Fasting in France is understood either as a health or well-being practice or as a form of therapeutic hope, and it is becoming a significant social fact in constructing a new relationship to the body, to health and in the treatment of disease. According to some of its current promoters and advocates, in the Western world the practice of fasting goes back to the 19th century. The historical and social processes which characterize the new development of fasting within the medical arena since the 19th century have been nourished by primordial and recurring dissensions inscribed in a territorial struggle for legitimate medicine and academic science. In 20th century France, these dissensions have been reconfigured along with the emergence of new social spaces for fasting. They are permeated by different trends and still stand at the margins of medical orthodoxy. Starting from a media perspective towards fasting, we here investigate the ways in which the promoters and advocates of fasting give a symbolic impulse to the social, medical and scientific acceptability of fasting, while also enabling a “culture of hope” among patients.