This diet works very well I have done it. Started in March and by October / November, had dropped 5 stones. Although it takes some serious commitment and will power to get started, once you have been on it for a while it is really easy. The basics behind it is that you completely remove the decision making process out of the diet. The only thing you choose is the flavor of your pack.
The hardest part is when you get back onto food. Trust me... been there... and hanging in there!! When the food comes back into the equation, it is much much more difficult because suddenly you have to make decisions. And it is not as simple as it seems. Those who have a weihgt problems will understand, the others won't.

Three other things.
First, Rich your dad won't be able to do the diet if he is diabetic .

Second, they only take people who have a MINIMUM of 3 stones to loose.

Third, those of you who want to try it and think they are man / woman enough to just walk in, take their sachets and just do it on their own at home, well just stop beeing narrow minded . The biggest part of the diet IS the 2 hours "chat" (which really are therapy sessions in a group of the same gender... so you won't be talking about knitting and periods with over reacting women... ). Once you accept it and actually participate, its absolutely amazing what t does for you.

That's it... that's my 2 pence added.