Allied health care professionals who are trained specifically in the field of nutrition are called dieticians.An athlete's performance can be enhanced with the aid of sound nutrition,and the dietician is the resident expert in this fields.For example, during the rehabilitation process, the dietician may be consulted when an athlete is being treated for a psychological problem in the form of an eating disorder. Athletes being rehabilitated for physical problems may also exhibit nutritional problems that the dietician may assist in managing.Most dieticians are employed by a hospital.Often, they serve as consultants to athletes and teams on dietary matters.The dieticians areas of expertise in sport include weight gain and loss,bulimia, anorexia nervosa, pre-competition meals,proper hydration, and nutritional supplementation.