The studies that tie diet soda with obesity are pretty wild. Some folks say the nutrasweet/aspartame is an appetite stimulant. That's a bummer.
There's also the behavioural aspect, like one study that had folks who ordered giant diet sodas also ordering giant burgers and fries (thinking it was ok, cuz after all they are cutting out calories from the soda, so some extra fries can't hurt, right?)
Artificial sweetners make me and SKnot very sick, and Nutrasweet in particular causes my mom to get ill. She's a diabetic and has a lot of trouble with dry mouth, so now she sips plain tea all day.
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson