Alot of cats like to be up at night instead of the daylight hours, (especially if they are bored during the daylight hours). Just leave plenty of dry food in their bowl, keep their "poopy-box" clean, and buy plenty of "scratch-posts" for him.
Maybe your cat is protecting you.. Feed him before you go to bed and he/she should stop, if not check out it further it may not be that he wants food. Maybe you don't give him/her enough affection and they try to make you play with them, Play with your cat a bit if the first solution doesn't work.
Don't give in, close the door, get a plastic mat like for wheely chairs in a office and put it where the cat scratches.. My cat used to do the same every night and actually didn't stop till we moved and trained her better
All you can do is get up an feed 'em. My cat gets me up at 5 am most times. Kinda sucks because dragging myself down a 6 foot tall loft bed half-asleep almost every morning Is very tiring. I usually feed him 3 times a day. Once as soon as I get up. Another when I eat lunch. Then as soon as I go to bed. Other times, I only feed him 2 times a day and then I have to go get up at 5 am and feed him. Sometimes he actually does have food and he just wants attention. There is really no way to make him quit. Just try to feed and attend to him before you go to bed. Good luck.
Do not overfeed your cat. If he has gotten in the habit of waking you up in the night, he has done so because he knows he will either get attention or some food from it. Instead of giving him these things, get a water spray bottle and put it on "mist" setting. When he makes noise or scratches to try to wake you up, spray the squirter. You do not have to actually spray the cat, the noise is generally enough of an unpleasant sound to make the cat give up on that tactic.
Can't you let the cat sleep in your room? That way he/she won't scratch at the door. He/she either wants to be with you, they want to go outside or they need a friend pet. He/she feels lonely when he/she wakes up at the night and that is why he/she is scratching at your door. Try leaving the door open if your cat is not too loud and you're able to sleep with her/him in the room. Else you need to make him/her feel less lonely another way. Try giving them outside access during the night if this is possible. If not, ask a friend to give you their pet for a few days, to see if a friend-pet will stop them from searching the door in search for your attention. If that works, buy a second pet.