I've been using Wikipedia as a research source for a book on which I'm working. One of their highlighted articles over the past ten days or so concerned Charles Domery. Here's an excerpt.
Charles Domery (c. 1778 – after 1800) ... was a Polish soldier serving in the Prussian and French armies, noted for his unusually large appetite. Serving in the Prussian Army against France during the War of the First Coalition, he found that the rations of the Prussians were insufficient and deserted to the French Army in return for food. Although generally healthy, he was voraciously hungry during his time in the French service, and ate any available food. While stationed near Paris, he was recorded as having eaten 174 cats in a year, and although he disliked vegetables, he would eat 4 to 5 pounds of grass each day if he could not find other food. During service on the French ship Hoche, he attempted to eat the severed leg of a crew member hit by cannon fire, before other members of the crew wrestled it from him.
In February 1799, the Hoche was captured by British forces and the crew, including Domery, were interned in Liverpool. Domery shocked his captors with his voracious appetite, and despite being put on ten times the rations of other inmates remained ravenous, eating the prison cat, at least 20 rats which had come into his cell, and regularly eating the prison candles. Domery's case was brought to the attention of The Commissioners for taking Care of Sick and Wounded Seamen and for the Care and Treatment of Prisoners of War, who performed an experiment to test his eating capacity. Over the course of a day, Domery was fed a total of 16 pounds of raw cow's udder, raw beef and tallow candles and four bottles of porter, all of which he ate and drank without defecating, urinating, or vomiting at any point.
There's more at the link.
I hadn't come across polyphagia (an unusually large appetite) before. It sounds like a most unpleasant disorder . . . I can't even imagine being so hungry as to want to eat a discarded human limb or 16 pounds of cow's udder!