Italian pizza, 1990s.
© Science Museum / Science & Society Picture Library
Modern pizza evolved gradually since the ancient Greeks ate a flat baked bread with toppings called plankuntos. Tomatoes were brought back from the New World by the Spaniards (although they were initially thought to be poisonous), and Mozzarella cheese made from Indian water buffalo milk was introduced to Italy in the 18th century. Simple pizzas had been made in Naples since pre-Rennaisance times, and in the early 19th century it became a popular fast food, initially sold by street traders who carried small tin stoves on their heads. Pizza is much maligned as junk food of low nutritional value, but if made with fresh ingredients, the combination of bread, cheese, vegetables and meat represents the main food groups required in a balanced diet.