Though it isn't sugar, asparthame rewires the same reward mechanism. But it doesn't come with the other endocrinal feedbacks. Artificial sweeteners end up generating further craving for actual sources of sugar. Furthermore, people who drink diet coke just end up eating more calories as they overestimate their room for maneuver. At the end of the day artificial sweeteners will not help with leptin resistance, as the body craves more sugar. And it doesn't help with insulin resistance, most likely because you aren't losing weight and probably still has fatty liver disease.