright light
- effect on metabolic activity was analyzed due to exposure to light
The study was published in Proceedings of the National Academy of Sciences.
Results of the study
The results of the study were interesting and it was observed that
- Dim and bright light exposure significantly increase body mass index (BMI) of mice.
- These exposure also reduce glucose tolerance level of mice, when compared to the group that lived in normal/ dark cycle
The study, even though small, pointed towards the fact that there is correlation between time at which mice ate and the light intensity level. This is also driven by the fact that mice that ate in day time were fatter and normally rodents eat more during night time. I am sure you have experienced...
movement of mice or holes in sack or container of grains in night time, which would tell you mice like to eat in the night.
Why would light exposure increase weight?
The reason is not clear yet, but researchers think based on the results that low levels of light is affecting the metabolic signals in night time when these animals/ rodents eat and hence leading to weight gain.
How does this study influence humans?
Although the study was not conducted on humans, but it would be critical to think that metabolism is affected by exposure to light during the time, when body is not expecting that light. This was true in case of mice. With humans, advent of internet era, gaming industry, call center culture and what not, we are trying to work and eat at the time, when body is expecting us to sleep or be in dark. That can have effect on our metabolic activity and hence increase propensity to gain weight.