JSF, your last links appeared to be good scientific studies, sans hysteria, so we are making some progress. The first link has some interesting info on the difference in brain response to sucrose vs sucralose. It posits a theoretical reason -- due to different levels of stimulation of particular portions of the brain -- why artificial sweeteners might not satisfy one's "sweet tooth" and lead to more consumption of sucrose in other forms. Over the years, I've read a number of clinical studies that have looked at this phenomenon and the results have been very mixed. My conclusion is that it probably occurs in some people and not others. I remember one study that showed that people who consumed aspartame over compensated and then consumed more sucrose than they would have otherwise. It was not a particularly well-done study and was kind of an outlier.
Here's the portion of the link in question that I found interesting: "(3) sucrose elicits a stronger brain response in the anterior insula, frontal operculum, striatum and anterior cingulate, compared to sucralose; (4) only sucrose, but not sucralose, stimulation engages dopaminergic midbrain areas in relation to the behavioral pleasantness response. Thus, brain response distinguishes the caloric from the non-caloric sweetener, although the conscious mind could not. This could have important implications on how effective artificial sweeteners are in their ability to substitute sugar intake."
Now, the other link was problematical. It did not indicate the type of artificial sweetener being studied, but one of the related links on the bottom seems to indicate that it was saccharin. This is the most questionable of all artificial sweeteners available in the U.S. Results related to it probably don't apply to the others. A number of years ago the FDA wanted to ban saccharin in the U.S. There was a public outcry. Congress pressured the FDA to backdown, and saccharin was allowed to be continued to used in the US for some purposes. Do you have a link to the full article rather than just the abstract?
Here's an interesting link on the subject, particularly toward the end in the section on quantity of consumption considered safe. Your one or two bottles of diet beverage a day -- which several posters had mentioned -- is nowhere near the upper limit:
http://www.fda.gov/Food/IngredientsPackagingLabeling/Food...