My manager organized a team lunch for next week. The restaurant we will be going to is one where the only options are meat and fish. For medical reasons, I can't eat those things. In the past I was able to eat fish and I think that's the reason why the manager chose this restaurant (they always try to keep people's preferences in mind during these kind of events) without really informing me.
Now that everything has been organized and all, I think it is too late to ask for any changes. So my question here is: "Would it be unprofessional to go to a team lunch and not eat anything?"
I would still ask for something to drink so I have "something to do" while everyone is busy eating. According to other Q&As here, declining wouldn't be a good idea because these kind of team lunches can also be seen as team meetings.