What things are Buddhists not allowed to eat?
It all depends on whether the Buddhist a lay person or ordained monk, and what Tradition they are from. Zen monks are vegetarian and should not eat garlic/chives/onions/leeks. Tibetans don’t eat fish. Theravada monks eat whatever they are given unless they think that an animal has been killed specially for them. Lay people tend to make their own decisions about diet according to their circumstances.