Overeating

Imam Amir al-Mu’minin (peace be upon him) said:
"There is no health with gluttony."

(We say: Gluttony refers to Excessive eating or drinking, especially when someone eats far more than they need, purely out of desire or habit — not necessity.)

Imam Ali (peace be upon him) said:

"Whoever increases his fullness, his belly will burden him; and whoever is burdened by his belly will be veiled from intelligence."

In simpler terms:
Overeating leads to heaviness, and that heaviness clouds the mind.

Imam Ali (peace be upon him) said:
"Wisdom and a full belly do not go together."

Imam Zayn al-Abideen (peace be upon him) said:

"The one who is wise about Allah, fearful of Him, and acts for His sake — trains his soul and gets it used to hunger until it no longer longs for fullness. Just as racehorses are kept lean to win the race."

The Prophet Muhammad (صلى الله عليه وآله) said:

"Glad tidings (Tuba) to the one who remained hungry, folded his stomach (restrained from food), and was patient — they are the ones who will be full on the Day of Judgment."