Researchers Laura Fonken and Randy Nelson of the University of Ohio have observed that mice exposed to light at night gain 50% more weight than mice exposed to darkness at night, apparently despite all eating similar amounts of food.

The light of the night seems to cause the mice to eat during the breaks, causing obesity, unlike eating during normal hours. In another trial, researchers kept some mice under light, but only fed them during normal hours. They did not thicken more than those who were in the dark at night. Thus, researchers believe that the body metabolizes what it eats at one time or another in a different way. To be more precise, they think that nighttime luminosity can affect a hormone involved in metabolism.

These tests are intended to be performed with the human being, while extrapolating what happened with the mice, it can be concluded that eating late and/or working at night can lead to different metabolizations, causing obesity.