From The Rotarian:
There is a new ritual in American life. It goes like this: Whenever you invite someone to dinner, you must inquire about any special dietary needs. Because today, it seems that nearly everyone has drawn a line around foods that cannot pass their lips.
This could be because of allergies, moral qualms, lifestyle choices, health issues, or simple preference. The person might be a vegetarian who eats fish, a carnivore who hates carbs, a glutton who avoids gluten, or a time bomb waiting to be set off by a nut. (Asking ahead makes for a more pleasant evening than calling an ambulance.)
Hospitalization aside, one reason for this shift has been the moralization of food. Our dining choices have become identity choices, a way of saying, “This is the kind of person I am,” or “This is the kind of world I want to live in.”
This is a luxury of our age. The hunters, villagers, and small bands of Homo sapiens in times past would have thought it extremely strange, and possibly hostile, to assert one’s preferences in this manner.