Potatoes are having a moment.

Once dismissed as dull, stodgy or even unhealthy, they’re now back, appearing on restaurant menus, in food magazines and across social media feeds.

But the story of the potato goes back much further.

In this episode, Ruth Alexander traces the journey of one of the world’s most familiar foods. From its origins millions of years ago to its place in today’s global food system.

AJ Shehata, senior sous chef at Fallow restaurant in London explains why the potato forces chefs to get creative.

At the Natural History Museum, botanist Sandy Knapp explains how the potato may have been born from a chance encounter between two wild plants in the Andes, an event that made it possible for potatoes to grow underground and spread across new environments.

We explore how the potato became a global food. Potatoes USA president Blair Richardson explains how demand continues to grow worldwide, and how the industry is working to reshape the potato’s image.

We ask whether the potato’s reputation is deserved. Nutrition scientist Candida Rebello shares research suggesting potatoes may be far more beneficial, and more misunderstood, than many people think.

And at the International Potato Center in Peru, scientist Julian Soto works with farmers to conserve thousands of native potato varieties. In the Andes, potatoes are not just a crop, they are part of culture, identity and family life.

From ancient origins to modern revival, this is the story of how the potato conquered the world, fell out of favour, and is now being rediscovered, just as new challenges begin to emerge.

If you’d like to get in touch with the programme, please email: [email protected]

Producer: Izzy Greenfield Sound engineer: Hal Haines Picture: Getty

It's exam season in many parts of the world and with her own daughter studying hard, Rumella Dasgupta began wondering how much food matters during this difficult and stressful time.

Is there such a thing as a brain food and are there any foods in particular that we should be aiming to eat while studying hard?

Rumella talks to students and experts about the role diet plays and what happens to our eating habits when we're under intense pressure. Plus are energy drinks ever a good idea before an exam, and what should we do when the junk food cravings hit? Featuring Professor Julia Rucklidge, director of Te Puna Toiora, the Mental Health and Nutrition Research Lab at the University of Canterbury in New Zealand and Lucy Upton, a UK based paediatric dietitian who supports her teenage clients to eat better during this stressful phase of their lives.

Plus teenagers and university students in the US and India discuss what they like to eat and drink when studying.

With special thanks to Zumix in Boston.

Producer: Lexy O'Connor

Sound engineer: Andrew Mills Image: a dark-haired teenage girl is sprawled on her bed. She has a biscuit in her mouth and is writing in an exercise book. Credit: Getty images.

If you would like to get in touch with the show, please email: [email protected]

Food Chain presenter Ruth Alexander was confident that she was eating a healthy diet, in particular, a diet that included enough fibre. But it turns out, like many of us, her fibre intake has been falling short of the recommended amount.

In fact all over the world most of us are failing to eat enough, despite the growing trend for so called "fibremaxxing" where people try to maximise their daily intake. So how can we boost our fibre intake? And does it really have to involve chia seeds?

Ruth picks the brains of fibre expert Professor Joanne Slavin from the University of Minnesota and Fathima Abdoola, known as The Cultural Dietitian, based in Brisbane Australia. And psychologist Phillippa Lally from the University of Surrey in the UK, explains how we can make our well intentioned new habits stick.

Producer: Lexy O’Connor

Sound engineer: Andrew Mills

(Image: A close up of a steaming bowl of Persian barley soup, in a blue bowl, with a woman’s hands holding it. Credit: Getty Images)

If you would like to get in touch with the show, please email: [email protected]