One of the highlights on Huffington post website recently:
" ... one strange thing about diet soda is that the people who drink it are actually more likely to have larger waist sizes (a measure of belly fat) than those who drink regular soda. Diet soda drinkers are also more likely to have type 2 diabetes and metabolic syndrome than people who didn’t drink diet soda at all." 
There is a clear correlation between obesity (expressed as change in overweight and obesity prevalence since 1962) and the change in per capita soda availability since 1962. This includes the consumption of both artificially sweetened beverages and sugar-sweetened beverages.
Many studies showed that the risk for metabolic syndrome, type 2 diabetes, hypertension, and coronary heart disease is increased with consumption of artificially sweetened beverages.
The scientist are trying to explain why.
Artificial sweeteners can increase the rate of absorption of glucose in the intestine,
Long-term (2 weeks) consumption of a high-sugar diet or of artificial sweeteners leads to an increase of glucose transporters in the intestine. The latter effect was shown for sucralose, saccharin, and acesulfame K. 
Functional MRI (fMRI) studies show that the human brain can distinguish between sugars and artificial sweeteners. This result would seem to undermine the hypothesis that artificial sweeteners confuse the body's link between sweetness and calories and lead to metabolic derangement. 
Routinely consuming artificially sweetened beverages changes brain response to sucrose or to artificial sweeteners in some regions, which relate to change in ingestive behavior. In imaging studies of the human brain, sucrose activates dopaminergic midbrain areas involved with reward, but sucralose does not.
Through systematic investigation of this effect, the researchers found that inside the brain's reward centres, sweet sensation is integrated with energy content. When sweetness versus energy is out of balance for a period of time, the brain recalibrates and increases total calories consumed.
There is also a "permission" effect. When people know that they have consumed a noncaloric beverage, they may give themselves permission to compensate by over consuming other foods. The calories saved by forgoing a 12-ounce can of sugar-sweetened soft drink (about 150) are almost insignificant when traded for a large order of french fries (about 500). And that's before you add ketchup, at 15 calories per tablespoon.
The researchers also showed that calories consumed in liquid forms are less likely to produce satiety and more likely to be over consumed than calories in solid foods.
We cannot discount the adverse effects caused by excessive consumption of other additives. Many of the disease causing effects attributed to artificial sweeteners are symptoms of excessive caffeine consumption. And a lot of the effects of soda is related to toxic effects of phosphoric acid on the bone health, absorbtion of nutrients and minerals, and deleterious effect on the gut microbiome.
Artificial sweeteners found to promote hyperactivity, insomnia and decreased sleep quality – behaviours consistent with a mild starvation or fasting state, and contribute to increase calories consumption. 
The other, less expected data :
pregnant women who use high-intensity sweeteners incur risks of premature delivery;
ingestion of sweeteners in large quantities contributes to cancer in mice, and associated with increased incidence of lymphoma in humans;
potential diabetogenic effects of artificial sweeteners through microbiota.
And of course we were led to believe the opposite.
University of Sydney researchers have confirmed widespread bias in industry–funded research into artificial sweeteners, which is potentially misleading millions by overstating their health benefits. This new comprehensive review of artificial sweetener studies reveals that reviews funded by artificial sweetener companies were nearly 17 times more likely to have favourable results. Their analysis shows that the claims made by artificial sweetener companies should be taken with a degree of skepticism, as many existing studies into artificial sweeteners seem to respond to sponsor demands to exaggerate positive results, even when they are conducted with standard methods. 
PLEASE, PUT THAT CAN OF DIET SODA OR DIET SPORT DRINK
AND POUR YOURSELF A GLASS OF PURE WATER!!!
For more information on healthy approach to yourself please contact Dr.Koganski's office by calling 1-215-750-7000, or going online www.newtowninernalmedicine.com
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Margolskee RF, et al. T1R3 and gustducin in gut sense sugars to regulate expression of Na+-glucose cotransporter 1. Proc Natl Acad Sci U S A. 2007;104:15075-15080
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Mandrioli d, et al.Relationship between Research Outcomes and Risk of Bias, Study Sponsorship, and Author Financial Conflicts of Interest in Reviews of the Effects of Artificially Sweetened Beverages on Weight Outcomes: A Systematic Review of Reviews. PLoS One. 2016 Sep 8; 11(9) : e0162198. doi: 10.1371