A patient was diagnosed with anorexia nervosa. The history shows the patient virtually stopped eating 5 months ago and lost 25% of body weight. The serum potassium is currently 2.7 mg/dL. Which nursing diagnosis applies?

Choice A reason: This diagnosis accurately reflects the patient’s clinical status. A 25% weight loss over 5 months indicates a severe nutritional deficit. The serum potassium level of 2.7 mg/dL confirms hypokalemia (normal range is 3.5 to 5.0 mg/dL), which is a common and dangerous complication of restricted intake and malnutrition in anorexia nervosa. Choice B reason: This choice is incorrect because the patient’s potassium level of 2.7 mg/dL indicates hypokalemia, not hyperkalemia (high potassium). Additionally, while swollen parotid glands occur in purging-type anorexia, the question focuses on the "stopped eating" aspect and the resulting low potassium, making "imbalanced nutrition" the primary diagnostic focus. Choice C reason: "Adult failure to thrive" is a multi-systemic decline often seen in the elderly, characterized by weight loss, decreased appetite, and social withdrawal. While this patient has weight loss, the specific psychiatric diagnosis of anorexia nervosa and the acute electrolyte crisis make "imbalanced nutrition" a more precise and clinically appropriate nursing diagnosis. Choice D reason: "Disturbed energy field" is a nursing diagnosis related to the body's energy flow and is not grounded in the physiological data provided. Furthermore, this choice incorrectly labels the potassium level as hyperkalemia. The medical priority in this scenario is the physiological instability caused by starvation and severe hypokalemia.