The scientists conducted an eight-week experiment in which three groups of rats were exposed to light for 16 hours during the day and then to dark, dark, and dark for eight hours each day  All rats were fed exactly the same amount of food during the experiment  They found that mice exposed to low light at night, and with lights on, gained weight
According to statistics, in western cities with brightly lit street scenes at night, most of those who often receive the light from computers and televisions are not obese
 From this, the researchers concluded that the prevalence of obesity in the West is closely linked to brightly lit street scenes and the light from computers and televisions at night