Have you ever felt listless and unmotivated after a big meal (like Thanksgiving), or tried to slog your way through a meeting right after lunch? Then you know, in a way, that what you eat can profoundly affect your productivity and focus.
But it goes much deeper than just feeling sleepy after a big meal. The food you eat provides the raw materials to keep your body going, including your brain and nervous system. Surprisingly enough, your digestive system and your brain are intricately connected.
Here’s how what you eat affects your brain, including what we know about the role of diet in stress, productivity and focus, based on my experience as a registered dietitian–along with some helpful hints from a gut health expert about ways you can make small changes to your diet to boost your brain function.
How diet affects your brain
What you eat can have a huge impact on your day-to-day productivity and focus, as well as your stress levels–be it due to meal composition, nutrient content, the effects of different ingredients and constituents of food, or your gut health. Here are some of the diet factors that may have the biggest impact on your brain health.
Macronutrients literally means “large nutrients.” These are the nutrients that make up the vast majority of our diets: protein, carbs, and fat. These are also the only nutrients that provide calories, with the exception of alcohol—and we’re all already pretty aware of the effects alcohol has on the brain. Here’s a quick rundown of each:
- Protein: Protein provides the building blocks the body needs to create new proteins, including muscles and other body tissues. Good sources of protein include meat, fish, eggs, beans, nuts, and seeds.
- Carbs: Carbs, short for carbohydrates, provide energy in the form of natural sugars. Complex carbs that contain fiber, like vegetables, fruits, beans, and whole grains, are your best choices.
- Fat: Fat provides the most calories, and—although it’s gotten a bad rap over the years—is absolutely vital for essential body (and brain) function. Fat is found in meat and eggs, butter, oil, nuts, and seeds.
Eating a proper balance of macronutrients is key to make sure that you have enough energy to get through the day, and that you actually feel well enough to focus on what you need to do.
Too little protein and fat, and you’ll find yourself with up and down blood sugar levels that can leave you feeling drained and “hangry” until your next meal.
Too few carbs, and you may find yourself feeling sluggish all day, as carbs provide quick-acting energy. One caveat to this is the low-carb keto diet, which we’ll discuss in more detail later.
As a general rule of thumb, most people should aim to get about 50% of their calories from carbs, 30% from fat, and 20% from protein.
Micronutrients, on the other hand, are “small nutrients.” These are the vitamins and minerals in the food that we eat. Vitamins and minerals play hundreds, if not thousands, of roles in the body, and eating a varied, healthy diet is the best way to make sure you’re getting enough of them.
Some micronutrients of note when it comes to productivity and stress include the B-vitamins, vitamin D, and magnesium. Eating a balanced, varied diet and spending time outside in the sun can help ensure that you’re getting enough of these nutrients.
Ingredients and biological components of food
Finally, the other ingredients or biological components of food may also affect your productivity and focus.
Antioxidants, while not considered essential like vitamins and minerals, are found in fruits and vegetables. These plant compounds help to ward off the accumulation of something called free radicals, which are harmful, unstable compounds that can cause inflammation and damage your cells when they build up in high amounts—leading to chronic disease and stress. Free radical damage is also known as oxidative stress, which is where we get the name “antioxidant” from.
Unfortunately, food intolerances can also be a huge impediment to productivity. If you’re dealing with persistent heartburn, bloating, constipation, or diarrhea due to a food intolerance, this can really put a damper on your ability to get things done and provide a constant source of stress.
Some common intolerances include intolerances toward gluten, dairy, and nightshade vegetables like tomatoes. However, food intolerances are a very individual thing. If you suspect a food intolerance, you should consult a registered dietitian or doctor who specializes in digestive health for more help.
The gut-brain axis
Another key factor to consider is the “gut-brain axis,” or the line of communication between your digestive system and your brain.
According to Caitlin Beale, MS, RDN, a private practice dietitian specializing in gut health, the gut-brain axis is “the bidirectional communication that occurs between the gut and our central nervous system.” She continues, “If you’ve ever felt butterflies in your stomach before public speaking or something that makes you nervous, then you’ve experienced the gut-brain communication.”
The billions of bacteria in the gut may influence your brain and central nervous system positively or negatively, depending on the ratios of healthy and unhealthy bacteria colonizing your digestive system.
“The bacteria in our gut can both create and influence the neurotransmitters in our brain, which in turn can have effects on brain health and mood,” Beale explains.
Alterations in gut health have also been linked to conditions such as depression and anxiety.
“The gut also produces the majority of serotonin, which is a ‘feel-good’ neurotransmitter that impacts mood, as well as digestion,” says Beale. She goes on to explain that the bacteria in the gut can also produce short-chain fatty acids (SCFAs) as a result of fiber fermentation, which can positively influence memory and learning.
“People with an unhealthy gut,” she explains, “can experience brain fog and fatigue–possibly related to improper digestion or absorption of nutrients, inflammation, or byproducts of unhealthy bacteria—leading to decreases in focus and productivity.”
Healthy changes to boost your brain power
According to Beale, there are four diet changes you can make to support a healthy gut. These four factors are also backed by scientific research into the effects of nutrition on cognitive function.
