Final answer:
Anorexia nervosa is an eating disorder characterized by a distorted body image and maintaining a body weight well below average. A characteristic of anorexia nervosa is amenorrhea, the cessation of menstrual period in females.
Step-by-step explanation:
Anorexia nervosa is an eating disorder characterized by the maintenance of a body weight well below average through starvation and/or excessive exercise. Individuals with anorexia nervosa often have a distorted body image, referenced in literature as a type of body dysmorphia, meaning that they view themselves as overweight even though they are not.
One characteristic of anorexia nervosa is amenorrhea, which refers to the cessation of the menstrual period in females. This is often a result of the food restriction and excessive weight loss associated with anorexia nervosa.
Purging and avoiding exercise are not typically characteristic features of anorexia nervosa, but may be present in other eating disorders such as bulimia nervosa.