Fasting, Feeding, and Focus: Boosting your Brain


Have you ever walked into a room and felt completely stumped at your reason for being there? You may feel alone, but this experience is very common! Many people experience temporary lapses of memory and attention that may be laughed off or dismissed, but these deficits can have the potential to develop into neurological disease.

Here are statistics that will boggle your brain: The Lancet Neurology has reported that from 1990 to 2015, worldwide deaths from neurological disorders increased 37%, becoming the second leading cause of death after cardiovascular diseases. These are not from a car accident, a football game, or other unfortunate accidents. These are insidious diseases caused by damage that you can develop — or poise yourself to prevent — over many years.

Metabolism matters: your brainiest defense is a nutritional offense! Brain scientists who study nutrition to nourish healthy brain cells well into old age find that how much and how often you eat has as much of an effect on your brain health as what you eat! Having consulted the research and experts, my brain-boosting advice is to choose alternate-day intermittent fasting (with a fat-first carbs-last approach).

In short: Keep your brain humming along healthfully by becoming a mean, lean, fasting-friendly machine.  

Feed Your Focus

You may have heard the myth that your brain has to use sugar for fuel. But in less than two days, your body can run out of stored sugar to burn. If this myth were actually true, we would never have made it as humans! Think about what prehistoric people and animals had to be able to do so they could eat, and the argument seems to fall apart:

People who performed well while fasting would have been more successful at finding food (exercising while hungry). Those people survived, reproduced, and their DNA is in us today. In a modern body like yours and mine, fasting and extended exercise eats up sugar stores (glycogen strands of glucose molecules) and converts fat into ketones for energy. The people who performed well and survived were almost guaranteed to be using ketones to think. If their brains failed, we wouldn’t have brains like them today: brains that benefit from a fat-burning metabolic challenge (like exercise or fasting) balanced by periods of protein-rich food and rest.

When you eat a very high-fat diet or fast (over 12 hours for most people), your body switches from primarily burning glucose as fuel (sugar) to burning ketones as fuel (fat). Don’t worry: Your brain can use both. Your brain needs some carbohydrate to boost mood and help regulate sleep, which is one of many metabolic reasons I am sharing the good news: your weight will be safe if you choose nutrient-packed, fiber-rich, whole-food carbohydrates, like starchy vegetables or fruits, later in the day. Layered within an intermittent fasting plan, you can benefit from both forms of fuel!

Upgrade your Gray Matter

Why fasting?

Intermittent fasting has the potential to slow signs of aging while boosting physical and mental performance. Fasting drives ketosis, a physiological state that was shown to protect nerve cells (neurons) from damage in animal studies of epilepsy, Alzheimer’s, Parkinson’s, and more.


  • Fasting can be a healthy type of stress, activating your cells’ stress-management programs for a short while in the now then robustly respond to oxidative stress and inflammation later. Just like you read a book to exercise your brain, or lift a weight to exercise a muscle, you can endure metabolic challenges that exercise and improve your adaptability to stress.

Scientists now better understand that brain cells respond to short-term food restriction with an increase in autophagy, their cellular cleanup, and repair mode. Autophagy is a cellular stress-management program. Just like you cook sometimes and clean others, activating repair by turning on autophagy at regular intervals is ideal for cellular maintenance.

  • Researchers observe that fasting pushes you to produce more chemicals (like brain-derived neurotrophic factor or BDNF) that tell neurons to grow and speak with other neurons. BDNF can lower oxidative stress and inflammation, reduce your resting heart rate, and likely boost your brain power!

And don’t forget: other chemicals released while fasting, like ketones or antioxidants, also nourish, power, and protect your brain cells.

Brain Boosting Benefits

  • Grace Under Pressure. In humans, studies consistently show that chronic stress can lead to long-term challenges with anxiety and fatigue. Alternate-day fasting in mice has been shown to improve brain resilience to damage as well as reduce inflammation markers and stress-hormone levels.
  • Boosting Brain Blood Flow and Nutrition. The more blood flows to your brain, the more nutrition it receives and the better you can perform. Mouse models have shown alternate day fasting can reduce cardiovascular disease risk by improving cholesterol and triglyceride levels. For mice that have suffered a stroke, alternate-day fasting as well as limiting feeding to eight hours daily have been shown to reduce brain inflammation.
  • Improved Blood Sugar Control and Insulin levels. By supporting balanced blood sugar and improving insulin sensitivity, fasting reduces brain cell damage from glucose (glycation). High blood sugar, whether in a diabetic range or not, is correlated with brain shrinkage over several years — the one place you don’t want to lose weight! Blood sugar control in middle-age can predict elderly disease risk — so today is the day to act.
  • Improved Attention and Memory. Rodent studies suggest that intermittent fasting can protect neurons from both memory deficits and inflammation due to infection and from chemical damage to the hippocampus, a part of the brain important for learning and memory. BDNF increases calcium in neurons that may boost long-term memory formation; in the 11-month alternate-day fasting study that supports this hypothesis, fasted mice had thicker hippocampal cell layers with better learning and memory performance!

    Defend Against Degenerative Brain Diseases

    While I have stressed the importance of repairing your brain, avoiding damage in the first place is essential. The physical effects of fasting help to achieve both of these goals. Life’s stressors can damage our DNA as we age, and without adequate repair, long-term brain cell damage results, and eventually could develop into dementia and Alzheimer’s disease.

    A forward-looking study of over 2,000 women in Denmark concluded that improving insulin and blood sugar control likely helps prevent dementia. Mouse models of aging also show promise that intermittent fasting can reduce the risk of cognitive deficits and preserve function in important motor neurons, while rat models have even shown intermittent fasting can reduce the number of amyloid beta plaques and protect against developing Alzheimer’s!

    While more research in humans is ongoing and necessary, I feel it is established that using fasting as a tool to clear out your cognitive cobwebs is a brain-boosting practice that has evolved for our highest good.

    The benefits of fasting go far beyond brain health alone, but this topic is so important to share. I hope it entices you to learn more about intermittent fasting and its ability to encourage better health.

    Grab a copy of my book Glow15 to discover how easily you can set yourself up for fasting success — no starving allowed.


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