Final answer:
Anorexia nervosa is characterized by maintaining a much lower than average body weight through extensive calorie restriction and/or over-exercise, and it is associated with a distorted perception of one's body weight and shape, leading to severe health issues.
Step-by-step explanation:
The characteristic most consistent with anorexia nervosa is maintaining a body weight that is well below average through behaviors such as starvation and/or excessive exercise. This eating disorder is often accompanied by a distorted body image, which is a type of body dysmorphia, where individuals see themselves as overweight despite being underweight. Anorexia nervosa can result in severe health complications, including bone loss, heart and kidney failure, amenorrhea, and an increased risk for psychological disorders.
Those affected by anorexia nervosa typically present with an obsessive fear of gaining weight, along with a self-perception of being overweight, regardless of their true body size. Cultural ideals within Western societies often contribute to the prevalence of this condition, particularly among young females. The consequences of anorexia such as malnutrition, loss of bone mass, heart problems, and sometimes death, highlight the severe impact of this disorder.