don't do it. It will screw up your metabolism for ever.
The weight loss is fab, but living on shakes and soups is not a healthy way to live.
And if you put on the weight again you will find it impossible to lose by any other means.
My mum did lighter life a year ago and lost 4 stone. She's put about three stone back on and she just simply can't lose it with ww and can't face doing lighter life again.
Seriously don't do it.
it's not natural, it's not healthy and you will pay the price both financially and health-wise.