Final answer:
Anorexia nervosa and bulimia nervosa are serious, life-threatening eating disorders, not phases or side effects of dieting. They necessitate professional treatment due to their severity and impact on mental and physical health.
Step-by-step explanation:
Anorexia nervosa and bulimia nervosa are not simply phases or the result of dieting; they are serious health-threatening problems. Both disorders involve an obsession with food and weight and can lead to dangerous health complications. Anorexia nervosa is characterized by self-starvation and excessive exercise, leading to dramatic weight loss and a distorted body image. Bulimia nervosa involves cycles of binge eating followed by purging, which can cause severe electrolyte imbalances and heart problems. These conditions are mental health disorders with a high mortality rate and often require professional treatment to address the complex psychological and physical aspects of the diseases.