Do you not find that sweetners make you really hungry? They have a similar effect on the brain as sugar, so your body is searching for the 'high' afterward, and therefore you feel hungry. I can't have them at all!
I am too scared to touch fizzy juice. I was a Pepsi max junkie before. I am actually astounded that it's not bothering me drinking water so I am going to stick with it incase I give myself a taste for it again.
I don't have it daily but always have one to hand. I find when I am in the mood to eat regardless I drink this. The flavour and the way it fills my tummy is satisfying and I lose the need to eat