My cats have dry food ( a variety mixed together) and eat when they chose to. I have a few chunky monkeys here, but the majority are a good healthy weight. With the exception of Thumbelina who is multiple handicapped, everyone else eats dry all day, and wet once a day. Thumbelina never touches the dry food thankfully, otherwise she vomits profusely. But if the wet's run out overnight, I wake up to her drooling onto my face. Nothing like a wet gooey noserub at 6:30 AM! I'd try leaving extra dry food out before you go to bed, and maybe cut back on the daytime amounts. Or as others have said, switch to a light variety.