Whilst life expectancy is declining in the UK and America and other high-income countries, some tech billionaires have become obsessed with life longevity - but which factors really impact how long we live and when we die? 

Public health expert Devi Sridhar speaks to Krishnan Guru-Murthy on Ways to Change the World about the launch of her new book 'How not to die (Too Soon).

She explains how changing our public health policy could improve life expectancy, what the UK can learn from other countries when it comes to health, and what her own cancer diagnosis taught her about the state of the NHS’ waiting list times.