Stevia reduces insulin & glucose levels
 

It seems that stevia no only lowers glucoses levels but also insulin levels after consumption. Interesting.

"Consumption of stevia in preloads significantly lowered postprandial insulin levels compared to both aspartame and sucrose, as well as postprandial glucose levels compared to sucrose. "

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2900484/

One thing I have to wonder about here is the participant's prior use of artificial sweeteners, in rodents whether the animal has previously consumed a sweetener has a strong effect on the result of adding that sweetener to the animal's food.

And that's the key in this case. Further research required.