Food is a culturally specific concept. In general, anything can function as food if it is not immediately toxic. But what is edible in one culture may not be in another. The concept of food is determined by three factors: biology, geography, and culture. Certain plants and animals are not consumed because they are inedible. Geography also plays a role, for example, dairy products are not part of the food culture in humid and tropical locations because it is harder to maintain cattle. Milk is often a taboo food in such cultures. Insects are not considered food in Europe and most of the United States despite attempts to introduce them in the late twentieth century. This is because there are few edible insects in regions with cooler climates. In Mexico, by contrast, insects are packaged in plastic bags, cans, or jars for sale. Cultural reasons for food taboos often have a location bias, i.e. unknown or exotic foods will be rejected as inedible.
Food avoidance most frequently relates to animal meat, since in most cultures human beings have an emotional relationship with animals they have to kill to eat. One of the few taboos of a vegetable origin is the prohibition against alcohol for Muslims and some Christian based religions.
Food may establish a cultural identity of an ethnic group, religion, or nation. Food taboos in a society function also as a means to show differences between various groups and strengthen their cultural identity. Not eating pork is not only a question of religious identity but also might indicate whether or not one belongs to the Jewish or Muslim cultural
References: Food Taboos: It 's All a Matter Of Taste. (204). Retrieved 10/02/2010, from http://news.nationalgeographic.com/news/2004/04/0419_040419_TVfoodtaboo.html Laws of Religion Judaism and Islam. (209). Retrieved 10/02/2010, from http://religion.atspace.com/index.htm Taboo Food and Drink. (2010). Retrieved 10/02/2010, from http://en.wikipedia.org/wiki/Taboo_food_and_drink#Pigs.2FPork