One reason that people may gain weight could be due to how much light they are exposed to, according to new research published in the Proceedings of the National Academy of Sciences.
Scientists housed mice in three different conditions for the study. One group was subjected to light 24 hours a day while another group was exposed to a light for 16 hours and then dark for the remainder of the day, which is a standard cycle. The rest of the mice lived in 16 hours of daylight and 8 hours of dim light.
The amount of food the subjects ate as well as physical activity were measured throughout the day. At first, food was not restricted but was later limited in a second study. At the end of each week, the scientists calculated the body mass of the mice.
In conclusion, the subjects who were exposed to light at night gained the most body mass, compared to those who lived under the standard conditions. The researchers also discovered that the mice who gained the most weight also had impaired glucose tolerances which are signs of pre-diabetes.
Overall, the scientists noted that the timing of eating contributes to weight gain as well as the extent of light exposure throughout the evening hours. Experts suggest to maintain a healthy diet, individuals should remain physically active and keep track of their caloric intake.