The good times continue to roll at McDonald's (NYSE:MCD), and the sales increases could last longer than expected.

The burger slinger announced today that September comparable restaurant sales jumped 7.3%, driven by a 10.6% jump in U.S. sales and a rise of 7.3% in the Asia/Pacific, Middle East, and Africa areas. Sales in Europe were the one soft spot, as they declined 0.6%.

Still, for all of the third quarter, even European sales improved (albeit slightly), putting growth at a nice 5.8% clip. These gains on the top line translated into equally satisfying earnings results, with McDonald's posting preliminary results of $0.61 per share, up 42% year over year. Even after subtracting out a $0.07 per-share tax benefit in the quarter, Mickey D's profits remain something to behold.

So, how long can these happy days go on? Motley Fool contributor Cass Bielski recently noted that McDonald's performance is likely to level off after a strong recovery. Still, investors should probably not expect a major slump in sales.

After a long period in which burgers got a bad rap, America's signature food is enjoying a renaissance. The low-carb diet has helped this trend along, as even those folks who are not dieting are discovering that good, old-fashioned red meat may not be so terrible after all. CKE Restaurants (NYSE:CKE), Steak n' Shake (NYSE:SNS), and scores of others are seeing the benefits of this change in attitude.

McDonald's results may not be as supercharged as they have been in the past. But eating habits have changed, and this probably means that the fast food giant will have an easier time of growing sales over the long haul.

Fool contributor Brian Gorman is a freelance writer living in Chicago, Ill. He does not own shares of any companies mentioned here.