The joy and sorrow of perks at work

At my workplace there are a lot of staff-appreciation lunches and holiday celebrations. about twice a month an officer will announce that lunch is being brought in for the staff - one day a Mexican salad bar, another day pizza, wings and salad, and a few Happy Hours at local restaurants. It's always so nice to hear, and then I feel the let-down because I cannot participate. If I ate that food at lunch time, I'd be fully distended within an hour and extremely uncomfortable until I got home. Such an emotional roller coaster. At least I can attend the happy hours, nurse a glass of wine for an hour, pick on apps, and leave before the pain sets in.
How do you all cope with social stuff? Especially holiday meals at other people's homes?

There are so many people who are on some sort of diet restriction or special diet due to medical issues, food allergies, etc. I like to socialize, so I either bring my own food, or more often, there are one or two things I can eat. Most people don't even notice....it is more you being self conscious. I was recently at a meeting and they brought pizza....I was in the middle of c.diff stuff and there was no way I was going near pizza. I just said, "No thanks, my stomach is acting a little funky," and no one thought anything of it. I've learned to try to stop feeling deprived and focus on the social aspects of the people instead of the food.