Fresh meant and fish will not provide a balanced diet for your cat, as
they are very high in protein and low in other important nutrients, especially
calcium.
While it is true that cats are carnivores and that in the wild they eat
almost exclusively animal tissue, in that environment they will normally eat
a whole carcass, including the internal organs, bones, and stomach contents,
which provide many nutrients that are not present in lean muscle tissue.
It is possible to rear and maintain cats successfully on a fresh food diet
but you need to be very careful to add a variety of other foods to ensure
that a complete diet is being fed.