Diet sodas have long been marketed as weight loss tools. The idea is that they allow people to enjoy the sweetness of regular soda, but without all the calories and weight gain. Some scientists, however, are highly skeptical that diet soft drinks, which contain artificial sweeteners, actually deliver on those marketing claims. And evidence seems is mounting that diet sodas and artificial sweeteners may actually promote weight gain.
http://www.vox.com/2016/11/28/13764656/diet-soda-metabolism-weight-loss-obesity
