During Fasting or Starvation, the Brain

Question

During fasting or starvation, the brain:
A) converts endogenous fatty acids into β-hydroxybutyrate.
B) utilizes β-hydroxybutyrate from the blood stream.
C) utilizes amino acids for fuel from degradation of brain protein.
D) utilizes its glycogen stores as a first responding source of fuel.
E) all of the above.

Accepted Answer

During fasting or starvation, the brain adapts by utilizing β-hydroxybutyrate from the bloodstream as a source of fuel, which is a ketone body produced by the liver from fatty acids. The brain cannot convert fatty acids into β-hydroxybutyrate, does not degrade its proteins for fuel, and has minimal glycogen stores, which are not a significant source of fuel.