NEW YORK (TheStreet) -- The term "untouchable" has several meanings on the stock market. There's the reference that describes companies that you should never touch, regardless of how cheap the stock looks.

Then there are stocks that somehow never get cheap. It is as if they have become immune to criticism, shielded from the market's punishment regardless of how underwhelming their performances might have been.

This would seem to describe Coca-Cola ( KO), whose business, by its own standards, no longer seems as bubbly. I'm not going to try to make excuses for Coca-Cola. But there are a lot of things at play here. Contrary to popular opinion, I don't believe the company's recent decline in revenue is the result of losing share to rival Pepsico ( PEP).

The fact is, volume in the soft drink industry has been down across the board -- neither Pepsi or Nestle ( NSRGY) have been no exception. But the extent of Coca-Cola's volume struggles, which produced just 1% year-over-year growth, was a disappointment. This was 2% lower than Street expectations, which had already been revised lower more than a month prior to the report.

However, as has been the case for quite some time, Coca-Cola's "flat" performance really didn't seem to matter. The stock, in fact, which has been up by as much as 15% for the year to date, went up by more than 2% in the days following the earnings report.

The reason is simple. Unlike most companies, Coca-Cola has shown an uncanny ability to "struggle" and still grow market share at the same time.

This is a quality that is shared by other iconic brands like McDonald's ( MCD) and Nike ( NKE). Coca-Cola is safe -- hence its "untouchable" status. Essentially, investors have had no problems paying any sort of premium that Coca-Cola commands, which is why the company never trades at any price below fair value.

I won't argue that this level of trust is has been well earned. But I do wonder how long this can continue, especially with Coca-Cola now posting revenue declines in North America and Europe, which were both down 1% and 4%, respectively. The good news here is that the company has been able to offset its North American struggles with better volume growth in emerging markets like Africa and Latin America.

Nevertheless, for the stock to work in the long term, Coco-Cola has to overcome the elephant in the room. It's no secret that obesity, which plagues close to 40% of Americans, have become a global concern. Some countries are more responsive than others. Many states have begun to prioritize ways to address (among other things) beverage consumption, which according to many experts is a key contributor to weight gain.

"Liquid candy," as soda is often called, is no longer just a "fun" moniker. In some cases, it's become a life or death situation. Here, too, Coca-Cola is not alone in overcoming this challenge. I don't believe it's coincidence that for both Pepsi and Dr. Pepper Snapple ( DPS), sales volumes were also down.

The question, though, is how much investors are willing to risk that Coca-Cola can still thrive in a more health-conscious market.

In that regard, I don't believe that Coca-Cola's management has received enough credit for the fine job it has done in educating consumers about the health effects of its products. The company done this, while at the same time promoting regular exercise. It is taking the obesity issue head-on. But the company hasn't stopped innovating.

While looking for ways to offset prolonged weakness in the soft-drink business, the company feels a new product called Coca-Cola Life just might be the answer. It's a new drink that uses a blend of sugar and Stevia, a plant-based sweetener that has no calories. It remains to be seen how well this is embraced by consumers and to what extent it alters the company's nutritional profile.

The company's stock price, which is still rich by many standards, makes it clear investors believe that for Coca-Cola it will be business as usual, which means plenty of sales and even bigger profits.

From my vantage point, I don't believe volumes can continue to decline and not expect that the stock price will suffer. Granted, it hasn't happened yet and the stock has never really been cheap. But, as they say, there's a first time for everything.

At the time of publication, the author held no position in any of the stocks mentioned.

This article was written by an independent contributor, separate from TheStreet's regular news coverage.

Richard Saintvilus is a co-founder of where he serves as CEO and editor-in-chief. After 20 years in the IT industry, including 5 years as a high school computer teacher, Saintvilus decided his second act would be as a stock analyst - bringing logic from an investor's point of view. His goal is to remove the complicated aspect of investing and present it to readers in a way that makes sense.

His background in engineering has provided him with strong analytical skills. That, along with 15 years of trading and investing, has given him the tools needed to assess equities and appraise value. Richard is a Warren Buffett disciple who bases investment decisions on the quality of a company's management, growth aspects, return on equity, and price-to-earnings ratio.

His work has been featured on CNBC, Yahoo! Finance, MSN Money, Forbes, Motley Fool and numerous other outlets.