Why has my cat suddenly began throwing up?

Maybe your cat has an allergy to something, it may not even be the food he is eating. I wouldn't put him on meaty food I would keep him on dry food as if he has something wrong with his stomach then food in the tins could upset it more. I would take him to the vets to make sure he is ok. Does your cat go out if so maybe he is eating something he shouldn`t be eating outside? Hope he gets well soon.