Which brain region is the key regulator of hunger and energy expenditure?

• A. Cerebellum
• B. Amygdala
• C. Pituitary Gland
• D. Hypothalamus

Answer: (D)

Hunger and energy balance are controlled by a central brain region that integrates hormonal and neural signals to regulate feeding and metabolism. The hypothalamus sits at the heart of this system.

Within the hypothalamus, different nuclei work together to either promote or suppress appetite and to adjust how much energy the body uses. The arcuate nucleus contains neurons that stimulate hunger (via NPY/AgRP) and neurons that suppress hunger (via POMC/CART). It also receives signals from the body's energy stores, such as leptin from fat and insulin, which generally suppress hunger, and ghrelin from the stomach, which stimulates hunger. The hypothalamus then communicates with other regions like the lateral hypothalamus (promotes feeding) and the ventromedial hypothalamus (promotes satiety) to coordinate the overall response and regulate energy expenditure.

Other regions don’t serve this integrative role as their primary function. The cerebellum mainly coordinates movement, the amygdala processes emotion and reward aspects of eating but isn’t the central regulator, and the pituitary gland influences various hormones but does not itself serve as the primary controller of hunger and energy use.