Although he's always been able to squeeze his sizeable bulk down chimney stacks, it seems that Old Saint Nick has been losing weight when making his way through letterboxes. Santa Claus, whose Christmas Eve deliveries are fuelled by countless mince pies and pints of Guinness, has shed more than 12 kilos in weight in the last decade, according to a survey.

A new study of Christmas cards carried out by Clintons, a UK stationery chain, has revealed that Santa Claus has shed several pounds in recent years. In addition to his svelte figure, Santa has also changed colour – his rosy cheeks have become even pinker, while the shade of red of his costume has deepened to a dark burgundy.

James Horne, who analysed 20 years of Christmas cards, made the discovery, saying: “Depictions of him have become slimmer — possibly because we have become more weight conscious and into healthy eating.”

“We estimated his size in hundreds of cards and identified depictions have notably slimmed him down in recent years. He’s not as fat and round as he once was,” he added.

It isn’t just Santa’s waistline that’s disappearing from view – the survey also found that the gift-giving Kris Kringle appears on 5.6 percent fewer cards than previously. Another Christmas staple, the robin, is also waning in popularity, falling by 23.4 percent in the last 10 years.

Santa and the bird’s loss has been snowmen’s gain - Frosty and friends are now on 17 percent more cards than before.

The first commercial Christmas card was designed by John Callcott Horsley in 1843. The design featured three generations of the same family toasting a happy Christmas to the card’s recipient. 

Sir Henry Cole's design [Wikipedia Commons]