If only nourishment were a simple process: get hungry, eat, get full, stop eating. But an array of biochemicals sending signals between the brain and the body control both hunger and appetite, and the difference between the two is complex. While hunger is a physical need for food, appetite is a desire for food. Your appetite may encourage you to overeat, eat when you're not hungry and choose fatty, sugary and salty foods over something healthier. Eating to satisfy your appetite can result in excess calories and a weight problem that is difficult to control.