The word ‘fat' carries burdens of social, cultural and visual expectation, but also a historical one. Size is usually described in terms of bigger equating to better: from America, where the ‘Great Nation' conveys both vast and peerless, to the Indian subcontinent, where ‘big people' and ‘little people' refer not necessarily to physical attributes but to wealth and social class. Our history with this nutrient, which, along with proteins and carbohydrates, represents one of the three basic elements of our diet, has evolved alongside agriculture, religion, culture, medicine and now the modern media, as Christopher E. Forth tells us in his new book.