Obama's cabin fever?

Maybe President Obama's getting tired of the White House food.

For the second time in two days, he's bolted from 1600 Pennsylvania Avenue to grab some nourishment, this time taking Education Secretary Arne Duncan to a local burger joint.

The two hit up FireFlies Restaurant in suburban Alexandria, Va., Tuesday afternoon and the president stopped to shake a few hands along the way. There was a moratorium on selfies, with the president explaining, "I've got to get back to work pretty quick."

The Obama selfie has exploded in the past year, with British Prime Minister David Cameron, Danish Prime Minister Helle Thorning-Schmidt, Malaysian Prime Minister Najib Razak and Vice President Joe Biden all snapping photos of themselves with the president. It's an activity now viewed with caution by the White House since another selfie with the president taken by Red Sox player David Ortiz turned out to be a promotional stunt for Samsung.

Mr. Obama picked FireFlies because the owner, Marylisa Lichens, wrote to the president in March inviting him to try what she deemed the best burger around. She lives two hours away and missed his visit, but when Mr. Obama called her from the restaurant he deemed her burgers "tasty" and said, "I was very happy with it."

White House spokesman Josh Earnest said the trip wasn't a ploy for attention, but rather the chance to seek a nice meal on a beautiful day.

And it hasn't been the first time in recent weeks the president has headed out in the D.C. area unannounced.

On Monday, Mr. Obama slipped out of the White House - "the bear is loose again," he told a staffer - and strolled over to a Starbucks near the White House with Chief of Staff Denis McDonough. Last month, he and Vice President Joe Biden dined at a D.C burger shop with workers from a local reconstruction project. Also in May, he decided to walk to the Interior Department for a meeting rather than drive, and also stopped at a D.C. little league team practice en route to a fundraiser to toss a ball around and take some pictures.

"I don't get a chance to take walks very often," Mr. Obama said last month. "Secret Service gets a little stressed. But every once in a while I'm able to sneak off. I'm sort of like the circus bear that kind of breaks the chain."

While Secret Service might get nervous about his impromptu trips, CBS News Senior White House Correspondent Bill Plante points out Mr. Obama is hardly the first president to get a case of cabin fever at the White House.