The doctor puts five volunteers on a low-calorie diet to help get their health back on track after the UK's Covid-19 lockdown. In the third and final week of the diet challenge, Michael explores the connection between comfort eating, and the different ways our brains respond when faced with a bar of chocolate as opposed to a pile of fruit and vegetables. He also has the unique experience of having a camera stuck up his nose to learn about the connection between weight, snoring and the life-limiting condition of sleep apnoea