Ian Sample hears from Guy Leschziner, a consultant neurologist and sleep physician at Guy’s and St Thomas’ hospital in London, whose new book, Seven Deadly Sins: The Biology of Being Human, looks at the neurological basis of behaviours often dismissed as evidence of bad character or lack of willpower

In this episode from July, Ian Sample talks to the philosopher Julian Baggini, the University of Oxford academic dietician Dr Nicola Guess, and Zoe’s chief scientist the King’s College London nutrition expert Prof Sarah Berry to find out what we know about blood glucose levels and our health, and whether the science is nailed down on personalised nutrition