No matter what you figure out for food at the wedding, it’s so much better to go there with a full stomach. Just in case something goes wrong, or the meal isn’t what you were expecting, at least you ate before so you’re not STARVING. Trust me, you would rather eat twice than not at all. Especially if you’re going to be drinking - you don’t want an empty stomach!

Depending on your relationship with the couple, they may have already thought about you and planned something for you - and if you’re close with the bride or groom, it’s okay to talk to them. 

But if it’s someone you’re not super close with, I wouldn’t be comfortable adding another thing to their plate when it’s already a crazy time - so I would only do this if it was my best friend/close family member.

If number two doesn’t apply to you, you can call the venue in advance (so the couple doesn’t even have to be involved at all) and ask them if they can make something special for you. For example, they could make you a more basic version of what they’re making anyway, like chicken with no breading or sauces. 

If they say yes,  you should be good! The waitstaff should be aware when you’re there, and take care of you! If he says they can’t safely feed you, now you know, ahead of time - and have time to get food.

...especially if the chef says they can’t safely cook for you. That way you’ll have at least something to snack on - nuts, bars, etc are good options that are filling and will hold you over until you get home. 

If you’re comfortable, you could even bring a sandwich or something! People seriously aren’t very cognizant of what everyone else is eating anyway.