Hi Marissa, I don't know where you saw that the UK version of the game has been released, because from all of my research the only version that has been released is the Japanese one. Furthermore, the Japanese version of the game can only be played on Japanese Wiis, so even if you wanted to import the game, you'd need an import Wii as well.
I'm thinking that those "UK" versions of Wii Fit are scams. Unless you can send me some listings that I can check out? Looks like the rest of the world is going to have to wait while Japan gets ahead in the world of fitness.