WASHINGTON - For a health-food nut, President Obama sure likes his burgers.

Obama made a surprise lunchtime stop yesterday at Five Guys, a fast-food restaurant in Washington.

The president ordered a cheeseburger with lettuce, tomato, jalapeno peppers and mustard, as well as several cheeseburgers to go - one of them for Brian Williams, news anchor for NBC. The network was filming a day-in-the-life program at the White House.

White House press secretary Robert Gibbs said the president wasn't showing off for the cameras.

"I can assure you it was done simply for the benefit of the appetite of the commander in chief," Gibbs said.

The president snacked on peanuts, and chatted with surprised customers while he waited for his order.

There are "more problems than we thought," Obama told a man who asked him about his first months in office.

Gibbs joked that while the cheeseburgers at the White House are pretty good, the president likes to "get out of the gate a little bit."

First lady Michelle Obama has also proven herself to be a burger fan. She recently said she snuck out to a Five Guys restaurant without anyone noticing. *