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?

Reporter Dr. Graham Phillips examines the effects of meditation in his own life, and the medical evidence of how it affects those who practice it. Can meditation literally make your brain younger?

Jacoba Ballard was an only child, conceived via donor sperm, who always dreamed of having a brother or sister. When an at-home DNA test led her to the discovery of not one but seven half-siblings, she realized that she had stumbled across a major finding.
Jacoba discovers a shocking scheme involving a former Indianapolis based fertility doctor, who, in a case of fertility fraud, used his own sperm to impregnate dozens of unsuspecting patients.

A look at how the Sun was formed and how it could potentially die; its physical composition; how it makes energy; and the nature of solar eclipses, solar flares and sunspot activity. Behold the sun and all of its glory. Learn all things about the sun ranging from its beginning to its death. Also learn about how stars work in general and MUCH, MUCH more.

This episode of the documentary series focuses on the new giants, the heavyweights of the dinosaur world. It is only in recent years that experts have unearthed the biggest dinosaurs that ever lived. One monster eclipsed all others; more than seven times as heavy as diplodocus was the immense argentinosaurus - a single backbone was bigger than a human. For years, these giants were considered immune to attack from any predator - until the discovery of mapusaurus, a new giant killer whose fate appeared to be inextricably linked to argentinosaurus

The series, depicted by state of the art CGI techniques, and applying the laws of life on Earth to the rest of the galaxy, blends fact with science fiction and conceptualizes what alien life might be like on other planets.
In the prologue, astronomer Didier Queloz makes an appearance to discuss the discoveries of exoplanets and how they are analyzed in the real world. In Episode 1, the fictional world imagined is Atlas, a world with higher gravity than Earth and a thicker atmosphere leading to airborne creatures. In explaining the aliens of Atlas, the episode also explores the handicap principle in insects, and shows a rehabilitative form of falconry as captive falcons are trained to live in the wild.