I have the motivation, but I still feel too tired to continue studying!
There are times when a student is motivated to dedicate their day for intense study sessions. But within the first hour of studying their concentration drops rapidly, their body starts aching, and their minds become foggy. All for what reason? It’s not their method of studying or lack of sleep. Rather, it’s something that is constantly overlooked in our daily lives.
The food we eat.
Most students don’t realise this, but your brain needs a steady supply of energy to stay focused. And the food you eat before studying can either help you concentrate, or make it nearly impossible.
The good news? You don’t need a complicated diet or expensive “superfoods.” Just a few simple changes can make a noticeable difference.
Focus-group and interview studies with adolescents preparing for exams often surface the same pattern: mid-session fatigue is blamed on willpower or sleep, while what they ate in the hour before revision goes unmentioned until meals are tracked alongside focus.3 That gap between feeling undisciplined and fueling poorly is one reason nutrition belongs in any serious study-skills conversation.
Here’s what to know, grouped into three moves you can use before your next revision block.
1. Why Food Matters More Than You Think
Your brain uses glucose (a simple sugar molecule) as its main source of energy. Glucose is generally found in the majority of food we eat, and eating glucose has shown to improve cognitive performance and improve attention in adults.1 So, if you refrain from glucose entirely you would feel negative effects such as fatigue and dizziness.
But just as it is bad to consume too little glucose, it is also bad to consume a lot. A sudden increase in sugar can lead to a spike and crash effect, resulting in poorer performance and lower energy.
That “I can’t focus anymore” feeling halfway through studying? It’s probably just an energy crash right after a sugary snack.
What you want instead is steady, sustained energy, the kind that helps you stay alert for longer without burning out. And the key is balance.
Comparative work on how different dietary sugars affect cognition has found that not all “energy” hits the brain the same way: rapid sugar intake can lift performance briefly and then leave attention worse than baseline, which matches what many students describe after biscuits or sugary drinks at the desk.2
2. What to Eat Before Studying
The sudden spike in glucose from sugary food is usually the main cause of fatigue and poor performance. So the goal is simple: combine foods that release energy slowly and keep your brain fuelled.
Slow-Release Carbohydrates
Focus on food with a low glycemic index (GI), which means it gives you a gradual, steady supply of energy instead of a sudden, quick spike.
Good options include:
- oats
- Whole grain bread
- Brown rice
These help you stay focused for longer periods without suddenly crashing.
Protein for Sustained Focus
Proteins are the building blocks to essential molecules in your body. It helps keep you full and prevents energy dips.
Good options include:
- eggs
- Yogurt
- Peanut butter
Tip: Pairing protein with carbs = more stable energy.
Healthy Fats for Brain Function
Your brain actually benefits from healthy fats. They support concentration and mental performance.
Good options:
- nuts
- Avocado
- Butter
You don’t need a lot, just small to moderate portions make a difference.
Quick Energy (In Moderation)
Sometimes you need a small boost, especially before a short study session.
Good options include:
- Bananas
- Dark chocolate (small amount)
These are great, but don’t rely on them alone. They are just to satisfy those random cravings.
Hydration (Underrated but Critical)
The most important, yet overlooked requirement is hydration. Even mild dehydration can affect concentration and overall performance. So always make sure you:
- Drink water before and during studying
- Don’t wait until you feel thirsty
You’d be surprised how often “lack of focus” is just because you forgot to drink water over the last hour or two.
When Should You Eat?
Timing matters just as much as what you eat. It is recommended that you:
- Eat 30–60 minutes before studying
- Avoid studying immediately after a heavy meal
- Have a light snack nearby if it is a long session
Think of it as prepping your brain before you start.
Simple Study Snack Ideas
It’s alright to occasionally eat some snacks. You don’t need anything complicated. Here are some easy combinations:
- Oats + banana
- Toast + peanut butter
- Yogurt + nuts
- Eggs + whole grain bread
They are quick, affordable, effective, and more importantly, tasty.
3. What to Avoid Before Studying
As mentioned before, some foods (like too much sugar) can make studying harder as it can lead to poorer attention and performance.2 So try to avoid the following:
Sugary Snacks
- Candy, biscuits, sugary drinks
Cause rapid energy spikes followed by crashes
Heavy, Greasy Meals
- Burgers, pizza, fries
Make you feel sluggish and sleepy
Too Much Caffeine
- Multiple coffees or energy drinks
Can lead to anxiety, jitters, and poor concentration
The Most Important Thing to Remember
Even if you improve your diet and eating habits, you have to remember that food won’t magically make you smarter.
It will not replace active study techniques like:
- Practice
- Past papers
- Spaced repetition
But it will make those things easier to do. So think of it this way: Good nutrition doesn’t guarantee success, but poor nutrition almost guarantees struggle.
Conclusion
If you’re constantly feeling tired, distracted, or unfocused while studying, don’t just blame your discipline. Take a look at what you’re eating.
A small change in your diet won’t transform everything overnight, but it can be the difference between:
- Struggling to focus for 20 minutes
- And getting through a solid, productive study session
And sometimes, that’s all you need to start improving.
References
- Setoguchi Y, Tsukiashi M, Maruki-Uchida H, Iemoto N, Ebihara S, Mato T. Effects of Glucose Tablet Candy Ingestion on Attention Following Smartphone Use in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Crossover Trial. Foods. 2025;14(24):4233. doi:10.3390/foods14244233
- Ginieis R, Franz EA, Oey I, Peng M. The “sweet” effect: Comparative assessments of dietary sugars on cognitive performance. Physiol Behav. 2018;184:242-247. doi:10.1016/j.physbeh.2017.12.010
- Chin YS, Mohd Nasir MT, Mohd Sobry S, et al. Eating behaviours among urban adolescents: a qualitative study. Public Health Nutr. 2018;21(8):1473-1481. doi:10.1017/S1368980018000718