Last Tuesday, Prudential analyst Larry Miller mentioned that companies like McDonald's (NYSE:MCD), Wendy's (NYSE:WEN), and Outback Steakhouse (NYSE:OSI) "could get skewered by rising beef costs." Miller's pun may have been a nice play on words, but investors who drove the companies' prices down by as much as 3% on the day -- even after a late recovery -- were just unwise.

That's because, by Thursday, all three companies had released overwhelmingly positive quarterly reports, none of which were particular surprises to those investors not swayed by the day-to-day chatter of Wall Street analysts.

As Fool LouAnn Lofton noted on Wednesday following McDonald's report, investors had been expecting good news from the fast-food giant since earlier in the month, when the company announced substantial growth in same-store sales over the last two quarters. That good news came, in the form of 11% growth in overall revenues and substantial increases in U.S. sales and operating income.

Similarly, Outback Steakhouse's earnings report showed staggering revenue growth, confirming Fool Rick Munarriz's opinion from way back in June that some steak -- er, stake -- in Outback would make a great Father's Day gift.

Wendy's, too, had a good week, showing better than 11% growth in revenues over last year, and greater than 10% growth in profit over the same time period. Although Wendy's did note that beef prices would be 8% higher than anticipated for the coming quarter, the company maintained its long-term goal of 12%-15% earnings growth. With earnings this quarter beating analysts' expectations by four cents (at 58 cents per share), it seems they're off to a good start.

Though beef costs are indeed rising, it is important to note (as Miller didn't) that these companies are all deemphasizing beef in their menus and marketing. McDonald's has unveiled (and promoted heavily) new Chicken McNuggets, Happy Meals for the health-conscious, and meal-sized salads. Wendy's, thumbing its nose at the "Old Fashioned Hamburgers" part of its moniker, is pushing its Homestyle Chicken Strips above all else. Even beef-centric Outback Steakhouse has plans for a P.F. Chang-style Chinese-casual restaurant.

Share prices for all three companies were up as last week closed. But whether prices are up or down, the market's daily fevers and fluctuations aren't worth fretting over. Those who sold out on the warnings of one analyst will miss out on the real meat of these companies: their sound management and continuing growth.

Devan Goldstein can be reached at devan@mac.com. He has never eaten a hamburger, nor does he own any of the companies mentioned in this article.