Atkins cites research from Harvard Medical School in DANDR Showing that brain tissue prefers ketones to glucose for fuel.
I think he'd laugh and shake his head at that statement. Think about it, lots of people fast for different reasons and their brains continue to function on ketones just fine.
The body can convert protein to glucose, whether ingested or taken from muscle tissue. But it is slower and less efficient than insulin-glucose.
This is not the first time something idiotic has shown up on MSNBC