In Greek mythology, Zeus did not eat anyone himself. However, it was his father, Cronus, who swallowed his children, including Zeus, in an attempt to prevent them from overthrowing him.
Cronus learned from Gaia and Uranus that he was destined to be overcome by his own children, just as he had overthrown his father. As a result, although he sired the gods Demeter, Hestia, Hera, Hades, and Poseidon by Rhea, he devoured them all as soon as they were born to prevent the prophecy.