Final answer:
Anorexia nervosa is the eating disorder characterized by an obsession with becoming extremely thin and includes a fear of gaining weight alongside a distorted body image, often leading to severe health complications.
Step-by-step explanation:
The eating disorder characterized by an obsession with an unattainable image of perfect thinness is known as anorexia nervosa. People with anorexia nervosa consume very little food despite being fixated on it, and they harbor an intense fear of gaining weight, often leading to excessive exercise. Despite being dangerously underweight, individuals with anorexia nervosa often possess a distorted body image that makes them believe they are overweight, a condition commonly referred to as body dysmorphic disorder. This eating disorder can lead to several health issues including malnutrition, electrolyte imbalances, and severe medical complications if left untreated.
Other eating disorders like bulimia nervosa and binge eating disorder also present serious health risks, although they are characterized by different eating patterns. Bulimia nervosa involves cycles of binge eating followed by purging to avoid weight gain, while binge eating disorder is marked by compulsive overeating without subsequent purging. The health consequences of these disorders are distinct, yet all can have life-threatening outcomes without proper treatment.