This saying, speaks of the importance of forces being well-provisioned and eat properly if you want to perform tasks well.
in the 1858 work “History of Friedrich the Second, Called Frederick the Great” the saying occurred in the description of an unsuccessful military endeavor. They were stronger than Turk and Saracen, but not than Hunger and Disease. Leaders did not know then, as our little Friend at Berlin came to know, that “an Army, like a serpent, goes upon its belly.”