Some of the best restaurant stocks these days are also arguably the priciest. Panera (Nasdaq: PNRA) has historically sported a high valuation, and while today's quarterly results were decent, I'm still leery of the stock.

Panera's second-quarter net income increased an admirable 28%, to $20 million, or $0.65 per share. Even with $0.04 per share in charges included, that's an impressive result.

However, Panera's total revenue increased a mere 3%, to $330.8 million. Systemwide comps were fairly anemic, decreasing 0.4%. Panera blamed the shift of Easter; without that negative effect, the company said comps would have been essentially flat. Thus, to increase its profit, Panera had to rein in costs.

Panera reported that its customers' average check increased by 3% -- which sounds nice, until you learn that the gain was attributed to menu price increases. Price increases have been a common tactic to boost revenue across the consumer space, from restaurants like Panera to giants such as Philip Morris International (NYSE: PM).

For Panera, hiking prices implies that the company needs to work harder at getting customers in the door. Same goes for Starbucks (Nasdaq: SBUX), one of many companies that has reported impressive quarterly profits this earnings season, but which remains challenged by dwindling sales.

On the other, more successful hand, Buffalo Wild Wings (Nasdaq: BWLD) and Chipotle (NYSE: CMG) (NYSE: CMG-B) both reported more impressive revenue and same-store sales increases. When so many consumers are flocking to lower-priced eateries such as McDonald's (NYSE: MCD), these gains are great feats.

I nominated Panera as the worst stock for 2009 in January, and my skepticism hasn't waned since. For starters, Panera's price-to-earnings ratio still looks high, at more than 21 times trailing earnings; McDonald's, which has been operating very successfully, trades at only 15 times earnings. Sure, Panera looks cheaper than Buffalo Wild Wings (26 times earnings) and Chipotle (32 times earnings), but their sales growth and comps are far brisker than Panera can manage.

Panera's now guiding for EPS growth of 17%-21% this year, an increase on its prior prediction. However, it still needs to drum up more business. Given consumers' new frugality, making the high end of those targets could be a big challenge during the remainder of the year, especially if sales slack off.

In light of that increasingly stale outlook, a low-carb portfolio might be best. I still think investors should pass on the Panera Bread.