Supplementation mainly based on the B-group vitamins can effectively improve and increase the appetite. These compounds have in fact very strong impact on all kinds of metabolic changes associated with proteins, carbohydrates and fats. A healthy metabolism of the athlete is a fast metabolism. In addition, supplementation improving appetite is particularly important for those hard and intensively training, having for example two workouts a day, because the functioning of their digestive system is reduced. Improved appetite is also a good medicine and the way to weight gain and adjunctive therapy in diseases such as anorexia or bulimia.