It may be similar to the fact that many people who start consuming “sugar free” products such as diet sodas find that they lose no weight. The sugar free product is just as bad for you as the sugar one. What you need to do is stop consuming the product altogether. In other words, why are you drinking sodas when good old H20 is better for you?
Diet sodas make you hungry and destroy your gut flora.
They might not have calories but they make you gain weight.