By: Simon Cooper, Posted on: June 28, 2016
The saying goes that you are what you eat, so when it comes to exam time it makes sense to think carefully about what you are feeding your body. Food is fuel and knowing what to eat and drink ahead of exams can make all the difference to your performance.
A key factor in how well you do in an exam is “cognitive function”, which pretty much means the functioning of the brain. This includes variables such as memory and attention, and it can be easily affected by how much, and what type of food you do or do not eat. So it is logical that to enhance exam performance you want to think about optimising your cognitive function, with diet a key factor for consideration.
So where to start? Well, the first thing to consider – which is particularly important for morning exams – is to eat breakfast. Evidence suggests that breakfast consumption, when compared to skipping breakfast, enhances cognitive function in children, adolescents and adults – and that missing breakfast can impair your cognitive function and exam performance. So you should always make sure you eat something before an exam – ideally about two hours beforehand. It also matters what you eat. In adolescents in particular, our work suggests that the breakfast should be low glycaemic index (GI).
Low GI foods produce a slower rise and lower peak in blood glucose concentration after eating which is believed to be beneficial for cognitive function. For example, muesli and porridge (with no added sugar I’m afraid) would be an ideal start to the day. A number of things can also help to reduce the GI of breakfast, such as adding milk. Milk promotes the release of insulin, the key hormone in glucose uptake which helps to lower our blood glucose concentration. Adding an apple can also reduce the GI of our breakfast.
The breakfast should also be reasonably high carbohydrate, given that glucose (from carbohydrates) is the main fuel used by the brain. This could include foods such as breakfast cereals, toast and porridge. However, you may also want to think about adding in some protein as it helps us to feel fuller for longer.
Because the last thing you want is for your stomach to rumble halfway through an exam, a breakfast containing both carbohydrate and protein may be the best course of action – such as scrambled eggs on wholegrain toast. It’s also probably best to avoid high fat foods, such as a full English breakfast, as they can make us feel tired.
Alongside breakfast, it is also very important to ensure that you stay hydrated. Lots of people do not drink enough and evidence suggests that dehydration impairs our cognitive function leading to poorer exam performance. In terms of what to drink, water is always a good call, as lots of “energy drinks” and fruit drinks contain lots of sugar.
Something also worth considering is caffeine. Caffeine has very well documented effects on cognitive function and alertness – so you may want to think about boosting your caffeine intake. However, this must be done with slight caution – don’t over do it. A very large dose of caffeine can also have negative effects, and lead to you being unable to concentrate (and wanting to get up and run around the exam hall). But the opposite can also be true, especially in habitual caffeine consumers. If they abstain from caffeine completely they may experience negative consequences.
So that’s your nutritional pep talk for morning exams, now what about for an afternoon one? Well, similar things hold true. You want to be eating a lunch based on carbohydrate and protein (consumed around two hours before the exam if possible) and to ensure that you stay well hydrated, with moderate caffeine intake.
It is also worth pointing out that nutrition is not a one size fits all science – what works for one person may not work for another. So use these tips as general guidelines. My greatest recommendation would be to “practice” these exam nutritional strategies, to make sure they work for you. It is better to find out in advance, rather than on the day, that you can’t stomach a big bowl of porridge at seven in the morning.