A new study explains that weight gain is linked with an increased exposure to light – this phenomenon was seen in lab mice, and the researchers suggested that it might be applied to humans as well. The findings have been published in the journal Proceedings of the National Academy of Sciences.
Gaining weight might occur as a result of overexposure to light, or exposure during odd hours. How does this happen though? The authors of the new study seem to have identified the mechanism behind.
The team of researchers of the study, from Leiden University Medical Center and from the Academic Medical Center located in The Netherlands, performed experiments on mice which were exposed to light for long periods of time. The researchers tested how efficient were the animals at burning the food they consumed. According to the findings, mice exposed to different light intensities differed in efficiency. As a consequence, some of them gained weight.
Gaining weight might occur as a result of overexposure to light, or exposure during odd hours. How does this happen though? The researchers of the new study seem to have identified the mechanism behind.
Lab mice were placed in enclosures where the day/night duration was changed. Groups were made to remain exposed to artificial daylight for 12, 16, and 24 hours for a period of one month. One of the hypotheses of the study was that brown adipose tissue (BAT) played a role in the weight gain due to light exposure and thus the BAT efficiency was monitored in all the mice; BAT is involved in the conversion of energy obtained from food into heat. Note that when food is not changed into heat, it is stored as fat.
While all the mice were fed with the same amount of food and made to exercise as much, the team found that mice exposed to light for longer time periods had lower BAT efficiency. Consequently, their bodies would store more food as fat instead of using it up into heat, and thus they gained weight.
The researchers therefore concluded that this might be the case for humans as well.