Miqdam bin Madikarib said:“I heard the Messenger of Allah (ﷺ) say: ‘A human being fills no worse vessel than his stomach. It is sufficient for a human being to eat a few mouthfuls to keep his spine straight. But if he must (fill it), then one third of food, one third for drink and one third for air.’”
حَدَّثَنَا هِشَامُ بْنُ عَبْدِ الْمَلِكِ الْحِمْصِيُّ، حَدَّثَنَا مُحَمَّدُ بْنُ حَرْبٍ، حَدَّثَتْنِي أُمِّي، عَنْ أُمِّهَا، أَنَّهَا سَمِعَتِ الْمِقْدَامَ بْنَ مَعْدِيكَرِبَ، يَقُولُ سَمِعْتُ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ يَقُولُ " مَا مَلأَ آدَمِيٌّ وِعَاءً شَرًّا مِنْ بَطْنٍ حَسْبُ الآدَمِيِّ لُقَيْمَاتٌ يُقِمْنَ صُلْبَهُ فَإِنْ غَلَبَتِ الآدَمِيَّ نَفْسُهُ فَثُلُثٌ لِلطَّعَامِ وَثُلُثٌ لِلشَّرَابِ وَثُلُثٌ لِلنَّفَسِ " .
IbnMaja
Chapters on Food • Hadith 3349