I would also get hold of a copy of this book:
Hardback - Your Cat: A Revolutionary Approach to Feline Health and Happiness
Paperback - Your Cat: Simple New Secrets to a Longer, Stronger Life by Elizabeth M. Hodgkins
Your Cat: A Revolutionary Approach to Feline…Amazon.co.uk: Elizabeth M. Hodgkins: Books
Elizabeth is a US vet who used to work for the pet food industry and is a feline nutrional specialist.