SIgh......I've certainly seen all the 'evidence to the contrary', or at least a significantly representative amount.

This is the long and short of it: artificial sweeteners give taste, not satiety, so you won't be as full as you would if you ate sugar, hence may eat more. Also, if you overestimate the number of calories you're 'saving' using sweeteners, you'll undoubtedly end up eating more, and potentially gaining weight. It's the stereotypical "Ooh, I drank a diet coke instead of a real one, saved 200 calories, so I can have a donut!"

Conclusion: pay attention to EVERYTHING you're eating, keeping in mind that you DO have a precondition of 'how much food you need', and do so in a manner that consciously minimizes your biases. It's not that hard, but most people don't take such a holistic approach, and I've not ever seen it specified as a factor in the 'studies' on artificial sweeteners. So, the studies are correct, per se, but you and I can hopefully be a little smarter than that....it's pretty much a problem of overcoming internal bias by acting on as complete info as possible.