Cornaro’s recovery narrative is the origin of the doctrine: he reports that by about forty he was gravely ill from excess (stomach disorders and, by later description, complaints consistent with gout) and that adopting the spare fixed diet on his physicians’ advice restored him. It is a testimonial, the self-reported before-and-after of one person. It is recorded as untested because the recovery was neither controlled nor isolated from other causes: removing the excess that he says made him ill (heavy eating and drinking) could account for an improvement without establishing that the specific spare ration, or its quantity, was the operative factor. The recovery is the experiential kernel around which the broader life-extension claim was built.