This documentary meets six extraordinary weight loss champions, who lost 80 stone between them, to find out what happened to them next. After they collected their prizes and the press photographers left, did they manage to keep the weight off? And, at a time when around 60% of people in the UK are overweight, a ground-breaking science study on a TV star who lost 17 stone reveals the body's incredible but little-known biological response to dieting that sabotages our efforts to keep weight off.