Miqdam bin Ma'dikarib (May Allah be pleased with him) reported:
I heard Messenger of Allah (ﷺ) say: "No man fills a container worse than his stomach. A few morsels that keep his back upright are sufficient for him. If he has to, then he should keep one-third for food, one-third for drink and one-third for his breathing."[At-Tirmidhi, who classified it as Hadith Hasan].