Word got out during an interview that Michelle Obama taped ahead of time and was broadcast Tuesday on Smith's program on SiriusXM radio.
Smith said her menu will be soulful and healthy. Mrs. Obama described White House staff as anxious to get their lips on Smith's food.
Smith's restaurant at Washington's Union Station serves Cajun, Creole and Southern food. She also has two restaurants in New York.
The White House mess was established in 1951. Cabinet secretaries can make reservations to eat in, while West and East wing staff are served by a takeout window.
Smith's stint is part of Black History Month observances by the White House.