There is one way around the sale of food items and group meals. Similar to the United Way adccvaoy, you are simply on a diet which you can follow with some tiresome details about your particular dietary food fetish. My go to food neurosis is natural foods I simply tell them I don't eat anything processed where I do not recognize the entire ingredient list as real food items. The best part of natural foods is that I can guitlessly eat kettle chips, Lays and Ruffles (only ingreedients potatos, oil, salt) while refusing all the crap that is being sold. No one likes listening to other peoples food issues, and mine works especially well because the few people who do like to obsess about diets ignore anything that does not adhere to their own cannon usually caloric restriction or atkins/south beach carb fears.