Hi,
I've been doing this diet for 2 weeks. I used to use Herbalife Formula 1, with which I lost 4 stone and I felt amazing but as I'm a student I couldn't afford to keep doing it so I started Tesco Ultra slim.
The shake works to curb your appetite and shrink your stomach, but I've been following this regime religiously and having 2 shakes made up with water and 1 healthy, low fat high protein and fibre meal in the evenings and I've put on 1 and a half inches everywhere!! This is nothing to do with my evening meal as I'm well aware of the nutritional content of my meals.
I would honestly just shell out more for Herbalife Formula 1, although its worth noting, in any diet like this, there is a lack of fibre which from personal experience has ruined my digestive system so make sure you're taking a fibre supplement every day.
I hope this helped you, I know 2 weeks isn't long but by this stage with Herbalife I had 3/4s of a stone.