Hadith - Keep ones' back straight

In the Name of Allah, the Most Gracious, the Most Merciful.

Abu Karima al-Miqdam ibn Ma'dikarib said, "I heard the Messenger of Allah, may Allah bless him and grant him peace, say, 'A human being fills up no vessel worse than his belly. Enough for a son of Adam are some morsels which will kept his back straight. If it cannot be avoided, then a third is for his food, a third for his drink, and a third for himself." [at-Tirmidhi]

Riyad as-Salihin (The Meadows of the Righteous) of Iman Mohieddine Annawawi 631-676. Chapter 144: "On visiting the sick, escorting the dead and praying over him and attending his burial and remaining at his grave after his burial " Hadith No 516.