This is not true of stevia, which IS a naturally derived sweetener. Here a few reputable sources from which you can learn more about it

http://healthvermont.gov/prevent/diabetes/documents/DIA_Sugars_2pg.pdf
http://www.ndhealth.gov/oehd/Publications/Diabetes Notes Vol 1-Issue 2-Spring 2010.pdf
http://fnic.nal.usda.gov/food-composition/nutritive-and-nonnutritive-sweetener-resources

(in reference to a remark made on the healthvermont website: http://www.fda.gov/AboutFDA/Transparency/Basics/ucm194320.htm)

Yep, NOT true about Stevia. It's an herbal sweetener. Actually, I guess I should say it's partially true about Stevia simply because since it's starting to hit the market; they've been cutting it with other crap instead of using the pure form. Mostly because the FDA won't officially approve it for use as anything other than a herbal supplement so they have to add/take away certain things to be able to shelve it at local stores and get away with selling it as a food product. So, I always recommend avoiding "stevia" products such as Truvia because yes, they are no better than aspartame or Splenda.

BUT...get Stevia in it's true, herbal form, and it's fantastic! I get my a local health food/vitamin store. You'll find it with the vitamins and herbs rather than in the sugar aisle with food at those places (again it goes back to pure form can't be sold with or as a food product). It's pretty pricey at first glace but you only have to use so little of it that it goes a very, very long way. I buy a small 6 oz bottle and it's about $20 but it seriously lasts me for months and I use it in coffee every morning, with Greek yogurt, to bake with, etc. So it really does go a very long way.

It also has other super benefits to using it. One is that it improves oral health. This I've found to also be true I use to have issues with periodontis and would have to have my gums deep cleaned and "scaled" at the mere price of $1800 every 6 months along with the regular teeth cleaning. After I started using Stevia - you should see my before and after pics. This is the first time I've not had to have the stupid planing and scaling done for my family history of perio disease. It's so good for oral health, some herbal toothpastes actually put it in as an ingredient. Medical studies show it to help lower insulin and blood sugar levels better than anything else, it helps lower high blood pressure, and some other good benefits.

My hardest thing to give up in the chemical sweetener market was soda. I'm a soda junkie. But; they even make soda with stevia now instead of aspartame. HOORAY!