It seems like he is always hungry. I feed him 3 times a day, 1/2 to 3/4 cup dry per feeding. Black lab, 8-9 weeks old, about 15-20 lbs. Lots of snacks and treats between meals. He has been wormed and is healthy looking, not skinny. But it seems like he is always hungry, so I'm concerned I might not be feeding him enough at meal time. Any advice? Thanks!