Traffic light labelling - whether red lights will stop us eating bad foods. Sheila Dillon investigates whether this year's change in food labelling will encourage us to improve our diet.Sue Davies from Which? explains the change to food labelling. This year a consistent system will be adopted across supermarkets. The labels will show a combination of guideline daily amounts, colour coding and "high, medium or low" wording will be used to show how much fat, salt and sugar and how many calories are in each product.Dr Mike Rayner has worked on a system like this since the 1980s. He celebrates this as a landmark year in public health, but thinks that the traffic light system still is not perfect.And New York Times columnist Mark Bittman describes his dream food label, which would also include details about animal welfare and how processed the food was.Presented by Sheila Dillon and produced by Emma Weatherill.