Secrets of Your Supermarket Food

The pros and cons of going green. Stefan Gates goes on a crash vegan diet for a month, monitoring the effect on his body. Sian Williams visits a food company that specialises in meat replacements, such as jackfruit burgers and vegan pork scratchings. There's also a comparison of vegetarian ready meals and their meat alternatives, and a look at whether it's better to buy fruit and vegetable locally or from imported from abroad.