I've forgotten to say that also meat, fish, milk and similar are dangerous because produce mucus and toxins.
The only natural food for human is fresh fruit. But it's important to understand that it needs and adaptation called transition diet (a journey that can last for years sometimes, depends on the physical body), because after years of mucus-food the body is too full of poisons. Fruits are very detoxicating food, but if the body is too full of poisons, it can may become ill or even die, suffocated by their poisons and toxins. So it needs to eliminate poisons and mucus only gradually, with a transition diet.