This book explores contemporary worries over eating through the lens of the history of science and medicine. It shows how appetite, once a matter of personal inclination and everyday life, from around 1750 became an object of science, something to be managed by knowledgeable experts. At the same time it traces the disturbing story of how forms of troubled eating once seen as symptomatic of many illnesses emerged as independent diseases called “eating disorders.” The study begins by examining the traditional view, upheld by physicians and philosophers for centuries, that individual appetite was the surest guide to healthy eating. It then shows how investigators in diverse disciplines began arguing that eating and digestion were processes comprehensible and manageable only by science. The study also shows that new claims about the fallibility of appetite and the necessity of scientific guidance of eating choices prompted fierce disputes between mechanists and vitalists, experimentalists and bedside physicians, localists and holists, and instinctivists and anti-instinctivists, struggles over appetite and eating that have never been resolved. The author concludes that, far from solving what many called the “mystery” of appetite, centuries of research into its “normal” and “pathological” functioning have shown that appetite, like love and other deeply human realities, is extraordinarily complex and not readily susceptible to manipulation by self-styled experts. Restoring respect for appetite would help, the study concludes, to allay its proliferating discontents, the eating anxieties that beset ever more individuals in our time.