Until the advent of refrigeration, the most important factor in a person's diet was availability; diets varied according to animal migrations and the growing seasons of fruits, nuts, and vegetables. Another factor in food selection can be religion. Muslims, for example, are forbidden to drink alcohol.
Diets vary throughout the world. North Africa, with many Muslims, and the Middle East have similar diets. A starchy food (see starch), such as rice, boiled and pounded yam mush, or cassava, is often accompanied by a spicy stew of fish or chicken with vegetables. Other popular dishes include curries, kebabs (marinated meat threaded on a stick and roasted), couscous (steamed wheat semolina), falafel (a spiced fritter), and yogurt. Many Asian diets are based on rice, which is often served with bite-size vegetables and meats accompanied by spicy seasoning. In Europe, bread is often the main starch, but Italy is noted for pasta, a nutritious noodle made from wheat and usually topped with a sauce, such as a small serving of cooked tomatoes garnished with cheese. In Scandinavia, fish in general, and herring in particular, are main staples of the diet.
Food has always been subject to cross-cultural influences, often as a result of colonization and migration of people. Thus, French influences can be seen throughout Asia, particularly in Japan and Indochina; Dutch influences in Indonesia and South Africa; and Indian influences throughout the Commonwealth of Nations. Certain foods, such as dumplings, are found in slightly different forms in all cultures. North American cuisine is an amalgam of Native American foods, such as corn-on-the-cob, and immigrant cuisines, including that of Africans.