Season 6 - Episode Guide

Michael Mosley investigates whether diet or exercise is a more effective way to keep calories in check, and Saleyha Ahsan runs an experiment to find out whether probiotic products really can improve health. Chris van Tulleken discovers whether red wine lives up to its healthy reputation, Zoe Williams looks at how sleep duration affects how much people eat, and Gabriel Weston witnesses the first operation of its kind in the UK - fitting a sternum implant made using 3D printing.

Dr Zoe Williams investigates whether people can boost their metabolism, Michael asks whether people should be worried about air pollution, and Dr Saleyha Ahsan meets survivors of eating disorders to try to identify the signs and symptoms. Gabriel Weston visits the Netherlands to find out about a new treatment for eczema, and Dr Chris van Tulleken reveals what kind of weights people should be lifting at the gym.

Michael conducts an ambitious study on the health benefits of omega-3 fish oils, while Dr Chris van Tulleken puts omega-3 supplements to the test. Dr Zoe Williams goes on a high fat diet and discovers why eating a lot of fat affects men and women differently. Gabriel Weston seeks out an innovative new brain treatment for PTSD, and Dr Saleyha Ahsan reveals how to spot the symptoms of a little-known condition that can cause sudden and irreversible sight loss.

The team conducted a survey of 2,000 people to find out what mental health questions the public most wanted answered. The top question was how to beat stress: Michael Mosley runs a big experiment to test mindfulness, yoga and gardening to find out which is the best stress-buster. New presenter, psychiatrist Dr Alain Gregoire, tests how lack of sleep affects our mental health and uncovers some unexpected symptoms. Dr Zoe Williams finds out why laughing can be as good as exercise for improving mood. Surgeon Gabriel Weston investigates the radical new treatment that could cure schizophrenia in many patients and holds new hope for more common mental illnesses like depression. And geneticist Dr Giles Yeo finds out if you can eat your way to happiness.