In the feeding clinic this time is Caribbean chef Gary Tomlin, who tips the scales at 21 stone eight, and Amy Simons, whose meal-skipping bad habits see her weigh in at eight stone three.
Before they swap diets, Gary goes to America for some shock therapy, where he meets 36-and-a-half stone Nary, who is paralyzed from the waist down, has to be washed in the garage with a hose, and has terrible open wounds that struggle to heal.
Dr Christian visits Las Vegas, the heart of where it's all going wrong with food in the USA, and joins the Fat Interceptor Team, who are battling to save the city's sewers from a tidal wave of fat.
And former anorexia sufferer Emma Woolf continues her investigation into the hidden world of eating disorders as she uncovers the secret world of pro anorexia websites
