The game-day chess nutrition guide

Eat your way to up the rating ladder. Grasp the basics of fuelling for chess and what to do on a day of OTB.

This photo is of the Rogue esports team. What a splendid display of professionalism. Very few packaged snacks, in-house-made burritos, yoghurts with fresh fruits, and salads with chicken, nuts, and bananas. The players are taken care of, they don’t have to worry about what to eat, it’s all prepared for them and they can be confident that this food will help them perform. Esports has leapfrogged chess in terms of focus on health and wellness. I want to close that gap. How to eat to improve cognition is now being actively researched, and we have some data points. I have compiled some of the evidence here. What most people want is magic-pill thinking. The special food to eat, or the special food to avoid. Instead, I will give you a key understanding of the basics and some non-controversial recommendations.

Nutrition is one of the most inflammatory domains on the Internet. It is packed with tribalism, cherry-picking of evidence, n=1 statements, and zealotry.
I will aim to write something that will be timeless advice as much as possible, and be true in a few years. If the evidence change, I will change my stance.
Note that in the topic of nutrition it is always possible to find one publication that supports your preconceived bias. That’s why it is more important to use meta-analyses, which gather data from as many published research papers as possible.

I will focus on game-day nutrition, and give you an understanding of what is happening during the day and how to increase your nutrition skills. As usual, we want to close the knowing-doing gap.

The nutritional demands of chess

Nutrition must be tailored to the demand of each specific activity. Running a 200-metre race is different from running a marathon and yet different from powerlifting or competing in an ultra-endurance event. The physiological demands require a particular blend of macro and micronutrients. So what is the physiological demand of chess?

A few years ago a viral ESPN article quoted a scientist giving a crazy number, that a day of OTB chess could use 6000 Calories. – that particular scientist recognised his error and backtracked since, and he didn’t even want the journalist to use that number, but here we are. This number has since been used by many people, even some claiming to give nutrition advice. Of course at the mere mention of that number you can stop reading, what is worth the advice of someone that does not understand the basics enough to realize that this number is clearly wrong?
In any case, the physiological demands of chess … have been measured. It’s actually pretty simple, as we can fit players with a mask that will measure and analyse their breathing output, and this is an excellent way of measuring Energy Expenditure. It is about less than 100 Calories per hour, half the energy cost of walking and comparable to doing light desk work. Just because your heart rate is elevated, it does not mean that the energy expenditure is very high! People have strapped Polar Heart Rate measurement watches onto players and gotten crazy expenditure numbers. These are wrong. Why? Because a heart rate of 130 bpm per minute while doing cardio is not the same as 130 bpm while playing chess, because the stress will elevate the heart rate without any underlying increase in energy expenditure. If there is no ‘chess’ mode on your watch, then the calorie number will be inaccurate. End of story.
As usual, it takes so much effort to debunk misinformation…

Yet, after a long OTB game, we feel tired. Why is that? There is a build-up of mental fatigue.
If you want to know more about mental fatigue, Kostya Kavutsky and I interviewed an expert – we had a very deep dive into all things related to mental fatigue
The brain actually keeps its energy expenditure fairly constant, so not only fuelling the brain should be important but eating an adequate amount of macro and micronutrients to sustain the brain structurally and help cognitive function.

In summary, we need to

  • Sustain the brain
  • Sustain cognitive process
  • No need for a huge amount of calories

And gain skills in the process, not just knowledge.
Let’s see how we do this.

The basics of nutrition and their relevance for cognition


Proteins are the building blocks of bones, muscles, skin, and blood and make hormones and neurotransmitters. Dietary protein may be plant- or animal derived (incl. animal byproducts such as eggs or dairy). Animal-derived proteins contain adequate proportions of all essential amino acids, making them complete proteins. Plant proteins, on the other hand, are incomplete proteins with some exceptions like soybeans. Digestion breaks down proteins into amino acids which have multiple purposes in the body.
The impact of dietary macronutrient intake on cognitive function and the brain, Anne-Katrin Muth, Soyoung Q. Park

The brain has an actual protein content of about 10%. And while for muscle there is a daily protein turnover of 1-2%, for the brain this is about 3-4%. The production of neurotransmitters also depends on amino acids found in proteins. While we do not know the actual amount of protein that is required for optimal brain operation, you should have an adequate high-ish protein amount from your daily physical training. Protein will also make you feel fuller and increase satiety. It is especially important to understand your protein intake if you follow a vegetarian diet.

Skill to improve: Count your protein! Track the amount over a whole week. What is your intake relative to body weight?


Carbohydrates are different types of biomolecules made up of carbon, hydrogen, and oxygen atoms. Plant whole foods provide complex carbohydrates such as starches and fibres that need to be broken down into their constituent sugars. Processed foods, on the other hand, such as snack foods and sweets supply simple sugars. Sugars are already broken down and provide instantly available mono- or disaccharides.
The impact of dietary macronutrient intake on cognitive function and the brain, Anne-Katrin Muth, Soyoung Q. Park

Glucose is the fuel of choice for the brain – (in special circumstances where ketone bodies will be the main substrate) to the quantity of about 130 grams per day. Now after eating carbs, the amount of glucose in the blood will increase and the body will produce insulin which will stimulate the uptake of glucose by the body. Different foods will increase blood sugar in different ways – this is the so-called Glycemic Index (or GI). My own bias before looking at the research myself was to think that a low GI diet should be superior for cognitive function (it might be also superior health-wise). And then I found out that there is no clear evidence of that statement despite the call of a few individual studies. I think this is where it is important to check your own physiology. How do you respond best in-game after a low-GI snack (a banana) or after a high-GI one (a chocolate bar), and how do you feel after 30 minutes, and after an hour. Find what is the best snack for you in-game, whether it is high GI or low GI.

