I have once before weaned myself off it and started drinking sprite/lomonade instead. Then after a particularly horrible string of closes at work (I work at maccas) started drinking it again for the caffiene. I think i might try the idea of weaning myself of onto coke zero and then going from there. Ideally i would go all the way through to just drinking water instead but the water that comes out of my tap here at home tastes horribble at the moment!!!
Buy your coke if can't possible live without it or substitue it, say you normally have 6 bottles a week, buy 4. Having your whole weeks diet at home meals you dont add, and once you are out thats it, you'll have to weight.
the idea of having my weeks worth of food at home is great, but i really am very lazy at the moment and don't know if right now i could bring myself to actually get up early enough to pack lunch and that to take to work and uni!
Thanks for all your suggestions guys, I'll keep you updated on how i'm going!!