Count me in the group hug.
My family are Polish and food is - what can I say - 'family'. You can't have one without the other. Try to pick out the least likely food to offend. I found if I make something in the dessert line, I can actually have some dessert (usually cheesecake). They all love cheesecake.
Mum is usually pretty good and includes a roast something along with all the other stuff - though she didn't last time - through me for a loop!
They will probably all be watching and trying to put food literally on your plate.
I'm not a really assertive person (silly me - I hate to offend people) and will not take a stand if it is not necessary. Not only do I hate to offend people, I hate to make a scene over nothing.
You could plan stategy - put food on your plate, play with it and spread it out to make it look like your eating
, or shovel into a napkin when no one looking
or b so busy helping load everyone else's plate you don't have time to eat.
If all else fails - smile, say thank you, then turn to your husband and say "try this dear, it's fantastic and pile it from your plate to his (what are husbands for if not this).
I'm sure you will do great. Don't stress. Enjoy your family.