sustenance vs food

sustenance and food both are nouns.

Word	Noun	Adjective	Verb	Adverb
sustenance	Yes	No	No	No
food	Yes	No	No	No

As nouns, food is a hypernym of sustenance; that is, food is a word with a broader meaning than sustenance:

sustenance: a source of materials to nourish the body
food: any substance that can be metabolized by an animal to give energy and build tissue

Other hypernyms of sustenance include nutrient.

sustenance (noun)	food (noun)
the act of sustaining life by food or providing a means of subsistence	any substance that can be metabolized by an animal to give energy and build tissue
a source of materials to nourish the body	anything that provides mental stimulus for thinking
the financial means whereby one lives	any solid substance (as opposed to liquid) that is used as a source of nourishment