The only time I've seen that show is when my fingers were too greasy from the potatoe chips to pick up the remote.
Seriously, though, it is a great motivator, but as a previous winner, who had gained some weight back after the show said, "losing weight was my job". He had no other obligations other than to lose weight. He had all day to work on it.
However, I once again agree, it is a great motivator, because most people don't need all day to exercise to lose weight.