I wouldn't worry too much about it. My friend's son is 11 and still doesn't like meat but her daughter is a carnivore. He may grow out of it or he may always not really like it. You can replace the protein with fish, pulses, eggs, cheese, yoghurt. I also give DS smoked tofu which i get from the health food store, its a very healthy source of protein and because its smoked all I have to do is slice it and dice it and he eats it with is fingers, he loves it. A visit to your health food store and a chat with them should be able to point you in the direction of some tasty things
xo