Victoria Beckham has devised a strict diet and exercise regime for the Spice Girls to help get them in shape for their upcoming world tour.Victoria is keen for her bandmates - Emma Bunton, Mel C, Geri Halliwell and Mel B - to look their very best when they take to the stage in December, and has allegedly told the girls they should follow her healthy eating plan to shift any excess pounds. A source said: "Victoria has told the girls her secret to getting in shape is 200 sit-ups a day and a diet of edamame soya beans, strawberries and lettuce. She is determined to make sure the reunion goes well because her image in America is important to her. She wants the girls to all look their very best, and says her diet is a guaranteed way of losing the pounds."The girl group announced they were reuniting last week for an 11-date tour and to release a greatest hits album.The band will kick off the series of shows in Los Angeles, followed by concerts in Las Vegas, New York City, London, Cologne, Madrid, Beijing, Hong Kong, Sydney, Cape Town and Buenos Aires.