In the second of this four-part series, Jacques charts the story of the fitness industry and examines the links between exercise and weight loss. He speaks to the former Global Head of Health at PepsiCo and poses the question: why does the food industry put so much money into promoting exercise? Peretti also examines some of the pharmaceutical solutions available for weight-loss, as he tells the story of the race to find a safe and effective pill to make us thin.

• Jacques Peretti