My husband and I have been dealing with this quandary for awhile as he's very intolerant of MSG and its dirty lookalikes. Catered food is so often low quality and usually covered in sauces - the last wedding we attended had fried chicken, BBQ ribs, coleslaw, and pre-dressed caprese salad - so nothing we felt safe eating. We actually sneaked out to a local Mediterranean restaurant we trust, got take-out lamb salads, and sneaked back. But we missed alot of the pomp (cake cutting, first dance) and it kind of sucked.
So what do you do in a situ where you're sitting at a table with a bunch of people and are supposed to be eating? I figure there are two issues here: how to get some food for yourself and dealing with going against social norms in a semi-public setting. We're both still a little self conscious about having to explain why we're not eating whatever.
I know fasting is an option. But sometimes it just rubs in the fact that our lifestyle is so removed from our current culture.