The Food Hospital experts employ cutting-edge research as they treat a 19-year-old dancer with Crohn's Disease, an ex-soldier with a sleep disorder, a man whose sperm needs a boost if he's to father the child he wants so much. And one of Britain's growing numbers of morbidly obese teenagers is taught how to approach food again after her gastric bypass surgery. Dr Pixie McKenna discovers the truth about sports drinks: Do they really boost energy or are they an expensive irrelevance?