In a save-the-date email guests have been advised to dine before coming to the 'Snacks & Sips & Dancing & Dessert' party on January 18.
Michelle's actual birthday is on January 17 and she is currently enjoying President Barack Obama's gift - an extended vacation in Hawaii. The First Lady will celebrate the milestone birthday at the White House.
Michelle does not want to mess around with food at her 50th birthday party and therefore guests have been instructed to eat before they arrive at the White House, the New York Daily News reported.
The coterie of invitees received the email for the event, with strict guidelines to wear comfortable shoes, practice their dance moves and arrive with a full stomach ? a directive that has left some etiquette experts scratching their heads.
Michelle hinted about her birthday plans during last month's visit to a children's hospital, when a girl asked her about her big day. "It might involve some dancing," she told the girl. "A little Dougie."
The Dougie, a hip-hop dance, was one of the moves The First Lady performed on "Late Night with Jimmy Fallon".
"I don't think it's rude, but I do think it's a little... different," Lizzie Post, great-great-granddaughter of Emily Post, told the Washington Post.
"I've never seen it said straight out. That is definitely new," said Washington area party planner Andre Wells.
The self-dubbed mom-in-chief turns 50 on January 17 and will hold her food-light celebration the next day, likely in the White House East Room.
There is no word on who is on the guest list, though many suspect hip-hop royalty Jay-Z and wife Beyonce will be among the revellers.
She got an early birthday present from the President - an extended Hawaiian vacation after the family holiday stay on the island.
The President and daughters Malia, 15, and Sasha, 12, returned to the arctic temperatures in Washington on Sunday, leaving the birthday girl behind.
The First Lady is relaxing at the Oprah Winfrey estate in Maui for a "girl getaway" with CBS morning host Gayle King, President Obama's adviser Valerie Jarrett and Sharon Malone, wife of Attorney General Eric Holder, The Daily Caller reported.
White House Press Secretary Jay Carney told reporters on Monday "the first family will appropriately fund personal expenses," but said a government aircraft will be used for her travel back to Washington.