Dr Christian Jessen checks up on diet swappers one year on.

Darryl from Derbyshire was a hefty 33 stone, and was keen to lose weight in a bid to be more active with his two young sons. The self-titled 'Blobbie Williams' lived on fry-ups, roast dinners, crisps and kebabs - often all in the same day. Darryl swapped with London mum Yasmin, whose diet was free of wheat, dairy, gluten, lactose and preservatives . Yasmin hoped to gain more curves and boost her energy.

London-based jazz singer Sandra was desperate to lose weight to combat her chance of developing diabetes, which runs in her family. She met seven-stone Tatiana in the food clinic. Tatiana, from Brighton, hated her skinny body, but couldn't bring herself to eat anything that wasn't lean and fat-free. How has the last year been for them?