What Is the Grain Brain Diet? Everything You Need to Know

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Are you dealing with a foggy memory? What about neurofatigue? Are you looking for a way to improve your brain health?

If so, you’ve come to the right place.

We have a long-term solution that’s all-natural, making it a much better choice than any pill or strange quick-fix that offers instant results. We have the grain brain diet.

The grain brain diet is a nutritional diet that seeks to heal the brain and the body. For many, the guidelines laid out for this diet are exactly what they need. And the good news is that you don’t need anything special to get started.

To learn more about the grain brain diet, if it may be right for you, and how you can follow it, keep reading. We’re going to dive in right now

What Is the Grain Brain Diet? 

The grain brain diet came about with the introduction of the Grain Brain book by Dr. David Perlmutter. He developed the idea after coming to a realization about brain dysfunction and the effects of carbohydrates on the brain. Dr. Perlmutter claims that brain dysfunction is no different than heart dysfunction.

He says that the signs and symptoms of brain dysfunction build up over time as we perform certain behaviours and habits. And, there are a few other things that he discovered, too:

  • There is a positive correlation between high-carb, low-fat diets and inflammation.

  • Gluten is a dangerous substance as it is not the same as in the grains that humans used to eat.

  • Gluten sensitivity correlates to neurological dysfunction.

  • Low-carb diets are generally healthier because high levels of carbohydrates can lead to high levels of glucose, then insulin resistance.

  • Long-term exposure to high glucose from ingesting high carbohydrates can cause the body’s protein to become destroyed.

  • Unprocessed fats and cholesterol are good for you.

  • Cholesterol protects the brain.

  • There is a correlation between a larger waist size and a smaller memory centre.

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All of this information led him to develop the diet known as the grain brain diet.

Who Should Eat the Grain Brain Diet?

This diet is for all people, regardless of their age. In fact, the diet is even safe for women who plan to become pregnant or who are already pregnant.

Dr. Perlmutter suggests that people try the diet for four weeks. Along with it, he recommends following a proper fitness routine, getting enough sleep, and taking the right supplements. This will give you a great idea of how the diet can help your brain for the better.

This diet, along with the other lifestyle recommendations, will help your body shift away from relying on carbohydrates as a primary source of fuel. 

Dr. Perlmutter recommends sticking to the 90/10 rule. This means that you eat according to the guidelines of the diet 90% of the time. The other 10% of the time, you can follow your cravings and wants.

It’s essential to recognize that one slip doesn’t define your entire diet. It’s okay to restart again tomorrow as long as you keep trying.

How Does the Grain Brain Work?

Before starting the grain brain diet, there is an optional fasting period. Many of the people who opt to perform the fast do so on a Sunday so that they can start the diet on Monday.

If you decide to fast, you need to make sure that you’re avoiding food for an entire 24-hour period. You should also be avoiding any sources of caffeine during this fast. But, you should drink plenty of water. 

Throughout your time on the grain brain diet, you can return to the fasting period when desired. These fasts can last for 24 to 72 hours.

However, you should repeatedly fast only with the guidance of your physician. Dr. Perlmutter suggests that followers of the diet perform a fast four times a year, preferably during the change of the seasons.

That said, not everyone will do well fasting, even for 24 hours. If you happen to be malnourished, extremely underweight, struggle with an underlying medical condition, or have absorption issues fasting may not be suitable for you. 

If you do decide to see if the grain brain diet may benefit your brain, here are some general guidelines. 

Foods to Eat Liberally

There are many delicious and nutritious whole foods that you can eat in abundance on the diet. Make sure these are the foods you eat most often. It’s also important to make local, organic choices when you can. The fresher the ingredients, the better.

Here are some great whole-food choices that you can eat whenever you’re feeling hungry:

  • Healthy fats like coconut oil, organic grass-fed butter, cheese, avocados, olives, raw nuts, nut butter, chia seeds, and the like

  • Proteins like whole eggs, wild fish, shellfish, pasture-raised poultry or pork, and grass-fed meats, including wild game

  • Vegetables like any type of greens, bell peppers, zucchini, eggplant, and other high-fibre low-starch veggies

  • Low-sugar fruits like lemons and limes

  • Herbs, seasoning, and condiments

  • Water

  • Tea

  • Coffee

  • Almond milk



Try to avoid eating out for the first three weeks of the program. You should plan your meals throughout the week to ensure that you stick to the diet. This will help you get the dietary rules down.

When you do start eating out again, you shouldn’t be afraid to ask questions. You can get details about the ingredients used in any dish from the waiter/waitress, chef, or another staff member. Even better, create your own meal by picking and choosing different foods offered - like a large salad with lemon and olive oil (on the side) and a piece of grilled chicken or fish.

Foods to Eat in Moderation

There are some nutrient-dense foods that you can eat in small amounts, even daily, if desired. Here are some of them:

  • Vegetables like carrots and parsnips that have a moderately high starch content

  • Milk products like full-fat cow’s milk, cottage cheese, yogurt, cream, and buttermilk

  • Legumes like beans, lentils, and peas

  • Non-gluten containing grains like rice, quinoa, corn, millet, buckwheat, and the like

  • Sweeteners like natural stevia and chocolate that is at least 75% raw cocoa

  • Whole sweet fruit like berries, apples, cherries, grapes, kiwi, melon, bananas, and the like

  • Wine, preferably red wine

You should never feel shame in eating any of these foods, but you should be careful to limit yourself with these foods.

Foods to Avoid Eating

Unfortunately, there are some foods that you should avoid altogether. Like we mentioned earlier, you should follow the 90/10 rule. But, these are the foods you should avoid during the 90% of the time that you’re following the diet:

  • Foods that contain gluten

  • Processed gluten-free foods

  • Starchy vegetables like corn, potatoes, sweet potatoes, and yams

  • Non-fermented soy

  • Fruit products that have high sugar levels like fruit juices and dried fruit

  • Fried foods

  • Processed fats and oils

  • Fat-free and low-fat foods

  • Processed carbs, sugar, and starch

  • Sweeteners

Some of these foods may be difficult to avoid, but doing so while sticking to mostly whole foods, is an integral part to bolstering brain health. 

The more you focus on the foods you can consume freely, the sooner you’ll start feeling better. That means you’ll be more likely to stick to the foods that continue to serve your best health, leaving processed foods and sugars behind for good!

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The grain brain diet is an important diet when it comes to supporting brain health and reversing past damage. Just like Dr. Perlmutter suggests, you should try the diet for four weeks at first, to see if it may be right for you. From there, you can decide whether or not you want to continue.

If you’d like support with your nutrition choices, we offer free nutrition consulting. Contact us today to get started. Whether you’re starting the grain brain diet or not, we’d be happy to help.

As always, I welcome your thoughts and value your feedback. Let me know what you think by dropping me a line or commenting below.

If you haven’t already done so, please sign up to receive my newsletters for more information about brain health, neuronutrition, lifestyle tips, and nutritional advice. Of course, if I can help you or a loved one with your nutritional needs, make an appointment to see me today!


[Medical Disclaimer]

All information contained in this document is for informational purposes only. It is not intended to diagnose, treat, cure, or prevent health problems. For all serious health issues, please contact a medical or nutrition practitioner. The information provided is based on the best knowledge of the author at the time of writing, and we do not assume liability for the information, be it direct or indirect, consequential, special exemplary, or other damages. In all circumstances, it is always wise to consult your physician before changing your diet, taking supplements, or starting any exercise or health program.