brain) and keep you well hydrated. And by the way, coffee, caffeinated beverages and energy drinks do NOT count as water: in fact, these drinks tend to induce dehydration because they increase urine production, and energy drinks may produce rebound fatigue after initially triggering alertness.
When feeling worn out after a long day in university and needing an instant energy boost that lasts, a healthy snack containing protein and a complex carbohydrate (found in in whole-grain products) is a great option. This is because the combination of protein and a complex carbohydrate (which requires more time to get digested than simple carbs) helps increase and maintain your blood sugar level.
The same concept applies to your breakfast routine: eating a high-fiber (whole-wheat toast or high-fiber cereal), carbohydrate-rich breakfast will provide you with energy for both short- and long-term use. Studies have shown that high-fiber, high-carb meals provide the highest level of alertness in the period between breakfast and lunch.
Now that we got dietary habits covered, we need to tackle physical activity and rest: You may feel worn out at one point during the day; a short (around 10-15 minutes) brisk walk can immediately refresh you.
You may also want to make rooms for short breaks (around 5 min) while studying: every say 2 hours, get off your desk and go to another room (new scenery), chat with your family or friends, then go back to your task. This will increase your ability to focus as well as your efficiency.