Typically the TV goes off during dinner in most situations or switch it to one of the radio channels (in the case of cable/satellite). It depends on the formality and the household. It's often left on and can be seen at my sister's house, which is fine by me. I think if it was that disturbing, I would ask to turn it off or change the channel during the meal, turn down the volume, or sit someplace where it isn't so easily seen. Was the sole purpose of the day to do the marathon, because this would be a time to skip a gathering if the show is not to your liking. Otherwise, I see nothing wrong with turning off the TV during the meal or finding something a little more suitable. You can explain to the host that you are highly sensitive to this particular show and cannot manage watching it, in which case, I would hope they could comply for you, but again, if it was a "movie marathon day," which was part of the agenda, then you probably should plan on just not attending.
I don't get typically get turned off my food from icky stuff. It just doesn't bother me, and while sad, it wouldn't be that disturbing to tolerate it during dinner or if that's what's on during my visit. I would hope there is some conversation and I can avoid the programming, but when the purpose is to watch the show that I am really, really not interested in, I would probably just not go or only stay for a short while.