Original: Decreased desire to eat is termed anorexia , while polyphagia ( or '' hyperphagia '' ) is increased eating . Dysregulation of appetite contributes to anorexia nervosa , bulimia nervosa , cachexia , overeating , and binge eating disorder .
Simplified: A loss of appetite is also called anorexia ( this is not the same as the eating disorder anorexia nervosa ) .