Everyone has heard or read somewhere that you shouldn't eat anything at night or at least less so you don't get fat. However, this is not true. Excess calories make you fat. This means that you are adding more energy (in the form of calories) to the body than you burn (basal metabolic rate plus physical activity) causing you to gain baody fat in the long run. On the other hand if you burn more calories than you consume you will lose body weight.
If the energy consumed is the same as the amount of energy supplied, you will neither lose nor gain body weight [1]. Studies show that it does not matter when you consume excess calories during the day [2]. There is even a study that states that eating late tends to favor the percentage of fat-free mass [3].