Park says that he used to drink juice made from boiled frogs in order to build his physique and this particular method of body building has started a trend in South Korea where they will eat fucking anything. Dogs, insects, frogs - if it has eyes, it's fair game. From the Guardian:
If someone offered me a glass of juice that they said had been made by boiling a frog I can without any semblance of doubt confirm that I would not drink it. I don't understand people who look at a frog and go 'aw man I could definitely eat that' and I have even less of a clue as to why you'd look at a frog and think 'oohhhhhh wait a minute.... we could drink that. You need to think 'outside' the box, bro. It'll be like Sunny Delight but healthier'. Why?! Just drink something normal like Ribena or contact lens fluid.