You won't lose weight fast if you only do Yoga alone. However if you do STEP and Yoga together and also some strengh training (with weights), you will lose weight a lot faster than doing STEP alone. I am trying to lose some weight too. Actually that's not very accurate, I want to gain some muscle tone and lose the fat. I am planning to go to the gym regularly from now on. My problem is that I lack persistence. Hopefully I will be able to this time around. Wish me luck.