It is narrated from Sayyiduna al-Miqdam bin Ma'di Karib (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The son of Adam has not filled a vessel worse than a stomach. A few morsels that keep his back upright are sufficient for the Muslim. If it is unavoidable, then one third for his food, one third for his drink, and one third for his breath."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17779