This is a question no doubt many people are asking themselves around this time of year, when fad diets and gym memberships are at their peak. In this programme, Dr Xand van Tulleken and dietician Hala El-Shafie help six people go on the most hyped and written about diets on the market to see which works best. In tonight's episode, we meet diet crashers Emma and Kaye, who have ten days to slim down for a day at the races, so Emma tries out the baby food diet, consuming up to 14 jars of it a day. Elsewhere, Eve and Kate go on six-week dieting plans before their holidays, with Eve trying out a bland diet designed to minimise gut irritation with low-fibre and low-fat foods, while Kate is given the champagne diet and can indulge in one glass of bubbly per day, accompanied by strictly calorie-controlled meals. A glass of champagne a day? Think we'd rather some chocolate.