"He eats pork because he loves meat."
Translation:Hij eet varkensvlees, want hij houdt van vlees.
Some conjunctions in Dutch create a dependent sentence (called "onderschikkend voegwoord" in Dutch grammar), which has the verb at the end, and some (called "nevenschikkend voegwoord") create a normal sentence with the verb in the second spot. "Doordat" en "omdat" are in the first category, "want" is in the second.
"He" isn't the unstressed form of "hij" (though I can see why you would think that, since every other -ij pronoun does have an -e unstressed form). The unstressed form is "ie", but that is never written except in very informal style, and it's only used after another word. So you could say "hij eet varkensvlees omdat-ie van vlees houdt".
I'm a native speaker and "doordat" sounds wrong here, but I'm having trouble articulating the exact difference in usage between "omdat" and "doordat". http://taaladvies.net/taal/advies/vraag/598/omdat_doordat/ says that "doordat" is used only if human motivations don't play a role. In general "doordat" is used more rarely and usually you can also use "omdat" in places where "doordat" would be valid.