Food nourishes the body, but our relationship with food extends far beyond our need for survival. We use food choices not only to express our personal tastes but also, and perhaps more importantly, to declare our affiliation with certain groups to the exclusion of others. Thanks to a newly global system of food production, however, coupled with rising concerns about the nutritional value of the foods we consume and the impact of our increasingly sedentary lifestyles, the modern foodscape has become remarkably difficult to navigate. A single food item may, for example, be labelled with...