11. However, under ketotic conditions, the heart can effectively utilize ketone bodies for this purpose. 12. This is followed by " ketonuria " excretion of ketone bodies in urine. 13. Reduced insulin levels induce " lipolysis ", which consumes fat to produce ketone bodies . 14. During prolonged periods of fasting, ketone bodies serve as the primary energy source for the brain. 15. After fasting for 3 days, the brain gets 30 % of its energy from ketone bodies . 16. The production of ketone bodies is then initiated to make available energy that is stored as fatty acids. 17. When even the glycerol reserves are depleted, or sooner, the liver will start producing ketone bodies . 18. Each of these ketone bodies easily crosses the blood & ndash; brain barrier and enters the brain. 19. This is likely a result of ketone bodies providing an alternative fuel source to glucose for neuronal function. 20. Some scientists think ketone bodies may change the lipid membrane of brain cells to produce a lower firing rate.
