According to Play.com, which released the pre-sales figures, that shows Brits are “fanatical to get fit” as the summer approaches.

The entire stock of Wii Fit sold out in a single day thanks to pre-orders, which puts it in a good position to become the fastest selling Wii game ever.

“Nintendo has outstripped all previous records on Play.com by selling out its entire allocation in one day,” a press release for the ecommerce website said.

“Launching in the UK 25 April, Play.com has been overwhelmed by demand for the new fitness game.”

The game debuted in Japan four months ago, where the exergame sold more than one million copies in the first month, in a nation that owns around five million Wii consoles.

Play.com said the game sales mirrored a 38 per cent increase in diet book sales since the clocks went forward on 30 March.

“Longer, lighter days have helped boost pre-summer diets, especially with 95 per cent of New Years diets having failed by March,” a Play.com statement said.

“Strictly Come Dancersize, Davina and Natalie Cassidy workout DVDs are shifting by the bucket-load selling three times the normal volume in the last week.”

Gian Luzio, head of games at Play.com, said he hoped the website could keep up with demand.

“We are expecting more stock before launch,” Luzio said.