Secondly, your body needs carbohydrates and fats that fuel the brain and muscles. You should opt for slow-burning carbs like potatoes, rice, oats, or whole-grain bread to avoid fluctuations in energy and concentration. Healthy fats are a good source of slow release energy as well, and will also help your nervous system to function well. Good examples of healthy fats would be avocados, eggs, nuts, seeds, olive oil, or butter.