Episode 4

Michael Mosley runs an experiment to find out which foods are best for providing a crucial but neglected nutrient: iodine. Geneticist Dr Giles Yeo discovers why stress can make you put on weight. GP Dr Zoe Williams tackles the question: how safe are x-rays? Michael questions two experts on how the NHS spends our money. And psychiatrist Dr Alain Gregoire reveals how mental health first aid aims to reduce the rates of suicide and mental illness.