Cambridge diet for just over a stone

Hi, I am thinking of doing the cambridge diet, but have a few questions that I thought you guys might be able to help me with. Here goes:

Is it worthwhile if i want to loose just over a stone?

How much is the initial outlay to start the diet?

Where you lose the weight so quickly, do you put it straight back on plus some?

Thanks in advance guys xx

Hya

hi im thinking of going my self and would love to here and know if it works many thx nicky