Which endocrine disorder might someone have if they have an excessive appetite but trouble gaining weight?

• A. Hypothyroidism
• B. Cushing's syndrome
• C. Hyperthyroidism
• D. Addison's disease

Answer: (C)

Hyperthyroidism speeds up the body’s metabolism, so overall energy use rises. When metabolism is elevated, the body burns more calories even if you’re eating more, which can drive persistent weight loss despite an increased appetite. This pattern—hunger with difficulty gaining weight—fits hyperthyroidism best because the underlying issue is excess thyroid hormone (T3/T4) increasing caloric breakdown and energy expenditure.

In contrast, hypothyroidism slows metabolism, typically leading to weight gain or difficulty losing weight. Addison’s disease causes weight loss from cortisol deficiency but isn’t characterized by a compensatory increase in appetite. Cushing’s syndrome often presents with weight gain and fat redistribution, not weight loss with increased appetite.