They say that the flavour of Coke is hard to describe and when you are not drinking it you kind of forget how it tastes. True dat!
One of the greater physical steps to improving ones health, avoid soda-pop.
As aforementioned in this thread, look at those things that you 'can't' live without, and question, do you want to be under the influence of X substance? or a free being?
That goes for coke the drink and coke the not drink and all substances.
Maybe politely ask your mum if you could have more salad at dinner time, more toast and grains at breakfast time, and some hearty veggie sandwiches at lunchtime. Be supportive, let her know how much you love her cooking (if indeed you do). Red Cabbage apparently is quite nutritious antioxidant wise and is affordable, you can pick it up for little more than a dollar a head!
Namaste