Any investors questioning how long McDonald's (NYSE:MCD) could keep us all lovin' it found their answer today. The company gave an upbeat preview of second-quarter earnings, stating that it will exceed analysts' expectations, driving its stock price up 5%.

Early worries about April's loss of the company's CEO Jim Cantalupo, widely regarded as the engineer of the company's high-profile turnaround, seem to have some reason to subside.

McDonald's said second-quarter earnings will come in at $0.47 per share, a 27% increase over the same period last year and $0.03 better than analysts' expectations. Worldwide same-store sales were up 5.6% in June, following a similarly upbeat May. Second-quarter comparable sales increased 7.8% -- what the company described as the highest second-quarter sales increase since way back in 1987.

As an investing space, fast food has been a hot topic over the last year. McDonald's results look hotter still when you consider the fact that it's claimed sizzling same-store sales gains in June while burger rival Wendy's (NASDAQ:WEN) recently lagged, blaming cold weather and, one might guess, a certain degree of consumer malaise.

When it comes to burgers, McDonald's also faces competition from private companies such as Burger King and Subway, as well as Yum! Brands (NYSE:YUM), which runs the Pizza Hut and Taco Bell chains and got some Foolish treatment today.

What helped boost McDonalds' second-quarter outlook? Exactly some of the recent initiatives we've watched and wondered about. The company's new emphasis on healthy fare and technologically appealing promotions are among the reasons cited for the company's turnaround. Mickey D's cited the launch of its meal-sized salads in Europe, as well as its promotion with Sony's (NYSE:SNE) Connect service, featuring downloaded tunes to go with Big Macs. (Watch as rivals try to copy that successful promotional offer.)

There's plenty on the plate for McDonald's right now. You might wonder how a recent fat lawsuit might impact the fast-food giant, or contemplate whether push-button kiosks will improve its fortunes. Regardless of the good news, investors may very well want to brace themselves for some degree of sales slowdown in the second half of the year. After the successes in the last year, it's hard to imagine it's not inevitable.

How much gold is left in the Golden Arches? Get together with other Fools on the McDonald's discussion board.

Alyce Lomax does not own shares of any of the companies mentioned.