"Sometimes it's not the most fun conversation," she said. "People want to know what I do and what I'd eat in this or that situation. The skeptics think you need meat to be healthy and to drink milk for calcium."

During the holiday meal, Diehl hopes the meat doesn't come to rest in front of her, but is happy to pass it along to the next person. "Each person is in their own place," she said. "I'm not going to eat the turkey, but it's OK if you do."

What some call the "mixed-diet table" is the norm these days in the Bay Area, home to perhaps the country's most diverse group of eaters. If 20 years ago vegetarians sat down comfortably at the mainstream table, today's guests are likely to acknowledge that they're members of every dining splinter - vegan, raw food-ist, locavore, flexitarian, pescatarian, lacto-ovo vegetarian, organic fanatic, allergic to gluten, nuts or lactose.