chelly the GI diet was one devised for diabetics to control their insulin levels, so basically eating the right kind of carbs that wont spike your blood sugar (and making you hunger).
It's basically just a common sense diet of what we would all think of as a healthy balanced diet, lots of fruit, veg and protein and switchingcarbs like white bread for wholegrain, white rice for brown, porridge instaed of a sugar cereal etc. If anyone was intrested your better to look into the GL diet which is a progression of the Gi but takes normal portion sizes into account.