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Can What You Eat Increase Your Concentration?

Are you prepared for the return of work-life at the office again?

Key points

  • After being out of the office for so long, we may be even more sensitive to common distractions when returning to the workplace.
  • The consideration of what to eat may be important when aiming for deep focus at work.
  • More research is needed to clarify the impact of a low-carbohydrate diet on concentration.

Now that we are moving back to our pre-pandemic workspaces, are we trading home distractions (children, pets, spouses, household obligations) for those common to the corporate office?

Much has been written about the influence of distractions on the ability to carry out work obligations, and the quality of the work that results under those conditions. In an article published in Business News Daily before the pandemic lockdown, 10 well-known causes of workplace distraction were listed. They were:

  1. Cellphones/texting
  2. The internet
  3. Gossip
  4. Social media
  5. Email
  6. Co-workers dropping by
  7. Meetings
  8. Smoke/snack breaks
  9. Noisy co-workers
  10. Sitting in a cubicle

These may be even more annoying when encountering them after months of being away from the office. Like our dismay at seeing rush-hour traffic resume after months of being able to enjoy roads largely empty of cars, we may be even more sensitive to the distractions we find when returning to the workplace. Might we now be even more sensitive to situations that destroy our concentration and make it harder to accomplish our goals in a reasonable period of time?

It is easy to find suggestions on how to overcome these distractions. Some require physically removing oneself from an environment that hampers our ability to work. Other advice includes using self-discipline to avoid responding to ambient distractions (like the ping of an incoming email) or the urge to respond to a pop-up ad on the internet when the computer is turned on.

One approach espoused by the author Cal Newport in his popular book is to establish a physical and mental state that allows for what he terms “deep work.” This is the ability to focus on a cognitively demanding task without distraction. The work may be memorizing a piece of music, figuring out how to balance the shapes and colors in an oil painting, or plotting a murder mystery, or, more conventionally, the obligations of the traditional workplace. The opposite of deep work is, not surprisingly, called shallow work and is what we do when scanning emails or scrolling through Facebook.

Recently, in association with a move to decrease the hours of the workweek, commentators have been discussing the importance of deep work. I heard the term for the first time on an NPR broadcast. The question was raised as to whether someone working 32 hours a week could accomplish the same amount of work as someone working the traditional five-day workweek. The answer was related to the ability of the employee to engage in deep work. If distractions are reduced or eliminated, it is believed that the output in four days can be as productive as produced by a five-day workweek with the usual distractions.

Engaging one’s cognitive abilities in order to focus exclusively on the work at hand requires discipline, a ritual designed to create a positive work environment, a method to eliminate distractions, sufficient sleep, and various other prompts to, in a sense, create a mental barrier between one’s cognitive activities and stimuli from the environment that inhibits concentration. One aspect of this preparation that perhaps should be added to the list of what to do (or avoid) is what to eat before the deep focus begins.

Certainly it is hard to focus when hungry or thirsty, and it is possible that the natural end of a period of intense concentration comes naturally when the body needs water or food. Moreover, it is long known that eating a large meal, which will require the blood supply diverted, to some extent, to the intestinal tract during digestion, may cause mental fatigue or even sleepiness. Focusing after a large lunch may mean trying to decide where in the workplace one can find a place to nap.

Given the current popularity of eliminating carbohydrates in order to lose weight or maintain weight loss, it seems appropriate to ask whether doing so might enhance deep focus or impair it. There is some evidence that depriving the brain of serotonin as a result of a low or carbohydrate-free diet might also decrease attentiveness. Tryptophan, the amino acid from which serotonin is made, gets into the brain only when carbohydrates are eaten. Protein inhibits this process. This question was asked in a study done several years ago that compared the effects of a low-calorie, nutritionally balanced diet with one that eliminated carbohydrate consumption. The latter would be similar to a diet that induces ketosis, that is, the state in which the brain switches to fat rather than glucose for energy.

Subjects were tested on various measures of cognition days, and then weeks, after the start of each diet regimen. The subjects who were not allowed to eat carbohydrates performed significantly worse on tests that require attentiveness and memory, the sort of functions involved in deep focus. When the subjects were allowed to eat carbohydrates again, these impairments disappeared. But there are other studies claiming that a carbohydrate-free diet that forces the brain to use fat (ketones) for energy rather than the natural energy source, glucose, can intensity focus. Many of these studies are described on blogs promoting the ketogenic diet.

Much more research should be done to clarify the different outcomes reported for diets low in carbohydrates (and thus low in serotonin). However, studies that look at the long-term effects of dietary change may be less relevant to their effects of deep focus than testing the effects of nutrients immediately after they are eaten and digested. Intensifying concentration, blocking out distraction, accessing the cognitive functions of the brain—the activities of deep focus—are meant to occur over a one- to three-hour period. It is unlikely that most people are able to maintain such a high level of concentration for much longer, or should not even try. Thus the big lunch is apt to diminish mental productivity during the afternoon, not the next day. Hunger or thirst affects concentration within an hour, or for thirst, even minutes after being noticed.

Serotonin is made within 30-60 minutes after carbohydrates are digested. If this leads to the ability to filter out distractions and concentrate, its effect will be felt within 30-60 minutes. If eating a small bag of pretzels or ¾ of a cup of Cheerios has this effect, the person striving for deep focus will notice it. And if not, that will also be noticed.

It shouldn’t be necessary to find a small cave to work in where no one will bother you. But sometimes, distractions are so pervasive, that feels like the only alternative. Eating a handful of shredded wheat squares won’t make the neighbor’s dog stop barking, or the ping of your co-workers email cease, but it may help ease yourself into a deep work mode. Just don’t focus on getting more pretzels.


Deep Work: Rules for Focused Success in a Distracted World, Hardcover, Newport C– January 1, 2016 Hachette Publisher