About the only study suggesting sweeteners could spike insulin was found in vitro rat pancreatic cells when coupled with glucose and done with direction transfusion (instead of ingested orally)
the data from extensive in vivo studies in human subjects show that low-energy sweeteners do not have any of the adverse effects predicted by in vitro, in situ or knockout studies in animals. 
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- Aspartame: neuropsychologic and neurophysiologic evaluation of acute and chronic effects . Am J Clin Nutr. (1998) Spiers PA, et al.
- Effects of oral ingestion of sucralose on gut hormone response and appetite in healthy normal-weight subjects . Eur J Clin Nutr. (2011) Ford HE, et al.
- Effect of the artificial sweetener, sucralose, on gastric emptying and incretin hormone release in healthy subjects . Am J Physiol Gastrointest Liver Physiol. (2009) Ma J, et al.
- Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels . Appetite. (2010) Anton SD, et al.
- Effects of carbohydrate sugars and artificial sweeteners on appetite and the secretion of gastrointestinal satiety peptides . Br J Nutr. (2011) Steinert RE, et al.
- Effect of aspartame and protein, administered in phenylalanine-equivalent doses, on plasma neutral amino acids, aspartate, insulin and glucose in man . Pharmacol Toxicol. (1991) Møller SE.
- Aspartame ingestion with and without carbohydrate in phenylketonuric and normal subjects: effect on plasma concentrations of amino acids, glucose, and insulin . Metabolism. (1990) Wolf-Novak LC, et al.
- Response to single dose of aspartame or saccharin by NIDDM patients . Diabetes Care. (1988) Horwitz DL, McLane M, Kobe P.
- Sweet taste: effect on cephalic phase insulin release in men . Physiol Behav. (1995) Teff KL, Devine J, Engelman K.
- Effects of artificial sweeteners on insulin release and cationic fluxes in rat pancreatic islets . Cell Signal. (1998) Malaisse WJ, et al.
- Sweet-taste receptors, low-energy sweeteners, glucose absorption and insulin release . British Journal of Nutrition. (2010) Andrew G. Renwicka,Samuel V. Molinarya.