Supersize Vs Superskinny

Dr. Christian visits McAllen's mortuary, which is having to be supersized with wider doorways and autopsy tables. In the feeding clinic, LJ Marley, a takeaway addict who tips the scales at 24 stone, with a 59-inch waist, swaps diets with Katie Reeve, whose childlike portions see her weigh in at a paltry 6st 11lb.

In the feeding clinic, Joanne Leadley goes head to head with Ross Clarke from Cardiff. Ross is a meal dodger who never finds time to eat, while Joanne is a giant-portion gorger. Their swap is packed with drama, tantrums and tears. Dr Christian shows Ross the damage his diet is doing to his body and sends Jo to Georgia, America, to meet a woman whose life has been destroyed by overeating.

Forty-two-year-old super snacker Julie Menzies swaps diets with 24-year-old fussy eater Zoe Hughes-Blinston in an emotional encounter. Dr Christian discovers how the funeral parlour in America's fattest town copes with bigger and bigger bodies. And journalist Emma Woolf investigates the little known world of male eating disorders.

Facing off in the Feeding Clinic is 24-stone takeaway addict Craig Nellies and superskinny cola addict Simon Tacaks, who's just too lazy to bother to eat. Dr Christian shows skeletal Simon how concentrated amounts of the chemicals found in cola can cause extreme damage to teeth. In America's fattest town, Dr Christian visits a patient suffering chronic wounds and organ damage.

There's a tense and emotional swap in the feeding clinic as teenage comfort eater Victoria Madden goes head to head with fussy food avoider Hannah Pidgley, whose picky eating has already led to her being diagnosed with malnutrition. Hannah's terrified that her terrible diet is wrecking her fertility and her dreams of being a mum.

Twenty-stone comfort eater Julie Henry swaps diets with coffee addict Dougie Reid. Emma Woolf explores the importance of the early diagnosis of eating disorders. And in America, Dr Christian takes a ride on a bus that's helping Texans battle the bulge.

It's all-out war as round-the-clock snacker Emma Cain goes head to head with Robert Musgrove, who can't be bothered to eat. Dr Christian shows lager-guzzling Emma just what her favourite tipple is doing to her body. In America's fattest town he visits an after-school scheme that aims to help combat childhood obesity.

Pizza delivery driver Thomas Barnes weighs 27 stone 10 lbs, largely due to his weakness for pizza. Glamourous granny Linda Chik loves fruit and veg but doesn't eat enough for her busy-bee lifestyle, so weighs in at only seven stone. Before they swap diets, Dr Christian prescribes a supersized wake up call for Thomas - sending him to visit 35 stone Robin Jones from Missouri.

The show revisits three of last year's feeding clinic inmates - meal dodger Nathan Smith, takeaway king Chris Longley, and convenience queen Jo Palmer. One year on, have they managed to ditch their dreadful diets for good? Plus, it revisits Dr Christian's time in Evansville, Indiana - the US city that topped the polls in 2011 as America's Fattest.

The show catches up with sugar fan Hayley Payne and snackaholic Geoff Milton, one year after they met in the feeding clinic. Have they managed to change their terrible diets for good?