An hour spent wrestling with a sudoku puzzle can burn as many calories as are contained in a chocolate chip cookie, it has been claimed.
Mental exercise is said to burn up to 90 calories an hour – that’s as much as two Jaffa Cakes or a bag of ready salted French Fries.
Mental agility expert Tim Forrester published the claims on brain training website cannyminds.com, which states that giving the brain a workout burns calories in the same way that a workout in the gym does.
He said: "Our brains require 0.1 calories every minute simply to survive," When we do something challenging such as a puzzle or a quiz we burn through 1.5 calories every minute."
The brain is made up of an estimated 100 billion neurons that communicate with each other. The neurons extract sugar glucose and oxygen from the blood to create neurotransmitters – chemicals that relay these messages.
An hour spent solving the brain-straining Japanese number puzzle would mean you could indulge in a number of treats, including: