Sayyidina Miqdam ibn Ma’dikarib (R.A) reported that he heard Allah’s Messenger say, “A man does not fill a vessel worse than his belly. Enough for the son of Aad are a few morsels to keep his back straight. But, if it is unavoidable then let him apportion one-third for his food, one-third for his drink and one-third for his breath.”
[Ahmed 17186, Ibn e Majah3349]