Answer to Question 1
Answer: Ablation of the LH produces aphagia and adipsia, which reflects cell damage rather than damage to axons of passage. Electrical stimulation of the LH elicits eating. Cells within the LH secrete MCH as well as orexin, two neuropeptides that induce eating.
Answer to Question 2
Answer: Animals vary in their capacity to store ingested energy as fat. Some animals are very efficient in that ingested energy can be stored as fat for later use, e.g., during a famine. Other animals are less efficient and waste some portion of ingested energy (e.g., thermogenesis or activity); these animals are less likely to develop obesity in times of abundant food.