Fish. Fish contains omega-3 fatty acids. Since our brain is made up of mostly fatty tissue, eating things that contain healthy fatty acids will help us to stay more alert.

Apples. The peel of an apple includes the antioxidant quercetin, which helps to enhance memory function, an important tool when it comes to studying.

Spinach. Usually when someone is hungry, they don't instantly think of spinach, but spinach has a lot of folic acid in it which has been shown to reverse memory loss.

Natural sugars. Sugar can help you to stay alert if you are feeling tired and unfocused. Something that contains natural sugars, such as an orange, should be best.

Broccoli. Broccoli contains Vitamin K, which has been shown to improve brain power. If you don't like the taste of broccoli, you can do what your mom used to do when you were a kid and smother it in cheese.

Eggs. You cannot focus while taking exams if you are hungry. Eggs will not only help you focus, but they are also high in protein and are good at making you feel full.

Peanut butter. This is one to get excited about, because who doesn't love peanut butter? Peanut butter contains healthy fats and is chock full of protein. It is good at keeping you full for a long time.

Water. Keeping your brain hydrated is vital. If your brain becomes dehydrated, it will grow tired and start to slow down, making you irritable. If you just keep sipping water, then you will have a boost of energy.

Tomatoes. Tomatoes contain lypocene, which is an antioxidant that helps protect against free radical damage to cells which can cause dementia.

If you need help staying focused, all you have to do is eat one of these things and you will be fine!