LONDON, ENGLAND - DECEMBER 21:  Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge attend a 'healthy living cookery session' during a visit to Centrepoint's Camberwell Foyer on December 21, 2011 in London, England. The national charity, Centrepoint, provides housing and support to improve the lives of homeless young people aged 16-25.  (Photo by Ben Stansall-WPA Pool/Getty Images)