Surgeons removed a sizable part of Tom’s stomach to prevent the spread of a cancerous tumor. Following a successful recovery, Tom’s reduced appetite for food is most likely attributable to his body’s reduced secretion of: a) ghrelin.
b) epinephrine.
c) leptin.
d) PYY.

Ghrelin

Explanation:

Ghrelin is a hormone that plays a major role in stimulating/increasing appetite and further increasing the intake of food and storage of fat, and that is why it is referred to as the "hunger hormone". Ghrelin is produced in the stomach, it performs its function by signaling to the brain to be hunger and hence result to increase in appetite; some amounts of ghrelin is also released by the pancreas and small intestine. Ghrelin is primarily regulated by the autonomic nervous system.

Therefore, since the surgeons removed a part of Tomae's stomach which eventually led to reduced appetite for food, then ghrelin secretion has been reduced.

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