The article linked below mentions a study comparing candy intake and sugary drinks. Those eating extra candy in their diet did not consume more calories overall, but those drinking extra sugary drinks did consume substantially more calories overall. Drinking calories fails to make one feel full it seems, so we go ahead and consume more calories.
Stevia is a good solution to this problem. Hot tea or iced tea with stevia and mint is a real treat, and adds very few colories to your diet.