Thing is that there really is no such thing as a healthy dry cat food. In fact it is the dry food that packs on the weight. "Indoor", "Weight Control", "Hairball" and any other foods that are packaged that way are just that. Packaged to appeal to
oursense of doing the right thing for our pet.
Cats are obligate carnivores. That means they need
meat. Not grain, corn, by products of meat, and everything else put into dry food to make it digestable for cats. We can't digest corn. Why would we think that a cat can?
Here are a couple of great sites to read. They will help you understand why cats need wet food (canned or raw) and the health benefits of it.
http://www.catinfo.org/
http://maxshouse.com/feline_nutrition.htm