Plutarch Quaestiones Convivales 6.8.2

[2] But after we began to enquire after the cause of this disease, the first thing that puzzled us was to find out the reason why bulimy seizes upon those that travel in the snow. As Brutus, one time marching from Dyrrachium to Apollonia in a deep snow, was endangered of his life by bulimy, whilst none of those that carried the provisions for the army followed him; just when the man was ready to faint and die, some of his soldiers were forced to run to the walls of the enemies’ city, and beg a piece of bread of the sentinels, by the eating of which he was presently refreshed; for which cause, after Brutus had made himself master of the city, he treated all the inhabitants very mercifully. Asses and horses are frequently troubled with bulimy, especially when they are loaden with dry figs and apples; and, which is yet more strange, of all things that are eaten, bread chiefly refreshes not only men but beasts; so that, by taking a little quantity of bread, they regain their strength and go forward on their journey.