On Thanksgiving Day the hospital unit in which I work is having an employee potluck lunch. I don't have any issues with my coworkers, all of whom are friendly. Indeed, I joke and have other positive interactions with them throughout the day. However, I will not be attending this potluck for two reasons. First, I absolutely need my daily hour of solitude during which I eat lunch in my car in the fresh air, which enables me to recharge (I immensely look forward to this time every morning). Second, due to health and ethical reasons, I refuse to eat any food items without knowing and approving of their nutritional info and ingredients (indeed, homemade and restaurant-made foods literally make me sick to my stomach).

I know any coworkers who are in the break room participating in the potluck when I go in to get my lunchbox out of the refrigerator will ask me to join them. What should I tell them that will not offend them or make them think I dislike them, but that will enable me to quickly exit the room and proceed with my usual lunch-in-the-car therapy hour?

I hereby give many thanks in advance to anyone who is willing to share their thoughts on this subject!