Pescatarians eat fish, but not other kinds of meat. They will also eat other kinds of seafood and vegetables. This could be a healthy diet, because fish can contain a lot of omega-3 fatty acids. Pescatarians have lower risks of Type 2 diabetes, lower risks of cancer and lower blood pressure. It’s important to avoid fish with too much mercury. A lot of our oceans are polluted, and our fish could be contaminated as well. This diet means that you may not consume enough iron, vitamin B12, and vitamin D.