To help fuel his way to a record Olympic 18 gold medals,  swimmer Michael Phelps eats over 12,000 calories a day while training and competing. Presumably, Phelps doesn't wolf down all of these calories in one sitting.

Furious Pete, a competitive eater and YouTube personality, most certainly did consume over 12,000 calories in one giant meal.

Watch him take the Michael Phelps Diet Challenge below.

Wow. Talk about a glutton for punishment. We were cringing and clutching our gut by the time he got to the large pepperoni pizza and he still had a kilo (yup, he's Canadian) of pasta to go.

Impressively, 'Furious Pete' emerged from the stunt seeming none-the-worse-for-wear. As for the just retired Phelps, he better really pare down his diet or run the risk of quickly becoming the "Whaleman."