There are people who lose their appetite and do not eat when they are under a lot of stress, but most people tend to gain weight in these situations. This is due to cortisol, the stress hormone which stimulates appetite and forces the additional calorie intake. When under stress we tend to eat the foods we are not supposed to eat, like chocolate and junk food, which end up on our waist. Knowing this metabolic behavior, we should learn to go through the day as relaxed as possible. Working out at the gym and sports activities release stress and help us burn calories.