Food waste is a global problem. According to the UN, one third of the food that we produce is being thrown away. Two London-based technology start-ups aim to change that. Smartphone app Olio encourages people to share food they no longer want with their neighbours. Meanwhile, Winnow has developed a smart bin which allows chefs to record how much food they’re throwing away, so they can make their kitchens more efficient. Presenter: Dougal Shaw Reporter: Ammar Ebrahim Photo Caption: Food waste mountain Photo Credit: BBC