Is BMI working? Cop31 latest, the science of great conversation

Madeleine Finlay and co-host Ian Sample discuss the three science stories you need to know about this week, including an alternative to BMI for diagnosing obesity which could ‘prevent misdiagnosis for millions’. Also on the agenda: an update from this year’s Cop climate conference in Turkey, and a study that claims to have found the key to better conversations with the help of a concept from physics. Help support our independent journalism at theguardian.com/sciencepod