Keep away from junk food! You may feel like you deserve a treat, or that you don't have time to cook, but what you eat can really have an impact on energy levels and focus. Keep your body and brain well-fuelled by choosing nutritious foods that have been proven to aid concentration and memory, such as fish, nuts, seeds, yogurt and blueberries. The same applies on exam day - eat a good meal before the test, based on foods that will provide a slow release of energy throughout. Sugar may seem appealing, but it won't help when your energy levels crash an hour or so later.