What is the main function of ketone bodies during starvation?

The primary function of ketone bodies during periods of starvation is to supply an alternative energy source for the brain. During starvation, the body shifts its metabolism from glucose to fat, leading to the production of ketones from fatty acids. The brain typically relies heavily on glucose for energy, but when glucose availability is low, such as during prolonged fasting or carbohydrate restriction, the brain can utilize ketone bodies as a more effective fuel source. This shift is crucial for maintaining essential brain functions and overall physiological stability during extended periods without food.

While ketone bodies do provide energy, they are not the immediate energy source in the same way glucose is. Stabilizing blood glucose levels and promoting muscle growth are not direct functions of ketone bodies. Instead, ketones play a crucial role in sustaining brain activity and function when glucose supply is limited, underscoring their importance in energy metabolism during starvation.