This article addresses the question of why dieting, health, and the care of the body have come to play such a central role in our daily lives, and explores the relationship of these practices to the emergence of obesity as a social and health problem. Messages urging people to regulate their food intake and get more exercise in order to avoid obesity conflict with warnings that anorexia and bulimia are among the possible consequences of overly strict diets and excessive physical activity. The relationship between diet, beauty and health has been appropriated and re-elaborated as a marketing strategy with wide-ranging cultural consequences. "Being on a diet" is no longer only a matter of biology, nutrition, medicine or science; it is also about culture, politics and society.