On this week's Book Club podcast my guests are the former government food tsar Henry Dimbleby and his wife and co-author Jemima Lewis, to talk about their new book Ravenous: How To Get Ourselves and Our Planet Into Shape. They tell me about the perils and pleasures of working with your spouse, why exercise doesn't make you lose weight, what we don't understand about nutrition, when the state needs to take a hand in consumer choice – and why sending Liz Truss a picture of a sheep's mutilated backside might not have been the best idea.