With the festive season looming, Ruth Langsford investigates which diets work best for anyone who wants to lose weight fast. Under the supervision of Dr Amir Khan, 12 overweight food lovers go on some of the most extreme diets out there. They include meat-lover Emma, whose love of sausage sandwiches is not helping, and Lynne, whose large takeaways covered in salt have pushed her into the obesity category. They and the others agree to try to shift 14 pounds in a single month.