Superskinny size zero Louise Sapsford faces up to supersize Desroy Gordon's torturous diet of non-stop takeaways. Louise comes to terms with the fact that size zero is not a good look and changes her eating habits for good.

Superskinny Alex must swap his diet with Tracy, who has a mouth that's constantly on the move and weighs in at over 20 stone.

Underweight and overweight eaters take part in an extreme diet to either increase or decrease their weight.

Yasmin is forced to eat large amount of food while her counterpart, Darryl, must endure a lactose, wheat, sugar and fat-free diet.

Amy Jo spends five days in the feeding clinic learning to eat more; Andy learns to survive on a limited calorie intake.