The 'couch potato' is an idler, the 'cabbage-head' a dunce, Swede-bashers are stupid and you may as well give up life if you become a vegetable. A vegetable existence may imply dull monotony, but the human vegetable has sparked protests, threatened to topple a British government and almost triggered a revolution. From the Scottish Presbyterian campaign against the 'sinful potato' to the class act that turned the carrot into a propaganda tool, from...