In this article, we are not going to talk about all the downsides of sugar (glucose, sucrose, fructose), or artificial sweeteners like aspartame, sucralose etc.  The web is plastered with articles and videos talking about this.

The bottom-line is,
a) we like things sweet…after all it is part of our natural tastes,
b) optimally, we would like a sweetener without the calories, or the insulin response,
c) ultimately it would be good, if the sweetener improved our ability to use sugar more effectively.

Let’s talk about Stevia! Stevia, is a naturally sweet plant – called Stevia rebaudiana. Its glycosides are 300 times sweeter than sugar, yet it has zero calories!  To be clear – Stevia has nothing to do with artificial sweeteners (Splenda etc.), and also has nothing to do with man-made sugar alcohol  products (Erythritol etc.) that create gastro-intestinal distress symptoms.
Here’s some interesting insights, from studies over the recent years on Stevia.

Stevia, is showing promising anti-hyperglycemic effects, in improving cellular insulin sensitivity (i.e. how cells suck in glucose, after being triggered by insulin).   In fact, some studies are even showing that Stevia mimics the effects of insulin, in improving glucose transport into cells.

Aside from the promise this holds out for diabetic and metabolic syndrome sufferers – these effects are interesting for further optimizing sugar transport efficiency in the endurance athlete.

References
1 .Stevioside from Stevia rebaudiana Bertoni Increases Insulin Sensitivity in 3T3-L1 Adipocytes.  Mohd-Radzman NH, et al. Dec 2013.
2. Steviol glycosides modulate glucose transport in different cell types.  Rizzo B, et al. Nov 2012.