Chancellor and trendsetter: George Osborne is rocking a trendy new Jawbone 'Up' wristband

It is designed to help users sleep better, exercise more effectively and stay away from unhealthy food

Suit. Check. Tie. Check. Finely-starched shirt. Check. But, hang on, what was that hanging off Chancellor George Osborne's right wrist this morning?

Appearing in front of a committee of MPs this morning to discuss tax and spending policies, the Chancellor of the Exchequer was rocking a trendy new Jawbone 'Up' wristband, which is designed to help users sleep better, exercise more effectively and stay away from unhealthy food.

It is unclear whether the 42 year-old will in future be warned off eating burgers and chips, famously Osborne's eve of spending review meal of choice, by the £100 gadget.

But the wristband can be programmed to count calories by scanning food barcodes and pops up with advice for wearers on selecting healthier options. It monitors their exercise through motion sensors and GPS tracking, while also helping users see how deeply they are sleeping.

For those who have time for a siesta in the working day, it can also set alarms to mark out the perfect length of time for an afternoon nap. The Up connects to a smartphone app to relay the round-the-clock information.

Gwyneth Paltrow has recently been spotted wearing one, but it's not just the Iron Man 3 actress and Mr Osborne who have taken to wrapping the bendy rubber strips around their wrists.

After his session at the Treasury Select Committee today, Mr Osborne told journalists that Education Secretary Michael Gove had also taken a shine to the Up, leading to further questions about whether cabinet ministers were searching for ways to get to sleep at night.

“I always sleep well,” said Mr Osborne. “It was a birthday present. It measures how far you walk but it also measures your sleep patterns, your deep and light sleep. I was pleased to note that Michael Gove was also wearing one.”

Jawbone, the Up's manufacturers, believe the more users monitor their fitness, the more likely they are to take steps to switch to healthier lifestyles.