Difference between Upkeep and Sustenance

Upkeep

Part of speech: noun

Definition: maintenance; the act or effort of keeping something in good repair

Part of speech: verb

Definition: to maintain (something) or keep it in good repair

Sustenance

Part of speech: noun

Definition: Something that provides support or nourishment.

Example sentence: I eat healthily as much as I can - meat, protein, carbs as well. I like my pasta; I like my rice. I like to have that sort of sustenance in me, because I'm always thinking of survival.