PROPHET MUHAMMAD (ﷺ) said:
1) A human being fills no worse vessel than his stomach.
2) It is sufficient for a human being to eat a few mouthfuls to keep his spine straight.
3) But if he must (fill it), then one third of food, one third for drink and one third for air.

Yahya Al-Bakka' narrated from Ibn 'Umar who said:
"A man belched in the presence of the Prophet (ﷺ), so he (ﷺ) said: 'Restrain your belching from us. For indeed those who are filled most in the world will be the hungriest on the Day of Judgement.'"

It was narrated that ‘Atiyyah bin ‘Amir Al-Juhani said:
“I heard Salman, when he was forced to eat food, say: ‘It is sufficient for me that I heard the Messenger of Allah (ﷺ) say: The people who most eat their fill in this world will be the most hungry on the Day of Resurrection.’”