It's fireworks in the feeding clinic as 24 stone call centre agent Julie meets superskinny caffeine addict Jade. Jade weighs just five and half stone, and is desperate to regain her pre-pregnancy size for the sake of her young son. While Jade barely eats a thing, Julie, whose lack of confidence is stopping her from following her dream to be a schoolteacher, binges on huge platefuls of home cooked food, from massive cream filled curries to cheesy topped shepherds' pies. Dr Christian pushes the diet swappers to look beyond what's on their plates to explore the psychological triggers that lead to their dangerous diets. But Julie goes into meltdown when she's accused of lying about what she eats by Jade. In 'Postcards from America', a new strand of hard-hitting short films featuring morbidly obese Americans, 37 stone Alaina Morgan from Santa Rosa, California, makes a plea to Julie to lose weight before it's too late. Presenter and serial dieter Anna Richardson is two stones lighter than when she two years ago, but admits that she continues to be obsessed with getting the perfect body. In this film she investigates the very latest diet products and exercise fads. The show also takes a glimpse into the lives of three women and one man in the grip of the mental illness anorexia nervosa, following their progress over the series as they explore the causes of their condition under the guidance of eating disorder specialist Dr Peter Rowan.

Emotions run high in the feeding clinic as Dr Christian Jessen pushes calorie-counter Lucy Lee and buffet-binger Leighton Davies to the limit. Lucy weighs in at just under eight stone. She became addicted to dieting after shaking off her post pregnancy weight, and is terrified she'll end up too ill to care for her child. Trying to wolf down Leighton's gigantic portions of take away food brings all of her anxieties rushing back to the surface. Twenty three and a half stone Leighton breaks down when he receives a video message from the morbidly obese Edward Ledesema in Los Angeles, urging Leighton to wake up to the true dangers of his deadly diet. Anna Richardson continues her investigation into getting the perfect body. Desperate for smaller, firmer looking breasts, she meets a top glamour model who gives her some secret tips of the trade. The show also takes a glimpse into the lives of three women and one man in the grip of the mental illness anorexia nervosa. This time the quartet go to supermarket shopping for a lunch consisting of the high calorie ingredients they would normally avoid. But this proves a step too far for Ashley.

Emma weighs just over 85 pounds and is obsessed with her diet; Scott is a non-stop midnight muncher.

Binge eater Wayne swaps diets with fussy eater Lucia. And Anna Richardson tries tower running, ultrasound and infra red, as she bids to get herself a perfect pair of legs.

Junk food addict Andy moves into the feeding clinic with `too-busy-to-eat' Hannah, who battles with Andy's junk food medley as she forces down pizzas, burgers and kebabs. And Anna Richardson tries to get perfectly honed and toned arms.

Supersized Alyson Mawunga, swaps her colossal portions and sugary snacks with superskinny Nick Wood.

In the feeding clinic Louise Knox, queen of convenience food, meets Carly Pitman, who's so busy she never finds the time to eat. Louise weighs 18 stone, nine pounds. She gorges on pizza, burgers, fried chicken and chips, and is worried her weight is hampering her chances of a second child, while also leaving her too tired and unfit to play with the one she's got. Louise receives a shocking video postcard from America, in the form of Laurie who weighs in at a staggering 30 stone, and can't stand up for more than two minutes at a time. Carly, meanwhile, is a tiny seven stone, and consumes a fraction of the vitamins and minerals her body needs. She never finishes a meal and is constantly tired as her body struggles to run on empty. Dr Christian warns Carly that this sort of behaviour, if unchecked, can spiral into a serious eating disorder. The four anorexics are tested to the limit, as they attempt to make and then eat their food nemesis, pizza! And Anna Richardson uncovers a disturbing new procedure in which a patient's own blood is literally sucked out and re-injected into their skin to make it look younger. Anna also heads back to ballet classes, where she tries, and fails to move like a prima ballerina.

Food hater Louise swaps diets with 39-year-old biker Eddie, who needs to change his diet before it's too late. And Anna Richardson gives up on perfection and accepts what she was born with. Food hater Louise Tighe from Hartlepool weighs in at a miniscule six stone 13 pounds. She works long hours as a waitress and barely finds the time to eat. When she does, she eats a few mouthfuls and the rest goes in the bin. Louise bursts into tears as she makes the connection between her bad eating habits and her unhappy childhood. Eddie tips the scales at a whopping twenty seven and a half stone and is a ticking time bomb. With a history of obesity related illness and death in his family he needs to radically change his diet before it's too late. Eddie breaks down when he receives a shocking video postcard from America, in the form of 40 stone Quentin from Hawaii. Meanwhile the four anorexics reach the end of their series-long journey, and celebrate with a three course meal. And Anna Richardson's investigation into getting the body beautiful ends at the beach, as she celebrates her lumps and bumps by running stark naked into the sea!

Dr Christian invites diet swappers back to the feeding clinic to discover how they are getting on with their healthy new lifestyles. Previously superskinny Gillian entered the feeding clinic with Phillipa to see if she could unlock her dysfunctional relationship with food. Has she been able to do this? It's been a year since full time working-mum Heather attempted to curb her enormous appetite. Catch up with her story. This revisit also looks back at the harrowing stories of four brave women who sought treatment for anorexia nervosa. And serial dieter Anna Richardson returns to show a group of friends how to have their cake and eat it.