At 7 months he's still growing a fair bit, so 5 crickets a day is okay, or an equivalent amount of other bugs (in very general terms, a large superworm or a roach counts like 2 cricket). You can start tappering off what he eats as he ages. Keep an eye on his body condition as a guide (fat pads, tail thickness). Also you could measure and weigh him periodically, to see if growth is slowing and thus so perhaps should food intake.