<prompt> In prolonged starvation the main energy source of brain is:GlucoseKetone bodiesFructoseFatty acids  <response>: STARVE FEED CYCLEDivided into 5 stages:Well-fed state 14 hours after foodEarly fasting 416 hours after foodFasting 1648 hours after foodStarvation 23 days without foodProlonged starvation 5 days without food. 