Do zombies eat brains because they’re hungry for knowledge?

It was the evolution of zombie cinema. They began as living yet mindless people under voodoo spell. After Romero, they became the undead who ate flesh. In Return of the Living Dead, they introduced eating of the brain.

The idea of living dead is very old. Flesh eating living dead? Quite new. You will see in many zombie movies, they depict zombies eating any part of the flesh, not only brains. You then become one of them.