Students who fuel their revision with numerous cups of coffee and sugary snacks are more likely to fail their exams than those who stick to a healthy diet, say experts.
Revision and exams set up a vicious circle of stress which is made worse by a bad diet. Sweets, chocolates and energy bars give a short-term energy boost which is followed by a sharp drop in blood sugar levels, damaging concentration, memory and ultimately exam performance.
Even fruit juice, normally considered a healthy option, should be diluted by half with water because of its high sugar content.
"As the old saying goes, 'You are what you eat', so if you do not want your brain to turn to mush during exam time, you need to give your body a break and feed it some healthy food," says Fiona Beckett, author of Beyond Baked Beans: Real Food for Students.
Her website www.beyondbakedbeans.com includes advice from health writers and experts from the British Nutrition Foundation and British Diabetic Association. Students should eat little and often rather than having one big meal a day.
Michael van Straten, alternative health specialist, suggests a lettuce sandwich half an hour before bed. "It combines the opiate-like chemicals in lettuce with the sleep-inducing effects of carbohydrates," he says.
Pre-exam meals should be high-carbohydrate but also include protein to slow digestion. Porridge is suggested for breakfast. And lunch? Beans on (wholegrain) toast.