Parashas Eikev · Passuk 8:10
When you have eaten your fill, give thanks to the ETERNAL your God for the good land given to you.
Torah Temimah points to Yerushalmi Terumot 1:4.
TT lemma: ואכלת ושבעת וברכת (unit 8 of 14).
Sefaria — Yerushalmi Terumot 1:4
English: They asked R’ Isi: What is the ruling for a drunkard regarding Birkat HaMazon? He answered: It is written, “you shall eat and be satisfied and bless” — even one who is drowsy/unclear from drink.
Custom (drunkard and Birkat HaMazon)
Birkat HaMazon can still apply in a state of heavy satiety from drink in a way prayer does not; details follow the poskim.