I do not believe in the effect of Wii Fit either, but coincidentally i have lost 30 pounds since i got Wii Fit. I think the main thing is that it confronts you with your own weight and sets targets for weight loss.
I don't use Wii Fit very often anymore, but still take it out from under the counch once every 2 or 3 weeks. Which means if you add up all the time on Wii fit i have spent, well, there are only a few games on the Wii which i have spent more time on.
(P.s. i just wish nintendo or TP's would take more advantage of the 20 million user base of Wii Fit. Especially since the average balance board game has sold close to a million copies)
Member of the Pikmin Fan Club







