"He likes food, so he eats."
Translation:Il aime bien la nourriture, donc il mange.
Because some "appreciation verbs" (aimer, détéster, adorer, préférer, apprécier, haïr ) naturally introduce generalities, always with definite articles: le, la, les. So, for example:
"I eat this chicken because I like meat" - "Je mange ce poulet car j'aime la viande" . "I like meat" is a generality, so we don't translate it as "de la viande".
"I love fries" - "J'aime les frites". "Les frites" are fries in general, (not some specific ones).
The same with our example: "He likes food" is another general statement, so "il aime la nourriture". Hope this is understandable.
It is "il aime la nourriture" because the verb "aimer" is an appreciation verb.
Verbs of appreciation (aimer, détester, adorer, etc.) always take the definite article for the item that is liked (loved, hated,etc.)
Look at the difference between an appreciation verb and a regular verb:
J'adore le chocolat (I love chocolate)
Je mange du chocolat (I eat chocolate.)
There's another thread above that goes into it even more.