It is believed that food like non-veg or any food that creates mental imbalance is not to be taken by spiritual practitioners. Why it is like this? If I am a spiritual person that means I can’t even eat what I want?
I think it depends on you and it’s different for every person. Real spiritual progress doesn't require any special type of food. What is important is that you are mentally strong for meditation. We should listen to our body and eat according to our body needs.
As we all know we all are part of food chain. If every organism on earth becomes spiritual then how could life remain in balance? And most importantly some no-veg foods like egg and fish are important source of animal protein.
If your religion says something than it has to be something correct in it. Vegetarian food is pure and gives positive energy. It has everything in balance for being well, nothing less and not too much of anything.