pf2e.fyi
From Pathfinder Lost Omens Impossible Lands, which isn't enabled.

Mental Sustenance

FEAT 1

You can sustain yourself with the power of your mind. You need only a single serving of food and water each week to avoid starvation or dehydration. You can hold your breath for an additional 5 rounds before running out of air.

Pathfinder Lost Omens Impossible LandsOGL