Age range 8 to 12 Find out how pizza became the world's favourite comfort food in this nonfiction book, part of the How It Happened! series. Did you know that every hour, more than one million slices of pizza are eaten in the United States? But this cheesy flatbread had a long journey before becoming a global comfort food. This fact-filled book delivers the deep dish on pizza culture, history, and science. Whether you like thin crust or Sicilian-style, this book is one that pizza lovers won't want to miss!.