Cats need 41 essential nutrients (dogs only need 37), which seems like a lot but don't worry they are all included in complete cat food. Cats have a shorter intenstine than dogs so it is more difficult for them to digest plants and vegetables so there are less vegetables in a cat food than dog food.
Cats also need something called Taurine in their diets-this is an amino acid that keeps their heart and eyes healthy and helps cats have kittens. Cats can't make Taurine in their own bodies in the way some animals can so they need it in their food. Most Taurine comes from meat, poultry and fish so cats should never be fed as vegetarians, even if you are!
As they grow cats need different food:
Kittens: Have small stomachs so need small meals quite often.
Young cats: At around ten to twelve months kittens need to learn to eat adult cat food this should be done gradually over 3 to 4 days.
Adult Cats: If a cat stays indoors all day it needs less food than a cat that is able to go outside.
Pregnant cats: Need more food than other adult cats.
Old Cats: Cats over 8 years move less and aren’t so good at digesting their food so they might need food that is especially for older cats.
So think about this when helping choose a food for your cat.