I assume Stevia at least biodegrades, I hard that splenda has started to pop up in the water supply over the world.

http://naturalsociety.com/sucralose-...rinking-water/

Two sources there. One of them,"Mercola.com" is not well-sourced and is a nutrition site which appears to have axes to grind. The other links to a legitimate source (an abstract from Environ Sci Technol. 2011 Aug 31. Epub 2011 Aug 31. PMID: 21879743) which indicates that a few hundred PPB (parts per billion) have been found at some US drinking water treatment plants (not "all over the world") without any support for claims of it being unhealthful.

Here's a hint: if you can't digest it, it goes through you. Like anything else.

Diet soda is far, far, far worse than regular soda.

I had a morbidly obese co-worker who justifed her 6 packets of Stevia in her Mcdonalds unsweetened jumbo sized iced tea by saying it is "natural." Around other people she didn't eat much, but I once caught her glimpse of the backseat of her car covered in Mcdonalds bags.

Got any peer-reviewed science to support that?

At 120-200 calories per 12oz serving, pretty much all from HFCS in one case is a known bad both for caloric and glycemic reasons.

The amount of artificial, non-nutritive sweetener is roughly 1/250th-1/1000th as large to produce the same sweetness, and the caloric impact is negligible. The understanding of the glycemic impact is less clear, but even there being merely "as bad as" the 30+ grams of sugars per serving is a relatively high bar.

Meanwhile, there has been plenty of research done on the pharmacology of aspartame, the weakest of the common artificial sweeteners (eg with 125mg in a 12 oz diet coke or about 1/250th of the amount of HFCS) and it is pharmacologically inactive at the levels of normal consumption:
http://www.fitday.com/fitness-articl...fe-levels.html
The newer sweeteners (Sucralose -- not commonly used in diet soda -- and Acesulfame Potassium -- which is typically used in MUCH lower quantities as a second sweetener to block aftertaste, along with a Aspartame) have much shorter track records, and less biomedical research on their safety, but they are also much stronger sweeteners and are used in lower doses.

Meanwhile, your coworker's other eating habits (or alleged eating habits) offer a much better explanation for their obesity.

http://www.naturalnews.com/033110_di...ight_gain.html
http://healthland.time.com/2011/06/2...on-to-dieters/

Both of those articles point to the same study.

While that study does raise a good deal of concern about the limited value of diet sodas in weight loss, it does NOT support the claim that they're WORSE than normal, sugar-containing soda as CBear attested.

The inferences made based on that study support the concern that diet sodas are bad for you in glycemic terms (and perhaps behavioral terms as well); on the other hand, the bad glycemic impact of sugar-containing soda is already well-established, and they present no evidence that diet sodas are in any way worse (they don't appear to compare to sugar-containing soda at all.)

The only sugar-vs-fake sugar comparison given in either article is an off-hand reference to a study referring to saccharine in rats, which then links to an article that doesn't mention that study -- not very helpful.

I Put My Money on Stevia
 

To me, the bottom line is this: artificial sweeteners (aspartame, sucralose, saccharin, etc.) do not exist in nature but rather are created through chemical processes. (Although aspartame, at least, is composed of 2 amino acids that you get in many natural proteins anyway.) I'm not excessively concerned about them because I have some, but not total, faith in the scientific studies clearing them for human consumption. However, with people guzzling tons of diet drinks, etc., that are sweetened with these artificial sweeteners, it may yet come out that they have long-term ill effects. Therefore my preferred sweetener is stevia. It is NOT an artificial sweetener. It's extracted from a plant rather than being synthesized using inorganic chemicals. People have been consuming it for centuries. So to me it's clearly the least of all evils, and I wish it was more widely used and easier to purchase in drink flavorings.

That's my 2 cents.

It may not be as widely used as the others, but I see many cans and bottles of stevia sweetened drinks in one of my local grocery stores.

I went through 60 days of Whole30 to "tame the sugar dragon". I've lost 20 pounds by avoiding sugar, and artificial sweeteners seem to stimulate that craving. So I avoid them. I miss sugar. But I don't miss weighing 20 pounds more. I just got a replacement knee 18 days ago and I'm back on my feet and almost performing normally. The key, according to my orthopedist, is maintaining a healthy weight. My observation, from sitting for hours in his waiting room, is that most of his other patients do not. And many of them are drinking diet sodas while they sit there.

What makes people fat is consuming more calories than they expend. Period.

Blaming overweight on diet soda is overlooking the true reason.

True, but you have to start somewhere with cutting calories (and expending more). Cutting out fizzy drinks and replacing with tap water seems a good place to start for your own health and that of your wallet.

The biggest "problem" with non-nutritive sweeteners is that people think they're all they need to do to lose weight, or even take them an excuse to eat worse in other senses. For that matter, for those used to sweetened drinks but normally drinking diet, it's easy to choose a non-diet one rather than water/tea if there's no diet one to their taste available.

The biggest "catch" (or actual problem, for some of us) with stevia is the funny aftertaste. Although pretty much all non-nutritive sweeteners have some level of aftertaste -- mixing more than one seems to be the least-bad option in diet sodas -- but stevia's is to my taste much stronger. Then again, I really hate the whole licorice/anise/fennel family of flavors, so I'm sure that plays a part.

I'm sure it seems like a good place to start for some people. It may not for some others.

I have got the same problem love the water taste but im not sure whether is safe in large amounts.