How do you feed a House Gecko?

My house gecko only eats cockroaches. He likes to catch the cockroaches himself. When he is done hunting he goes back in his habitat for a drink of water. I live in a large multi-unit building, with a bug problem. That's why I got the gecko in the first place. Since the first week I had him I don't see bugs very often. He's fat too. If I drop a cricket in his habitat or even a roach, he won't take it because he's full from hunting.

A house gecko is an insectivore and will enjoy a variety of live feeders gutloaded and coated in calcium.