Wow, they haven't missed the point at ALL, have they?
Well done those chaps for completely misunderstanding the point of the Wii Fit.
You lose weight by adjusting your calorific intake:calorific usage ratio such that you burn more than you ingest. You can do this by eating less, working out to burn more, or preferably a combination of both.
Eating 5 times your daily carb requirement then doing ten minutes of Wii Fit will achieve fuck-all. As would the same behaviour with 10 minutes spent in the gym, or anywhere else.
The problem with this is that the researchers have tried to pretend that the Wii Fit either is, or is marketed as, the ONE SINGLE THING THAT WILL SOLVE YOUR WEIGHT PROBLEM. It's not, and Nintendo have never said otherwise. Stop giving morons publicity for moronic statements, for Christ's sake, it'll only encourage them.
Full Disclosure: The GF & I have had a Wii & Wii Fit for about 7 months, and in that time have found it very useful to help change habits. I've lost 2 and a half stone along the way and have gained a very useful morning wakeup routine. The majority of the change was to how often we eat and how much we eat. We could have achieved the same result with a scales, a notebook, some graph paper and a fitness DVD. The Wii Fit succeeds in simplifying the task of being aware of your overall food intake and physical condition, but it still requires people to be able to put the fork down in order to work.