Perhaps Lisa will be amused that the study took place at a certain Washington University in St Louis...
Here is another take on the quoted study, plus other info. This is from this link:
(This is a favorite site of mine plus also a "like" on facebook. He is a German man with a huge interest in researching diet & exercise stuff and interprets the studies with charts and graphs. English is his second language so just ignore the occasional wrong word)
If we take another look at the study outcomes, it is obvious that this increase in the transport of glucose across the intestinal border would in fact be the most likely mechanism to cause the (in this case appropriate) increase insulin response (more on that in the chapter on whether this is a good or bad thing). Previous studies in rodents also suggest that aside from the acute increase in GLUT-2 receptor expression, the chronic use of artificial sweetener has the ability to upregulate the expression of the "regular" Na-dependent glucose transporter and will thus have a persistent negative effect on what you could call the GI of everything you eat. Accordingly, the scientists speculate
"[...] that regular users of NNS [non-nutritive sweeteners] would have a higher glycemic response after an oral glucose tolerance test on the control day than irregular users and that the acute effects of sucralose intake would be blunted because differences between water and sucralose conditions would be smaller in regular than in irregular users of NNS." (Pepino. 2013)
In other words, chronic users won't be experiencing the effects that were observed in the study, but they will necessarily have a slightly increased insulin response to everything they eat (as long as they are healthy and not yet insulin resistance) irrespective of whether they consume it with or without non-nutritive (not just artificial) sweeteners.
Bottom line: ...The evidence simply is not there or as Renwick et al. put it in their review, there is "no consistent evidence that low-energy sweeteners increase appetite or subsequent food intake, cause insulin release or affect blood pressure in normal subjects." (Renwick. 2010).
Mars735 you might want to read the whole thing (it is multipart entries). I think the key is "in normal subjects." Is formerly obese a "normal subject"?
As for backing off, well, if you quit cold turkey you will keep wanting something sweet, I suspect. I think I would try backing off the Mio first, either by reducing the number of drops you are using or by say, 7 cups a day with Mio, one without for a few days, then 6 cups a day/2 without, etc. Also, look at new food combos to replace your sweetened foods (I'm assuming bars or shakes). Since you keep carbs at nearly ketosis levels, I'm not real clear on how to do it. For me, I can substitute 1/2 cup strawberries and 1/2 cup greek yogurt (sometimes 1c/1c) for strawberry wafers and honestly, I'm fine, plus it is just sweet enough. Another thought would be to go with fat (nuts, nutbutter) to replace an occasional sweet. That sometimes works for me for "lunch dessert". I also drink this sweet and spicy tea that often works, too.