Whenever I play long tournament games, I find that I drink simply enormous amounts of water, far more than my typical rate in daily life (and maybe even more than when I am unusually physically active). I don't do this deliberately, or with any purpose in mind; it just seems that my body desperately seeks hydration when I play chess. I know that some famous players swear by particular drinks during games, e.g. Boris Gelfand during his recent match with Anand talked about an energy drink that he always has in his thermos, and Magnus Carlsen seems to keep plenty of OJ around:

Carlsen OJ

More generally, what I'd like to get here is this:

Pointers to any studies concerning the advantages or disadvantages of the consumption of particular foods or drinks during sustained, concentrated mental activities or competitions like chess (but not necessarily chess).

One interesting read I stumbled on is FM Mike Klein's article "The Grandmaster Diet," which references some scholarly studies related to this matter, as well as items such as a survey by Roberto Baglione of the nutritional habits of 72 GMs and WGMs, which includes anecdotes like the following:

"[GM John Fedorowicz] won’t eat a meal if he cannot complete it at least two hours before a game (according to Fedorowicz, GM Walter Browne used to advertise a free steak dinner to his opponent, with the caveat it had to be eaten right before the round). ... Fedorowicz almost always shuns food during games as well, though he did confess to eating a piece of cheese during a seven-hour round at a U.S. Championship several years ago.

I'd appreciate pointers to any other reliable sources that touch on this general topic of food and drink consumption during activities like chess.

  • I wasn't sure how to tag this question; please feel free to add more as appropriate.
    – ETD
    Commented Sep 20, 2012 at 8:49
  • A side note on this. I do my chess practice in the early morning and late night when it's difficult to concentrate (simply due to a busy schedule). It's hard for a few days, but you quickly learn how to think even if your brain is tired. This works well for dealing with different sugar/hydration levels as well. When you aren't tired, chess feels effortless and you can fly through games. So, concentration exercises can help. It's also good to fast occasionally (or even regularly, if you are into that) so that your body learns to deal with dips in your glucose levels.
    – Jeff Davis
    Commented Sep 21, 2012 at 15:37

2 Answers 2


One of the problems is that in the human body, the thirst and hunger mechanisms are not always clearly defined, so that when you are hungry you can feel thirsty, and vice versa. I would posit that you are likely low on circulating glucose, and mistaking hunger for thirst.

The brain uses up vast amounts of glucose while kicking over, and while there haven't been any physical studies of the amounts used during concentration (at least not that I can find in humans, there are some in rats), it is known that higher concentration uses more glucose.

There have been numerous studies that show meal composition and timing have an effect on both mental and physical performance, with breakfast being an important component. Here are a couple of those studies (one for physical, one for mental):

Cognitive Performance

Physical Performance

I recall seeing a study that suggests sweet taste (such as hard candy, etc.) can also trigger the body to release extra glycogen, but I don't recall where.

I would suggest that eating a balanced, healthy breakfast the day of matches, and mild snacking throughout the day (Other studies have shown that mental performance can be impaired immediately after meals - which is likely where the GM interview from the study you cite comes from) will help keep your body well supplied.

I generally suck on hard candy, or (since I also do endurance athletics) I have something like a GU gel or soft chew, which is basically quickly digestible, 100 calorie foods that help fuel the body during performance. You can find various types (Gels, soft chews, drink mixes) at most cycling/endurance stores (REI, multi sport stores, etc.)

Experiment a bit and find what works best for you, each individual is different. I would suggest that high sugar drinks (such as orange juice, etc.) are ok if you don't gulp it and are done, but rather sip throughout. Otherwise you provoke other responses in the body that result in glucose spikes and dips, which won't help.

  • Interesting stuff, especially the "mistaking hunger for thirst" possibility. Thanks for the info! Not to sound too picky, but do you happen to know of any studies, similar in topic or content to that from your first link on cognitive performance, which aren't behind a paywall (for the benefit of those who don't have, say, an institutional subscription to that journal)?
    – ETD
    Commented Sep 21, 2012 at 16:34
  • @EdDean - Ah, bugger. I forgot about that. I don't, but if you cut/paste the title into google scholar, you can sometimes find free sources. Most of the time the abstract also has the conclusion, so you can at least get the gist of it.
    – JohnP
    Commented Sep 21, 2012 at 18:57
  • For those interested in the Breakfast Study on 10 Year Old Students, you can request a full-text copy of the paper from the authors by going to: researchgate.net/publication/…
    – jaxter
    Commented Oct 18, 2016 at 20:43

Here is an article I came across a while ago.

This is probably the key part:

Chess players should try to have breakfast daily.

Avoiding “heavy foods” or foods of difficult digestion before games must be adopted as a regular habit for chess players. The last “main” meal before a game has to be had at least three hours in advance. If a player wishes to have something to eat nearer the time of the beginning of a competition (one or two hours before, e.g.) he/she should choose among fruits (whole ones, fruit salad or juices, raisins), cereal bars, pretzels, cookies, low fat yogurt with fruit or cereals, sports drinks.

During the games, it is recommended fluid ingestion, and, if the chess player wants it (or when the game becomes long), solid foods. Mineral water, fruit juices, tea, coffee, sports drinks, cereal bars, fruits, raisins, dry fruits (almonds, e.g.), chocolate, cereal cookies, can be chosen. In all cases, moderate quantities should be taken.

The best strategy to hydration is to drink small quantities at regular intervals, instead of greater quantities at a few intervals, and avoid being thirsty. The same indication should be followed during board training and physical activity. It is also important to begin the activity properly hydrated.

  • Thanks, this is the Roberto Baglione survey mentioned in the question.
    – ETD
    Commented Sep 21, 2012 at 9:06
  • OK. I see. I did not realize this at the time of posting. Sorry.
    – Akavall
    Commented Sep 21, 2012 at 19:12
  • 1
    Oh, I didn't mean that as a complaint; I'm glad you've given a link to it here (+1). (In fact, I hadn't yet bothered looking into whether it was available online, and I'm happy to learn that it is.) I was just making the connection explicit for the sake of fellow readers once I noticed that's what this is.
    – ETD
    Commented Sep 21, 2012 at 19:21
  • Oh, I see. Than I glad that my post was useful.
    – Akavall
    Commented Sep 21, 2012 at 21:53

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