Christmas at the White House isn't for sissies.

Take quantities that might work in a private home _ guests, cookies, parties, cards, whatever _ and add some extra zeros to get a feel for a White House-sized holiday season.

As in 50,000 guests, 28 parties and open houses, a couple hundred thousand holiday cards and untold quantities of cookies, cakes, brownies, truffles and the like to feed the Obamas' holiday throng.

"They eat like crazy," says former White House executive chef Walter Scheib, who cooked for the masses under presidents Bill Clinton and George W. Bush. "Christmas at the White House is the single most mentally and physically challenging thing that you can do."

Scheib said the staff used to joke during the holidays about "White House flextime" _ when "you can work any 100 hours you want this week."

As far back as October, pastry chef Bill Yosses' team was plotting strategy and going over drawings for this year's gingerbread house _ a 390-pound behemoth whose construction required the use of a band saw. Before Halloween, Yosses already was joking about doing "mental push-ups" to prepare for the coming holiday season.

Yosses' shop stockpiles mounds of cookie dough in the freezer to keep up with day-to-day demand for holiday sweets.

His rule of thumb for receptions: four bite-size dessert items per guest. (Some of which are discreetly slipped into purses and go home as souvenirs.)

This year's menu for the White House dessert buffet table: lemon layer cake, brownies, assorted cookies, pecan pralines, pumpkin pie, chocolate truffles, and more.

Roland Mesnier, one of Yosses' predecessors, says he always tried to sock away enough dough for 120,000 cookies and sweets by Dec. 1.

"If I did not have that, I would be in trouble," Mesnier said.

Michelle and Barack Obama, meanwhile, might want to stockpile hand sanitizer: There's a whole lot of handshaking going on at all those parties and receptions _ although White House aides say the Obamas are doing away with formal receiving lines and posed photos with each guest at some events to accommodate more people.

The jockeying for a White House invite is intense enough to sorely test any host's holiday spirit. Speculation over who'll get to attend the president's Hanukkah party, for example, has been swirling in Jewish publications since mid-November, along with grousing that the party's size is down from last year's 800 guests. About 500 will attend this year, about the same number as in earlier years in the Bush administration, according to White House aides.