What hormonal condition promotes fatty acid oxidation during starvation?

• A. High insulin
• B. Low insulin
• C. High cortisol
• D. High glucagon

Answer: (B)

When starved, insulin falls, leading to a drop in the anti-lipolytic signal that normally keeps fat breakdown in check. This allows hormone-sensitive lipase to activate and adipose tissue to release free fatty acids into the bloodstream. Those fatty acids are then taken up by liver and muscle and oxidized to meet energy needs, with the liver also generating ketone bodies as a further fuel source. So the low insulin state directly promotes fatty acid mobilization and oxidation, making it the best explanation for why fatty acid oxidation increases during starvation. High insulin would inhibit this process by suppressing lipolysis, and while glucagon and cortisol play roles in coordinating the response, the defining hormonal condition enabling fatty acid oxidation is low insulin.