Skill to improve: look up the Glycemic index of your favourite in-game snack. Look up two alternative snacks: one of lower GI, and one of higher GI. Experiment with how you feel throughout a long game.


There are four classes of dietary fats: saturated, trans, mono- and polyunsaturated fats (commonly abbreviated as MUFA and PUFA, respectively). Saturated fatty acids (SFA) are found in dairy and meat products. Processed foods are high in trans-unsaturated fats. MUFA and PUFA are found in olive oil, nuts, avocados, vegetables, and vegetable seed oils. Dietary cholesterol, and unsaturated alcohol is prevalent in meat, eggs, and dairy.
The impact of dietary macronutrient intake on cognitive function and the brain, Anne-Katrin Muth, Soyoung Q. Park

Lipids (fats) are 50-60% of the brain’s dry weight. There is evidence that trans and unsaturated fatty acids are worse for cognition than saturated ones. This shows in the general idea – supported by a lot of evidence – that one should minimise the consumption of highly processed food. This being said, we have no idea of the ideal type and among of fat that is optimal for cognitive function.

Skill to improve: Recognise the amount of highly processed food you are consuming. Log them over a whole week.


Micronutrients are minerals and vitamins. Given that the functioning of neurons is of electrical nature, the minerals required for this are of extreme importance. Rather than getting your micronutrients through supplements, go with a food-first approach and fulfill of your body’s needs through food. Typically, a varied diet of home-cooked food will provide you with all the micronutrients you need.

Skill to improve: Make sure you get a variety of home-cooked vegetables and fresh fruits.


Severe dehydration impairs cognitive function. This is somehow easy to understand. But what about very low dehydration? During a chess game, it’s unlikely that you will lose more than 1% of your body weight through dehydration. I checked two large meta-analyses with … contradicting conclusions. However, a couple of new studies show that mild dehydration might impair cognitive function. I would err on that side and always make sure you have a bottle of water or other light drink on your table. Don’t drink so much that you will need to use the toilet excessively, but always make sure that your urine is clear and not too yellow (which would indicate dehydration).

Skill to improve: Always bring a water bottle and drink a bit from time to time. Take the habit to notice your dehydration stage by checking urine colour.

Meal timings: Breakfast, Lunch and Sleepiness

Feeling sleepy early afternoon after a meal is known as Postprandial somnolence (which means post-meal sleepiness). The causes are not yet fully understood but many misconceptions are going around. It is not due to the blood flow being redirected from the brain to the gut (the extra blood in the gut comes from the muscles and the brain blood flow is tightly regulated) and it is not due to a particular food (no, the tryptophan in turkey isn’t responsible for it). There might be complex neurological causes to it. No matter what the cause is, the impact is clear and strong. One way to avoid this afternoon sleepiness: do not have a heavy meal before your chess game. Especially as the games often start early afternoon. If possible, the best strategy is to have a large breakfast and then, a few hours later, a small lunch. Note that having a large breakfast is good from a circadian point of view, as in the morning your body will be the most apt at dealing with blood sugar (i.e. this is when insulin will function best).

Skill to improve: Check the game time and your lunchtime. Control your lunch to small portions. Get into the habit of eating breakfast on game day.

Dinner and Sleeping

There is conflicting and unclear evidence if a late dinner impairs sleep or not. It might be possible that a late dinner helps to fall asleep but maybe disturbs a deep sleep. From a mental perspective, having dinner with friends, family or colleagues can be a great way to relax and unwind after a long game. Especially, if you had a light lunch (see the previous paragraph) you need to cover your nutrition for the day adequately. I stay on the lookout for further studies in this area.

Skill to improve: Food and nutrition isn’t all biochemistry. Social and emotional aspects are important to keep in mind and dinner can fill this role nicely. Enjoy and unwind at the end of the day.


Just don’t. Even a little bit. It’s poisonous to your body at any dose. And during a tournament, it will destroy your sleep quality. (You might find it easier to fall asleep but your sleep is going to be very shallow and of poor quality.) If you must drink, save it for after the tournament.

Skill to improve: Learn to order a non-alcoholic beer or similar non-alcoholic alternative if you meet with friends and they are all drinking. You will be surprised to see that you don’t feel like an outsider and it is a satisfying drink to have.

Miscellaneous topics not covered

Maybe in further posts, I will cover the use cases of

  • Creatine
  • Caffeine (and L-theanine)
  • Exogenous aids
  • Fasting and alternative diets
  • Any questions you have

The above is not medical advice. Consult a physician and consider your own health and specificities.

Summary of what to do on game day:

  1. Have a large breakfast, and make sure it includes a source of protein.
  2. Have a light lunch.
  3. Be well hydrated.
  4. Eat snacks during games (that you are used to and know that they help you). If necessary bring all the snacks with you for the tournament.
  5. Eat dinner (again make sure you have a source of protein)
  6. Don’t drink alcohol.

Simple, but not easy. Learn skills! Learn to count proteins. To count calories. Learn to recognise the GI of the snacks you consume. Learn to control the portions you take at lunch. And above all, make sure you eat a varied diet of home-cooked food as much as possible.
Foster a healthy relationship with food, and if you struggle: look for help from a medical professional.

To read further:

The impact of dietary macronutrient intake on cognitive function and the brain

Minor degree of hypohydration adversely influences cognition: a mediator analysis

Postprandial Somnolence

The Influence of Glycemic Index on Cognitive Functioning: A Systematic Review of the Evidence

Can Nutrients and Dietary Supplements Potentially Improve
Cognitive Performance Also in Esports?

Nutrition for the Video Gamer

The stress of chess players as a model to study the effects of psychological stimuli on physiological responses: an example of substrate oxidation and heart rate variability in man

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