Writing in the Christmas issue of the BMJ Dr Nathan Grills, from Monash University in Australia, says that Santa should swap his reindeer for a bike or walk and ditch the mince pies in favour of fresh vegetables.

After conducting a review of literature and web-based material to assess Santa's potential negative impact on public health, Dr Grills found that Santa encourages not only unhealthy foods but also promotes drink driving.

The tradition of leaving Santa Claus a brandy to wish him well on his travel, with a few billion houses to visit Santa would soon be over the limit, says Dr Grills.

While more research is needed before calling for authorities to regulate Santa's activities, Grills proposes a new image for Santa — a slimmed down version on a treadmill.