In the starvation state, muscle decreases the use of ketone bodies, causing an elevation of ketone bodies in the bloodstream. The brain uses the ketone bodies for energy and uses less glucose, decreasing the need for gluconeogenesis and thus sparing muscle protein degradation to provide the precursors for gluconeogenesis. Red blood cells cannot use ketone bodies and must utilize glucose. Therefore, the use of glucose by red blood cells would be unchanged under these conditions.