Xand van Tulleken and Helen Lawal oversee proceedings as three more pairs road test some of the most popular and talked about diets. Jonno and Alfie have two weeks to slim down for a family barbecue, Sonal and Surekha go on six-week dieting plans to lose weight for an engagement party, and twins Michelle and Mandi want to trim some excess for a black-tie event in four months' time. Xand also investigates investigates what happens when people are hungry and angry, and pits alcoholic drinks against one another to find out which is the worst for calories.