Source: Panera Bread.

The rise of the fast-casual dining space has surprised many investors, as an increasingly health-conscious American public looks for a middle ground between the perceived problems of traditional fast food and the added expense and wait times involved with full-service restaurants. Panera Bread (NASDAQ:PNRA.DL) has sought to provide that perfect balance with high-quality food offerings served quickly and efficiently. Yet even with overall trends on its side, Panera came into its third-quarter earnings release with investors wondering about just how fast the company can keep growing, and mixed results didn't allay any of those fears. Let's take a closer look at how Panera Bread did last quarter.

Why Panera's results left investors hungry for more
Panera's headline numbers once again failed to give investors the strong growth they've been missing lately. Net income of $39.2 million was down more than 8% from year-ago levels, and even after taking out one-time gains from tax adjustments both this year and last year, diluted earnings per share rose only 2%. Moreover, the final earnings number fell short of what investors had expected, after adjusting for the one-time tax gain.

Source: Panera Bread.

On the revenue front, total sales jumped more than 8%. But much of that growth came from Panera's expansion efforts, as comparable-store sales at its company-owned locations rose by only 2.1%, with comparable traffic figures showing gains of 1.4% and a slight 0.7% rise in average order size. Growth at its franchise-operated cafes was even more sluggish, with comps coming in at 0.7% and bringing Panera's systemwide comparable sales figures to just 1.4%. Moreover, even these figures made an adjustment to reflect the extra week in last year's third quarter.

Panera tried to put a positive spin on its growth figures, releasing comps of 3.3% for the first 27 days of the fourth quarter. Moreover, the company continued to build out new locations, opening 13 new company-owned stores and 15 new franchise locations during the quarter. As of Sept. 30, Panera had 1,845 stores in its network, split roughly equally between company-owned and franchise-operated restaurants.

Can Panera ever start rising again?
Unfortunately, Panera has lost some of its upward momentum, and its own management admits that growth won't be as strong for the full year as it had originally hoped. After coming into the quarter with an expected full-year earnings range of $6.65 to $6.80 per share, Panera said in its third-quarter release that actual results would be $6.60 to $6.70, which is generally below the expectations that most investors had for the company. Weaker comp growth of 1% to 1.5% for its company-owned restaurant sales also reflects the concerns that investors have about Panera's chances of getting back on track.

CEO Ron Shaich. Source: Panera Bread.

CEO Ron Shaich still looked for the bright side for Panera, noting that the 1.4% rise in the number of transactions was the highest in more than two years. Shaich also looked forward to the rollout of the Panera 2.0 mobile pre-ordering system, as well as other initiatives aimed at improving Panera's technology capabilities, delivery hubs, and operational integrity.

Still, investors need to be prepared to wait for a while for Panera's turnaround to take shape. As Shaich warned, "We expect the rollout of these enhancements will have an adverse impact on our 2015 results." Nevertheless, he hopes that "they offer the potential to elevate Panera's competitive position and broaden our growth opportunities, which will, in turn, lead to expanded medium- and long-term earnings growth."

Shareholders didn't initially choose to see things as positively as Shaich, with the stock falling about 3% in the first hour of after-hours trading following the announcement. Given that Panera still sports a fairly high earnings multiple, the restaurant chain will need to get its growth engine back in order within a short timeframe. Otherwise, the growth-oriented investors who helped drive Panera's stock higher could reverse course and look for better prospects ahead -- and that could spell tough times for Panera shares in the future. Even long-term investors who aren't worried about a knee-jerk response to an earnings announcement nevertheless need to keep an eye on how well Panera executes on its strategic plan going forward. Any Panera turnaround depends on the company's ability to get back some of its former glory to bring diners back in the door.

Dan Caplinger has no position in any stocks mentioned. The Motley Fool recommends and owns shares of Panera Bread. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.