If you wanna go on Gillian's diet eat birdseeds and be unhappy with life.
Alternatively, eat healthily with wholewheat pastas, vegetables - and have a lot of food, but be healthy, full of energy etc. Also, you could join a dance class or something which will be social and also healthy.
Are you sure this isn't a wind up? I don't know anyone who would want to be on such a stupid diet and programme...