In what has been billed as a ‘world first', fast food grown in a laboratory was served up in London recently. Hardtalk speaks to professor Mark Post who says his `in vitro burger' could be the answer to our unsustainable appetite for meat and help ease the burden on the environment. There's clearly a need for more meat - the World Health Organisation estimates annual global production will have to double by 2050. So will meat grown from stem cells in a science lab ever make it to our dinner plates?Picture: Mark Post holds an 'in vitro' burger, Credit: Reuters/David Parry