I think it's a very trial and error thing to be honest. I did it a few years back. I lost a stone in 2 weeks and it was fab. I'm thinking that was more the water loss than anything else. After then, i literally went back down to losing 1-2 pounds a week. (which is a normal calories controlled diet loss anyway) so I gave it up. As soon as I gave it up, the weight piled back on
I find it very expensive for a "quick fix"
On the otherhand, if you want the weight to come off and stay off then I would suggest a simple calorie controlled diet would be better. We as women (according to dietician) are allowed 1800 calories per day. She told me that if you cut this down to 1200, make sure you don't go over that, drink your 8 glasses of water a day etc and "try and do some excercise" you should see a 1-3lb weight loss each week. Works for me!
I don't know if you've heard of myfitnesspal.com at all? But it works pretty much the same as Slimming World (so I am told) where you can keep a track of what you each and work out all the calories/fat intake etc. It allows you to input all the excercise you do etc including carrying babies around and walking up and down those stairs countless times a day etc (things we all forget as excercise) those calories lost are then added to your daily allowed allowance so your 1200 calories may actually add up to 1600 calories etc for that day. The joy of this site is that it is FREE. There is a huge community on there too, plenty of forum subjects on how to lose weight etc.
As you can probably tell, I am on there and at the moment in the last 4 weeks, I have lost 7lb. I will be doing my next weigh in tomorrow so will see how much more I have lost in the last week.
Don't know if that helps at all? xx