Most of the dietary constituents that are essential to humans life are just as important for a cats well being.
Unlike us cats is a true carnivore,equipped to survive on a diet of other animals however they are needed and use in different proportions.
When a cat eat its prey it consumes not just the muscle meat, but also the skin, bones and internal organs.
There are no such thing as a vegetarian cat, all cats are carnivores and must have meat to survive.
But this doesn't mean that cats don't like or need to eat some form or fruits or vegetable matter.
Its just not possible to keep cats in good health on a vegetarian diet, they can be fed fish but this is not a natural food of the cats ancestor, and should be given in small amount.
The popular belief that cats need milk is just a myth.
In fact, cats can suffer from an intolerance to milk more frequently than to any other recipe that is likely to feature in their diet.
Siamese and similar breeds of eastern origin are especially likely to lack the enzyme known as lactase, which breaks down milk sugar known as lactose.
Cat actually have quite a peculiar metabolism.
For example, they need higher level of nutrition level of protein in their diet than dogs, and the protein must be of animal rather than plant origin, because this contain key amino acids that are missing in vegetables protein.
This amino acid known as taurine is used in the production of bile salts, as well as being vital for the functioning of the retina in the cats eyes, a deficiency of taurine is likely to cause blindness.
A shortage of taurine has also been linked with the condition known as dilated cadiomyopathy in cats.