This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Physiology
Leptin is decreased in all except 
Select and explain. 
A. Androgen, B. Exercise, C. Obesity, D. Starvation
C: Obesity
Answer: C: Obesity 
Explanation: In obesity, despite the presence of elevated leptin concentrations, which should reduce food intake and body fat, obese patients appear to be insensitive or resistant to leptin.