Ketone bodies are not utilized by

Red blood cells lack mitochondria, and hence the enzymes of the TCA cycle, electron transpo chain, b-oxidation pathway, or ATP synthase. This renders them incapable of utilizing fatty acids or ketone bodies as metabolic fuel. Consequently, red blood cells are completely reliant on glycolysis to generate ATP. Glucose enters red blood cells by facilitated diffusion, a process mediated by the glucose transpoer (GLUT1), also known as glucose permease.Ref: Harper&;s biochemistry; 30th edition; Page no: 691