Just a thought -- make sure that your water intake continues to remain high as well. The thing w/ diet soda is that even tho its got the no cal sugar and all that, it tends to make you want more, more hungry, etc. I also notice a helluvan aftertaste from too much Nutrasweet. And I specifically don't like Diet Coke w/ Splenda. So don't let that diet soda become a replacement for your water intake and frankly I'd suggest make sure you at least drink an extra 16 oz of water for every diet soda you drink just to flush it out.
Someone told me it was the caffeine in diet sodas that causes hunger. It is the sweet syrup in the soda that causes an addiction-But drinking iced tea with diet sugar does not increase hunger or water retention, and gives a more satisfying feeling.