megarexia
n.— «There are also more general risks and dangers involved in body building, not least of which is the emergence of “megarexia,” a new condition in which the individual becomes obsessed with increasing the sheer muscular bulk of the body—the very antithesis of the anorexic body.» —by Simon J. Williams The Lived Body: Sociological Themes, Embodied Issues June 1, 1998. (source: Double-Tongued Dictionary)