In an attempt to try to get some more useful information about cat food....(I have an overweight Maine Coon), I found this great blog on petmd.com written by Dr. Jennifer Coates.  Petmd is full of useful information about cats and dogs.

http://www.petmd.com/blogs/nutritionnuggets/cat/dr-coates/2015/october/cat-food-for-real-cats-33249