Overview: Takeaway addict Chris Longley swaps diets with meal-skipping hairdresser Nathan Smith - and gets a shock when he is sent to stay with a 32st American man whom doctors believe has five years to live. A 19-year-old reveals why his disordered eating has caused him to lose 11st in nine months, and Christian Jessen visits an overeaters' support group in Evansville, Indiana (Christian Jessen)