Michelle Obama is to be the first presidential wife to appear on a reality TV series. The First Lady will make a guest appearance on 'Iron Chef America' which features British cook Nigella Lawson as a judge. The episode of the popular series, which pits well-known chefs against each others, has been filmed at the White House and will be aired in the New Year. Many of the ingredients for the meals prepared in the show were chosen from the recently planted White House vegetable garden.