While Dr. Charlie Seltzer of the Huffington Post is fairly neutral on the subject of diet soda, believing that its benefits and downsides are dependent on the individual, Allison Aubrey from NPR reports that diet sodas have been linked to changes in gut microbes and increase the risk of developing diabetes. Diet sodas are suggested as a calorie-free substitute for sodas but have connections to weight gain and metabolic syndrome.
According to Seltzer, diet sodas use a variety of artificial sweeteners like aspartame, sucralose and stevia. However, Aubrey reports that studies demonstrated that after exposure to these sweeteners, some people developed severe disturbances in their blood glucose and experienced reactions so severe they could have qualified as pre-diabetic. Other research has shown that artificial sweeteners make it difficult for the body to regulate sugar intake and create cravings for sugary substances, negating the benefits of diet sodas.
Seltzer also reports that some people react poorly to artificial sweeteners, experiencing headaches. Animal research links diet soda to cancer, though there is little human data to corroborate this claim. Seltzer concludes that while diet soda is not as healthy as the zero-calorie label suggests, there are people who benefit by drinking it to satisfy a sweet tooth and curb their hunger.