If your hosts offers you something you really don’t want to taste and you don’t want to be rude, say you are allergic to an important ingredient of that dish.
For example, if your hosts offer you some balut (fertilized duck egg), gently tell them that you are allergic to duck or amniotic fluid. And make sure you don’t eat roasted duck in front of your hosts later!
In many poor countries, offering a visitor meat is among the most flattering and respectful things a host can do. As such, claiming to be a vegetarian — even if it’s true — can be very insulting and confusing to your host.