Book excerpt: Foods are changed not only by those who produce and supply them, but also by those who consume them. Analyzing food without considering changes over time and across space is less meaningful than analyzing it in a global context where tastes, lifestyles, and imaginations cross boundaries and blend with each other, challenging the idea of authenticity. A dish that originated in Beijing and is recreated in New York is not necessarily the same, because although authenticity is often claimed, the form, ingredients, or taste may have changed. The contributors of this volume have expanded the discussion of food to include its social and cultural meanings and functions, thereby using it as a way to explain a culture and its changes.