This paper analyzes the public fasts of two Italian “hunger artists,” Giovanni Succi and Stefano Merlatti, in Paris in 1886, and their ability to forego eating for a long period (thirty and fifty days respectively). Some contemporary witnesses described them as clever frauds, but others considered them to be interesting physiological anomalies. Controversies about their fasts entered academic circles, but they also spread throughout the urban public at different levels. First, Succi and Merlatti steered medical debates among physicians on the “scientific” explanations of the limits of human resistance to inanition, and acted as ideal mediators for doctors’ professional interests. Second, they became useful tools for science popularizers in their attempt to gain authority in drawing the boundaries between “orthodox” and “heterodox” knowledge. Finally, in the 1880s, Succi and Merlatti’s contest, the controversy around the liquids they ingested, and their scientific supervision by medical doctors, all reinforced their own professional status as itinerant fasters in a golden decade for that kind of endeavor. For all those reasons, Succi and Merlatti can be viewed as useful, epistemologically-active charlatans.