It worked for him, but that sort of dieting is not recommended by medical professionals. The human body is not meant to live on an all-fat diet, not even when the fat comes entirely from its own reserves. Among other things it puts far too much strain on the gall bladder and significantly increases the risks of gall stones. And operations on a body in such poor condition are dangerous, too. Nature never intended for us to have such an excessive amount of fat reserves.