Protien is a necessity. Carbs are also not all bad- looks for whole grains, oats, wheat, etc- refined sugars like sweets, sugar, white bread is what is bad and turns into fat. JB- you're doing the right thing. It's all about balance.
I have no idea what's in Red Bull- but I don't drink that. If I need caffiene, tea is best. Go for what is natural- even some energy bars are okay for you. Splenda is artificial sweetener- not good. Sometimes sugar free just means it has fake stuff which is even worse for you.