While some restaurant stocks posted delicious results last week, Panera Bread's (Nasdaq: PNRA) and Buffalo Wild Wings' (Nasdaq: BWLD) latest earnings may now prompt investors to reach for the antacid.

Half baked?
To its credit, Panera did deliver rising amounts of bread. First-quarter net income increased 48%, to $25.8 million, or $0.82 per share. Total revenue increased 14%, to $364.2 million. Same-store sales for company-owned locations also jumped a staggering 10%. That increase included transaction growth of 3.5% and average check growth of 6.5%. Panera raised prices by 2%.

If Panera's share price today implies that investors have lost their stomach for the stock, that's probably because the company warned that second-quarter earnings will miss analysts' expectations. Panera expects $0.81-$0.83 per share, while analysts had forecast earnings of $0.84 per share.

Wild disappointment
Alas, investors' dismay with Panera today is just a walk in the park compared with the woes of Buffalo Wild Wings. Last time I checked, its shares were down nearly 20%.

Buffalo Wild Wings' first-quarter net income increased 24.5%, to $10.6 million, or $0.58 per share. Total revenue didn't look too shabby, either, up 15.7%. However -- and here's the bummer -- its same-store sales were flat.

Apparently, April is the cruelest month, at least for Buffalo Wild Wings. In the company's press release, CEO Sally Smith explained that April same-store sales are down 3.7% thus far at company-owned locations, and 2.4% at franchised restaurants. Investors probably feel a bit chilled by Smith's declaration that Buffalo Wild Wings' 20% earnings growth goal "may be achievable," provided it can get same-store sales growth going again and secure moderate wing prices.

No thanks, I'm stuffed
Last week, results from McDonald's (NYSE: MCD), Starbucks (Nasdaq: SBUX), and Chipotle (NYSE: CMG) all gave investors a hearty appetite. Too bad Panera and Buffalo Wild Wings couldn't keep up.

The negativity surrounding Panera seems like an overreaction; its guidance may fall a tiny bit short of analysts' expectations, but it still represents impressive 25%-28% earnings growth. Bear in mind, though, that premium-priced stocks like Panera and Buffalo Wild Wings tend to get slammed by the slightest whiff of negativity. Even with today's haircut, Panera still trades at 27 times trailing earnings -- not exactly traditional value territory.

On the other hand, caution may be in order on Buffalo Wild Wings. Its shares got slammed last quarter, too, and its slowdown in comps seems fairly ominous. Last year this time, its aggressive expansion plan looked like a dubious move amid recession; now, that plan appears to be backfiring. Today's stock slide has discounted Buffalo Wild Wings to a price-to-earnings ratio of 23.

In contrast, a more reasonably priced stock like McDonald's has been an excellent performer, but only trades at 17 times earnings.

Is it time to buy Panera or Buffalo Wild Wings? Or would you rather load up on a less expensive stock like McDonald's? Sound off in the comment box below.

Buffalo Wild Wings and Chipotle are Motley Fool Hidden Gems picks. Chipotle is a Motley Fool Rule Breakers recommendation. Starbucks is a Motley Fool Stock Advisor choice. The Fool owns shares of Chipotle. Try any of our Foolish newsletters free for 30 days.

Alyce Lomax owns shares of Starbucks. The Fool has a disclosure policy.