In 1939, Life magazine wanted to reassure Middle America that baseball star Joe DiMaggio was a perfectly upright citizen despite his suspect Italian ancestry: “Although he learned Italian first, Joe, now twenty-four, speaks English without an accent and is otherwise well-adapted to most U.S. mores. Instead of olive oil or smelly bear grease he keeps his hair slick with water. He never reeks of garlic and prefers chicken chow mein to spaghetti.” It’s interesting to reflect that at one point in history eating spaghetti was seen as somehow anti-American (and, conversely, chicken chow mein was considered good wholesome Yankee food).
Food brings us together but, as the Life article reminds us, our diets can also divides us. From at least biblical times, dietary restrictions are a way of creating ethnic identity: if you can’t eat certain foods then it’s hard to leave the tribe. For this very reason, many ethnic slurs are rooted in food words. This is why Germans were called “krauts” (from sauerkraut), the English “limeys” (from the lime juice that sailors in the British navy drank to prevent scurvy), the French “frogs” (from the eating of frog’s legs), French-Canadians “pepsis” (Pepsi Cola used to dominate the soft-drink industry in Quebec), and Italians “spaghetti benders”. There are also the many variations on eater: watermelon-eater (for African-Americans), rice-eater (for Asians), bean-eater (for Mexicans), and curry-eater (or curry-muncher, for East Indians). This is partial list (taken mostly from the Wikipedia entry on ethnic slurs).
On the other end of the spectrum, one sign of cosmopolitanism is a diverse diet, as can be seen in many big cities. Historically, perhaps the most crucial decision made by the early followers of Jesus was to give up Jewish dietary laws (along with the requirement of circumcision). Prior to that, the Jesus movement was a Jewish sect; but once they could eat anything, the early Christians were able to spread their doctrine throughout the Roman Empire, eventually becoming the official religion of the far-flung state. An omnivore religion is well-suited for an empire, just as a restrictive diet works better for a tribe or small nation.