Journalist Nina Teicholz has written for the New Yorker, the Economist, and the New York Times.

She says the F-word - Fat - is not the enemy, and that our long-held beliefs about fat don't add up.

Nina Teicholz makes the case in her new book, 'The Big Fat Surprise - Why Butter, Meat and Cheese Belong in a Healthy Diet'.

She talks to Simon Mercep about fat.