We use fat to coat our nerves — just like the plastic on an electric cable. It is this coating that makes us such fast thinkers. Some of the most important hormones in our body are made out of fat, and every single one of our cells is wrapped in a membrane made largely of fat. Such a special substance must be protected, and not squandered at the first sign of physical exertion. When the next period of famine comes — and there have been many over the aeons — every gram of fat in that paunch is a life-insurance policy. Our small intestine also knows the special value of fat.
