Hello,
I tried it a few years ago and it really worked for me. Up until then, everything I tried just left me hungry, tired, fractious but still fat. With the GI diet I felt full, could eat really tasty things and the weight fell off (I went from a large 18 to a 10 /12).
My skin improved and I slept loads better as well.
It was a bit of a pain in the beginning working out what to eat and when but I am so glad I did it.
I now try to eat mostly low or medium GI things although I am less strict about eating 6 times a day.
I thoroughly recommend it!