It is narrated from Sayyiduna Miqdam (may Allah be pleased with him) that I heard the Prophet (peace and blessings be upon him) say: The son of Adam does not fill any vessel worse than his stomach. It is sufficient for the son of Adam to eat a few mouthfuls that keep his back straight. But if he must (eat more), then one third for food, one third for drink, and one third for breathing.