Does the consumption of artificial sweeteners as a replacement for sugar increase the risk of diabetes or hyperinsulinemia? Have there been any clinical trials studying this?
There is a strong link between the consumption of sugar-sweetened beverages (SSB), obesity, and Type 2 diabetes, recognized by multiple studies, for example this survey (1).
This article (2) compares the consumption of SSBs with that of artificially sweetened beverages, and finds SSBs significantly worse. The study, however, is only a 10-week study.
This article (3) shows that one dose of sucralose does not cause insulin production.
This article (4) tends to show that ongoing use of artificial sweeteners does not control weight, but it is not conclusive evidence that it causes an increase in weight (self-selection issue).
This article (5), however, discusses a cohort where higher consumption of diet soda is associated with a significant increase of the risk of metabolic syndrome and the development of T2 diabetes. It is not, however, a smoking gun, because it does not prove causality but association (there could be self-selection: people at risk for metabolic syndrome may tend to drink more diet soda).
I would say that there is weak evidence of an association between the consumption of artificial sweeteners and diabetes risk. There is also some evidence that using artificial sweeteners is better than SSBs. On the whole, it seems to me that evidence is mixed at this stage.
For myself, I will continue -- carefully -- to use artificial sweeteners (sucralose in my case), but I will keep an eye on additional evidence when it comes up.
1: Malik, Vasanti S., and Frank B. Hu. "Fructose and cardiometabolic health: what the evidence from sugar-sweetened beverages tells us." Journal of the American College of Cardiology 66.14 (2015): 1615-1624.
2: Raben, Anne, et al. "Increased postprandial glycaemia, insulinemia, and lipidemia after 10 weeks’ sucrose-rich diet compared to an artificially sweetened diet: a randomised controlled trial." Food & nutrition research 55.1 (2011): 5961.
3: Ma, Jing, et al. "Effect of the artificial sweetener, sucralose, on gastric emptying and incretin hormone release in healthy subjects." American Journal of Physiology-Gastrointestinal and Liver Physiology 296.4 (2009): G735-G739.
4: Stellman, Steven D., and Lawrence Garfinkel. "Artificial sweetener use and one-year weight change among women." Preventive medicine 15.2 (1986): 195-202.
5: Nettleton, Jennifer A., et al. "Diet soda intake and risk of incident metabolic syndrome and type 2 diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA)." Diabetes care 32.4 (2009): 688-694.