I work in a smallish office with not a lot of interaction between employees. The one time people seem to get together is for lunch. About once a week, the whole office orders pizza and eats together. I keep kosher pretty strictly and won't eat their pizza, even if it's vegetarian, but I end up feeling really awkward and anti-social. I bring my own lunch and eat with them, but it's not the same. Since none of them are Jewish and no one understands what I mean when I say I keep kosher, I'm worried that my co-workers think I'm snooty or even maybe that I have an eating disorder. What can I do to feel more included and less self-conscious?
Pass on the Pizza
Self-Conscious About Kashrut
If you don't act snooty about anything, including your eating habits, it's unlikely that your co-workers will think you're snooty. If you act snooty, kashrut or not, they'll rightly think you're snooty. Likewise, if you act self-conscious, they'll think you have something to hide; but if you behave with confidence, they won't.
It's worth making an extra effort to find common ground to relate to your co-workers on the rare occasions when you interact. I'm glad you make a point of sitting with them during these pizza lunches despite your discomfort, but maybe you can take things a step further. It sounds like an important piece of this is having your co-workers see you eating the same food that they're eating. Maybe once a month or so, you could take the lead on organizing the group lunch. If there's a kosher restaurant nearby, arrange the orders and delivery from there. If that's not an option, see if you can buy kosher sandwich fixings and set up a sandwich bar. If you're feeling really generous, you could cook something at home and bring it in for everyone to share. Or, if you don't want to go that far, make cookies and bring them in to accompany the pizza.
You could also consider preempting any questions they may have. I would advise against trying to explain the intricacies of kashrut. However, you could be ready to respond to those who question why you can't eat the pizza by saying something like, "Thank you so much for organizing lunch for everyone. I keep kosher, which means I only eat food that I prepare at home or that comes from a kosher restaurant, but I'd love to join you when the pizza arrives."
If a co-worker presses about what makes food kosher and you're willing to have that conversation at work, try to have it one-on-one. I've definitely been in situations where my eating habits have become the focus of the conversation for a whole group. I try to brush past it with something like, "There are a lot of rules of keeping kosher, but it's not that interesting of a lunch topic for everyone. What are your weekend plans?" When, inevitably, someone says, "Doesn't a rabbi have to bless your food before you can eat it?" or some other common misconception, answer honestly but succinctly: "It's not about a blessing exactly. It's about ingredients and preparation. What are your weekend plans?" You don't want to be dismissive, but you also don't want to be the center of attention, at least not about this.
Maybe you have some co-workers who are gluten-free or have food allergies or are on a diet, and you could bond about adapting your eating "habits." When there's something that sets you apart, you're far more likely to notice it than anyone else. Honestly, I doubt anyone spends too much time thinking about what you eat. If they do, it's probably because they're either genuinely curious or generally nosey about other people's business. Either way, be your personable, professional self. If you don't give them cause to suspect that something's wrong, they won't suspect that anything's wrong.