Include fermented foods and probiotics
Fermented foods–like yogurt, kombucha, and kimchi–are rich natural sources of healthy bacteria that can populate your gut, known as probiotics. Including these foods in your diet can help to rebalance the ratios of bacteria in your gut, promoting the proliferation of healthy bacteria and helping to crowd out the unhealthy bacteria that may be running rampant and causing digestive issues.
Remember, gut bacteria help to both create and influence neurotransmitters, produce serotonin, and create SCFAs which can influence the brain. It is vitally important for your overall wellness that you have a healthy balance of gut bacteria.
Alternatively, you can take a probiotic supplement. It’s best to choose a refrigerated one, as this helps ensure that the bacteria in the supplement survive long enough to make it to your digestive tract.
Eat an anti-inflammatory diet
Inflammation is your body’s immune response to injury or illness, but when it becomes chronic it can be an issue. Chronic inflammation is linked to the development of type 2 diabetes and heart disease, as well as brain disorders like Alzheimer’s disease.
Inflammation and oxidative damage from free radicals often go hand-in-hand, so an anti-inflammatory diet should address both inflammation and free radical activity.
The diet should include anti-inflammatory omega-3 fats from foods like fatty fish, chia seeds, or flax seeds. It should also be rich in a variety of fruits and vegetables, which provide antioxidants.
Additionally, it should limit or exclude inflammatory foods. Unfortunately, in today’s food climate, many foods promote inflammation. Here are some pro-inflammatory foods that you should limit:
- Added sugars, like those in sodas, snack cakes, cereals, desserts, etc.
- Highly processed foods like frozen and boxed meals and snacks
- Fast food
- Seed oils like soybean oil, corn oil, and vegetable oil
Even if you can’t avoid all of these foods, try your best to limit added sugar and seed oils. Sugar is profoundly pro-inflammatory, and recent research suggests that it may have an even stronger causal link to heart disease than saturated fat and cholesterol.
Additionally, seed oils are full of omega-6 fats, which can promote inflammation if you’re not also consuming enough anti-inflammatory omega-3 fats. Try replacing them with olive oil, avocado oil, and coconut oil.
Increase your fiber intake
Fiber is a prebiotic, or a food source for the healthy bacteria in your gut. When these bacteria break down fiber, SFCAs are produced–which can help promote memory and learning via the gut-brain axis.
Fiber is found in fruits, vegetables, nuts, seeds, beans, and whole grains. Best of all, when you increase your fiber intake from whole foods, you’ll naturally increase your antioxidant intake. Fiber can also help promote regularity if you suffer from constipation.
Eat plenty of healthy fat
Although fat was once considered a dietary villain, it’s no longer something to be feared. The supposed link between dietary fat and heart disease was a result of flawed research, and emerging evidence suggests that dietary fat and cholesterol play only a small role in heart disease, if any. Besides, fat is vital for healthy brain functioning.
The myelin sheath, or the protective barrier around your nerves, is made of cholesterol. And cholesterol is also a key component of many hormones, which are the chemical messengers that help your body function properly.
In fact, dietary cholesterol–found in animal foods–can help to heal damaged myelin sheaths in people with multiple sclerosis, a condition of nerve demyelination.
Some healthy sources of fat to include in your diet are wild-caught fatty fish, nuts and seeds, avocados, grass-fed beef, pastured eggs, butter, full-fat dairy, avocado oil, coconut oil and olive oil.
The keto diet
One final consideration, especially for you productivity hackers, is the keto diet. This low-carb, high-fat diet is extremely effective at treating epilepsy in certain individuals, because of its profound effects on the brain and nervous system.
In recent years, it’s been widely used as a weight loss diet. However, more and more research suggests that the keto diet may super-charge your brain function. It may help prevent or treat depression, Alzheimer’s disease, and migraines.
On keto, you shift to burning fat as your primary fuel instead of carbs. This allows you to easily access your body fat stores and burn them for energy, which helps stabilize your blood sugars and keep you from getting hangry, irritable, and distracted. Anecdotally, people report more energy throughout the day, fewer “slumps,” and increased productivity when they’re burning fat instead of carbs.
Now, the keto diet is a big adjustment–requiring you to slash most carbs from your diet and significantly increase your fat intake, but if you’re up for some self-experimentation then it’s something to consider. Just remember that the science surrounding keto diets and the brain is still evolving, and there’s no guarantee that keto will improve your productivity.
If you do try keto, remember to keep it gut-healthy by including healthy fat sources, fermented foods, and plenty of fiber, and avoiding highly processed, proinflammatory foods.
What you eat can have a significant impact on your brain function, productivity, and stress levels as a result of the gut-brain axis, the two-way communication between your brain and your digestive system.
Some ways to improve your productivity and brain function through diet include eating fermented foods or taking a probiotic, eating an anti-inflammatory diet, increasing your fiber intake, and getting adequate amounts of healthy fat. The keto diet is also a promising option that may boost your productivity and focus, although it is very restrictive.
“The health of our gut is essential for overall wellness,” Beale concludes, “including our brain health.”