Any student sitting their GCSEs at the moment will know the feeling.

You've overslept having been up late the night before revising, you're running late and have got to be in the exam hall by 9am. In a bid to save time, you skip breakfast but, halfway through, your stomach begins to rumble and you can feel the marks slipping away as you struggle to concentrate and hunger takes over.

Teachers at Smithdon High School knew the problem. So, following in the footsteps of Costessey's Ormiston Victory Academy, which shipped in hundreds of bananas to boost pupils' brain power, chefs at the Hunstanton school went one step further and rustled up some bacon for a mouth-watering butty.

The result, said headteacher Jonathan Goodchild, is that students who were once a bit sleepy were now bursting with enough energy to tackle that two-hour English literature essay or maths paper containing tricky sums, equations and algebra.

'It is a lot to get through when you have not woken up properly and the bus journey was often sending some of the students to sleep,' he said.

'They have really appreciated the hot drink and food. They said it helped to wake them up and for many who had nothing to eat before they came into school, they had more energy to sustain a two-hour exam.'

Nutrition consultant Susan Fletcher, based near Cromer, agreed that it was 'absolutely brilliant' to give students something to eat.

However, instead of a greasy bacon bap, she recommended slow-release carbohydrates to sustain their energy levels for the duration of the exam, perhaps with a peanut-butter sandwich or beans on toast.

Jane Rose-Land, a nutritional practitioner from Shouldham, added: 'If I were going to suggest something I'd say boiled eggs – but I don't think that's going to be very appealing to kids!'

Youngsters tucking into their sandwiches before yesterday's two-hour GCSE physics exam agreed that the extra food helped to boost their chances of a top grade.

Charlie Rogers, 15, said: 'I don't have any breakfast before school as there isn't enough time, so by the time the exam starts I am getting really hungry and can feel my stomach rumbling. I am anxious before the exam and not having anything to eat makes it worse.'

His friend Matthew Williamson, also 15, added: 'It helps as you can focus easier in the exam. It helps to ease the nerves a little bit.'

As Mr Goodchild said though, the school will only know whether the offer of a tasty sandwich has worked in August, when pupils discover their results. 'I would be really interested to see whether it translates into even better performance in our exam results this year,' he added.