The Cambridge Diet (if you look up their forum) make a big thing about your body going into ketosis (which means in ordinary language that I'm burning fat for energy). They say it kicks in 4 - 10 days after starting living on 438 cals a day in the form of milk shake drinks.
I never did reach ketosis with the CD,but according to the ketostix I bought to check, I am definitely in ketosis now. But maybe that is this virus and lack of fluids.
Drink drink drink is my motto for this weekend