Can artificial sweeteners cause weight gain?
Recent research shows consuming food or drink containing artificial sweeteners may lead to weight gain and obesity.
The research found that using artificial sweeteners in rats resulted in increased caloric intake, increased body weight, and increased adiposity. These results suggest that consumption of products containing artificial sweeteners may lead to increased body weight and obesity by interfering with fundamental homeostatic, physiological processes
So if trying to lose weight or avoid putting more on, it may be better to avoid products with artificial sweeteners.
See article by Swithers SE. A role for sweet taste: calorie predictive relations in energy regulation by rats. – Behavioural Neuroscience – 01-FEB-2008; 122(1): 161-73