I did last year, and I lost about 10 pounds in one month. Once I got busy with summer activities, I kinda forgot about it, and didn't go back on. My son used it last year as well to help him trim weight for football. He was overweight for his age group, and needed to lose weight, so it helped him a bit as well. Overall, I like the WII Biggest Loser, I just need to get back on there in the fall when the weather turns for us.
WI#1 (-10) WI#6 (Vaca) WI#11 (-10)
WI#2 (-6) WI#7 (Vaca) WI#12 (0)
WI#3 (-6) WI#8 (Vaca) WI#13 (-3)
WI#4 (-2) WI#9 (Vaca)
WI#5 (-5) WI#10 (+6)