Ketones are essential for providing the brain with fuel when glucose is scarce, acting as a temporary support system to keep the brain functioning until the next meal. Hunter-gatherers' ability to rely on fat stores and ketones during periods of minimal eating demonstrates the vital role ketones play in survival. Contrary to popular belief, weight loss on the ketogenic diet is not due to efficient fat burning but rather because the body wastes fat when in ketosis, leading to weight loss.