I free feed and Snow stays pretty thin. Her weight seems to change slightly (going by looks) from average to a bit on the thin side. She is also still very young at about 1 1/2. I think some cats, as people, just have weight issues. I also think age has to do with it, the older the cat, the more prone they are to being overweight. I could be wrong on that, just my opinion from experience over the years.