A few years ago, I went through one of the most confusing and difficult health phases of my life. I was experiencing constant brain fog, unpredictable food sensitivities, heart palpitations, and dehydration that seemed to happen for no reason. I started making mistakes at work. One day, during a severe fog episode, I accidentally drove almost 50 meters in the wrong direction. That moment terrified me.
My family doctor referred me to several specialists—cardiologists, neurologists, and allergists—yet every test came back “normal.” On paper, everything looked fine. Internally, however, it felt as though both body and brain were slowly falling apart. Focus and memory became unreliable, and even physical sensations felt difficult to trust. A deep sense of helplessness followed, until something shifted. That was the moment I realized healing had to come from taking full responsibility for my health, as I had done many times before.
That was the beginning of my deep dive into brain health. I had always been fascinated by brain function, but this was the first time that fascination became deeply personal, because my clarity, safety, and well-being depended on it. This period of exploration marked the turning point in how I approached long-term brain health.
From Confusion to Curiosity: Searching for Answers
I started studying even more about how the brain works, what affects clarity and memory, and how lifestyle choices influence cognitive function as we age. This is when I came across the fascinating connection between intermittent fasting, brain function, and a powerful protein called BDNF (brain-derived neurotrophic factor).
Interestingly, I had already been practicing a form of intermittent fasting since I had my son. I naturally ate twice a day because eating late made me uncomfortable. Without knowing it, I had been intermittently fasting for over 27 years. I always felt good doing this. However, during a very stressful period in my career, I returned to eating three meals a day and occasionally experimented with unconventional foods. Even though I generally eat very clean, it didn’t take much to trigger my sensitivities. That’s when the brain fog and palpitations intensified.
So, I returned to my natural rhythm of fasting, and the science I uncovered along the way completely changed how I understood my brain and ultimately inspired the video I recently shared.
The Conversation That Sparked This Blog
A few weeks ago, after I posted my video, “5 Ways to Boost Brain Power & Stay Emotionally Strong,” one of my longtime clients messaged me. She said the part about exercise boosting BDNF really caught her attention.
This morning, she came early to her session, full of questions.
I explained to her that BDNF is like a miracle molecule for the brain. It supports the growth of new neurons, strengthens neural connections, and plays a critical role in learning, memory, and emotional regulation (Alkurd R, 2024).
Then I mentioned something that made her eyes widen:
Intermittent fasting also increases BDNF.
If you’re curious, here’s the short video I created on that topic:
She wanted to understand more, so here’s a deeper look into what I shared with her.
How Intermittent Fasting Impacts Brain Health
When we fast, the body undergoes a metabolic shift, switching from burning glucose to burning fat for energy. This transition leads to the production of ketone bodies, which serve as an efficient fuel source for the brain.
According to a comprehensive review published in The New England Journal of Medicine, intermittent fasting triggers adaptive cellular responses that improve metabolic regulation, stress resistance, and brain health (de Cabo & Mattson, 2019). These adaptations are not accidental; they are part of our evolutionary biology.
During fasting periods, the brain activates pathways that:
- Enhance mitochondrial efficiency
- Reduce oxidative stress
- Improve synaptic plasticity
- Increase neurotrophic factors such as BDNF
Research shows that intermittent fasting stimulates a natural increase in BDNF, enhancing brain plasticity, cognitive performance, and the brain’s ability to adapt and grow (Alkurd R, 2024). It’s almost as if the brain senses a challenge and rises to meet it.
As BDNF levels increase, they help:
- Grow new brain cells
- Strengthen neural pathways
- Improve memory
- Enhance learning
- Support emotional resilience
This is remarkably similar to what happens during physical exercise. In fact, both exercise and fasting activate overlapping molecular pathways that promote brain health and neuroplasticity (Sleiman S F, 2016).
The NEJM review also highlights that intermittent fasting may protect against neurodegenerative diseases such as Alzheimer’s and Parkinson’s by improving neuronal stress resistance and reducing inflammation (de Cabo & Mattson, 2019). Additionally, higher BDNF levels are associated with reduced symptoms of anxiety and depression, something many people intuitively feel when they adopt healthier lifestyle rhythms.
For someone proactive about her health, this explanation made complete sense.
Why My Personal Experience Made the Science Even More Meaningful
When I was struggling with brain fog and unexplained symptoms, I felt disconnected from my own body. But learning about fasting, metabolic switching, and BDNF helped me finally understand what was happening beneath the surface.
Intermittent fasting gave my digestive system time to rest, improved my metabolic flexibility, and created the internal environment my brain needed to regain clarity. Over time, the palpitations faded. The fog lifted. My focus, memory, and emotional stability returned.
This personal transformation aligns with the scientific literature: when the brain is periodically challenged through fasting or exercise, it becomes more resilient, adaptable, and efficient (de Cabo & Mattson, 2019).
That is why I speak so passionately about fasting and brain health today. I have lived the difference. I now use my experience and scientific knowledge to help others better understand their bodies and regain mental clarity.
Simple Steps to Start Fasting Safely
I reassured my client that intermittent fasting does not need to be extreme or complicated. Even modest fasting windows can produce meaningful benefits.
Research suggests that fasting periods as short as 12–14 hours can initiate metabolic switching and activate brain-protective pathways(de Cabo & Mattson, 2019).
Here are simple ways to begin:
- Stop eating 2–3 hours before bedtime
Supports digestion, sleep quality, and morning energy. - Try a 12-hour overnight fast (e.g., 7 pm–7 am)
Once this feels comfortable, gently extend to 13 or 14 hours. - Hydrate well
Many people who feel “weak” while fasting are actually dehydrated. - Keep meals nutrient-dense
Focus on whole foods, adequate protein, healthy fats, and fibre. - Avoid overeating during eating windows
The goal is metabolic balance, not restriction.
She left our conversation inspired, not just to try fasting, but to continue building habits that support her brain for the long run.
Taking care of your brain is a lifelong journey. You don’t need dramatic changes, just consistent, thoughtful steps. Intermittent fasting is one of the most accessible and powerful tools we have to improve brain clarity, support emotional health, and strengthen cognitive resilience as we age.
Science confirms what many of us feel intuitively: when the brain is given time to rest, repair, and adapt, it thrives.
And as I learned from my own journey:
Your brain thrives when you give it the right environment.
“Taking care of your brain is a lifelong journey; even small, consistent steps make a big difference.”
Stay blessed,
Liset.
“For personalized intermittent fasting guidance, book a one-on-one consultation today and support lifelong brain health.”
Audio version
We can access the audio version here.