Carbs or fats: what is better for your brain?

Food for brain health

Along with traditional recommendations for a healthy diet, there are new approaches to eating that emerge every five years. Today, there are several popular ways of eating which contradict each other, like California vegans to Texas meat-eaters, traditional Mediterranean diet followers to straight-edgers, and Republicans to Democrats.

In the current fight, on the right corner, there is a traditional low-fat low-calorie diet as recommended by the American Dietetic Association. On the left corner is a low-carb, high-fat wholefood diet, represented by David Perlmutter and his “Grain Brain,” with Robert Atkins on his team.

A plant-based high-carbs, low-protein diet, represented by Colin Campbell and his “China Study,” with the support of all vegans of the planet, are waiting for their turn and will challenge the winner.

Improving your diet

Before we start

Please remember there are medical issues in your body only you can know about. We will be pleased if this article helps you to make the right nutritional plan, but before that, consult your common sense if your doctor is not available at the moment. This article was written by a foodie with no degrees in neuroscience or nutrition.

What our brain can use as fuel

There are only two sources of energy our body and brain can use as fuel: glucose and ketone bodies. Some scientists assumed and continue to assume that there is no other way to achieve high grades, good study results, and efficient functioning of the brain other than by consuming carbs. It is only in the last 10 years that research was conducted to find out which carbs are beneficial for the brain. However, even today studies are emerging that prove the brain functions best on sugar.


If there are still people around you who say your brain needs sugar, we hope they simply muddled up a disaccharide sucrose with the monosaccharide glucose, which our body can get from any carbohydrate (milk and broccoli included). We are sure people who prove that white sugar is good for any organ of the human body are striving to make the nation fatter, dumber, weaker, and unhealthier.

There are great low-glycemic options to get your carbs from. Cereals, grains, legumes, starchy vegetables, greens, fruits, berries, nuts, and even dairy products. Amuse your taste buds with these foods.


Another source of energy for the brain is ketone bodies, which are molecules produced in the liver from fatty acids in periods of starvation or glucose deficiency. Some studies show the consumption of fats and the low level of carbs can make you healthier, especially in cases of epilepsy (and in cases of diabetes II, some studies say). The low or no-carbs and high-fat diet proved itself effective for weight loss, and in some cases, for psychological well-being.

Brain health

What about cognitive function, memory, and the rest?

We decided to ask ourselves this question because we know the immediate effect of a chocolate bar on mood and concentration, and some of us are familiar with the confusing and stupefying effect of the no-carbs diet and exhausting workouts that leave no glycogen in the liver.

Founders of the low-carb diet know their nutrition plan is destructive for the cognitive function during the first two weeks of glucose restriction. That is why they named the first 2 weeks of adaptation a “keto-flu.” During these days, one can have a fever, feel sick, dizzy, confused, and dumb. But will these effects pass with a “flu”? Will fats affect your brain in a negative or in a positive way in the long run?

In 2009, a research study was conducted to find out how low-fat and low-carb diets affect mood and the cognitive functions of people in the long run. It turned out that in 8 weeks, the results of the cognitive tests, as well as mood assessment, showed the positive effect of both diets on both groups of low-fat and low-carb eaters. However, in 52 weeks, the positive effect of the low-fat diet was maintained, whereas for the low-carb dieters, the results returned towards baseline levels over time.

How else does food affect cognitive function?

Recent studies have shown that we can influence the neurogenesis process with what we eat as well. The process of construction of new neurons in the hippocampus is important, as it has a direct link to our mood, memory, and the speed of our reactions. And it turned out that some diets can cause a decline in neurogenesis—for example, nutrition plans high in saturated fats, and meals with an excess of sugar. Seems like our brains don’t like the overflow.

To boost the production of neurons, you can also:

  • Restrict calorie intake by 25-30% and eat less processed food.
  • Try intermittent fasting—meaning making longer pauses between meals—up to 12 or even 24 hours.
  • Eat more omega 3, vitamins A, B, E, and antioxidants.

Carbs and fats

So what should we eat to be smart?

First of all, as food-cravers, we are sorry to say that to stay healthy and smart, we should eat less. Another disappointment for those who love simple answers is both carbs (fruits, vegetables, and grains, and not white sugar, refined flour, and potato), and fats (wild fat fish, avocado, eggs, and oils, and not pork, margarine, and sausages) are necessary for your brain.

A rough carbs restriction will definitely worsen your performance in the first two weeks of the diet and is unlikely to improve it in the long run. A rough fat restriction will not influence your performance in the short term, but will definitely do harm to your brain and cognitive function in the long run.

Seems like the best way to stay smart is to eat smart. Preferring less to more, and trying to limit the consumption of white sugar and other processed foods as much as possible—and without excluding slow carbs from your diet, as research shows your brain benefits from unprocessed wholefood carbs.

Food for your brain

1:0 in favor of carbs, sorry keto-foodies

We are sorry for the followers of carbs restriction, but it seems like there is no scientifically proven evidence that the body and the brain really feel better on a high-fat low-carb diet. On the other hand, nutrition studies are in high demand for the moment and we don’t know what will nutritionists believe in within 5 years. In any case, if you’ve found the nutrition plan that is good for you, no matter how proven or unproven its benefits are, we are super glad.

To spread your nutrition beliefs, or to prove what you feel is true, you can always start your own study. You are a student now and nothing stops you from creating scientific breakthroughs. If you need any help with your research, just know that you’re always welcome at our academic writing service,

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Steven Bloom
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Steven is an IT student who constantly seeks new opportunities for self-development. He is also fond of popular culture and entertainment. Lately, Steven has started writing about the challenges he faces as a student. He finds it helpful to brainstorm when difficult tasks arise.