Horizon investigates the idea that the best way to lose weight successfully is a personalised approach, diets tailored to our individual biology and psychology. In a groundbreaking experiment, Dr Chris van Tulleken and Tanya Byron join a team of experts to put 75 overweight volunteers on diets designed to tackle the specific reasons why they eat too much. The volunteers are put through a series of tests at a residential clinic to understand how their genes, hormones and psychology influence their eating behaviour. They are then put on the diets the experts believe are best suited to them. Can science succeed where other diets have failed?

The world is affected by an obesity epidemic, but why is it that not everyone is succumbing? Medical science has been obsessed with this subject and is coming up with some unexpected answers. As it turns out, it is not all about exercise and diet. At the centre of this programme is a controversial overeating experiment that aims to identify exactly what it is about some people that makes it hard for them to bulk up.

This episode takes you on an enchanting journey through the vital waterways of Britain and Ireland. From the serene reed-beds of Somerset to the bustling ecosystems of Scotland's lochs, the film unveils the intricate dance of life sustained by freshwater. Marvel at the agility of dragonflies and the aerial prowess of hobbies, witness the arduous journey of Atlantic salmon as they return to their birthplaces to spawn, and observe the fascinating life cycle of the mayfly. Discover the impact of reintroduced beavers in Scotland, creating new wetlands that buzz with life. The episode doesn't shy away from showcasing the challenges these ecosystems face, from climate change to pollution, emphasizing the delicate balance that sustains these vibrant freshwater habitats.
‘Freshwater’ is a mesmerizing ode to the streams, rivers, and lakes that are the lifeblood of the Britain and Ireland isles, supporting a diverse array of life in one of the planet's most beautiful settings.

Professor Brian Cox seeks to understand the nature of time and its role in creating both the universe and ourselves. From an extraordinary calendar built into the landscape of Peru to the beaches of Costa Rica, Brian explores the cycles of time which define our experience of life on Earth. But even the most epic cycles of life can't begin to compare to the vast expanse of cosmic time. Ultimately, Brian discovers that time is not characterised by repetition but by irreversible change. The vast universe is subject to these same laws of change. As we look out to the cosmos, we can see the story of its evolution unfold, from the death of the first stars to the birth of the youngest. This journey from birth to death will ultimately lead to the destruction not just of our planet, but also the entire universe, and with it the end of time itself. Yet without this inevitable destruction, the universe would be without what is perhaps the greatest wonder of all; the brief moment in time in which life can exist.