By Dr. Mark Atkinson, Integrative Medicine Consultant, Medical Advisor to LiveHelfi & Co-Founder The School of Biohacking
A patient of mine came to me with a low mood, afternoon energy crashes and inability to burn fat despite "doing everything right." Within three months of incorporating strategic fasting into her routine, she was sleeping better, had steady energy all day, and her inflammatory markers had significantly improved.
What changed? She gave her body permission to remember what it already knew how to do.
Fasting isn't a trending biohack—it's one of the oldest healing practices on Earth. Our ancestors didn't have 24/7 access to food. They naturally cycled between eating and not eating, and our bodies evolved sophisticated mechanisms to thrive during both states.
The problem is, most of us never give our bodies a chance to access those mechanisms. We eat from morning until night, keeping our systems locked in constant "growth mode" when sometimes what we really need is "repair mode."
Why your body actually wants to fast
Here's something that surprised me when I started incorporating fasting into my own life and my practice: when patients begin fasting correctly and consciously, they don't just lose weight or improve their blood sugar. They often tell me they feel more mentally clear, emotionally balanced, and energetically vital than they have in years.
That's not a coincidence. That's biology working as designed.
When you stop eating for 14–18 hours your body shifts into a completely different operating system. Instead of constantly processing incoming food, it turns its attention to housekeeping. Cellular repair. Fat burning. Metabolic recalibration.
The technical term for this cellular spring cleaning is autophagy, and it's probably the most underappreciated self-regulating mechanism we have. Think of it as your body's recycling programme—it breaks down damaged proteins, clears out cellular debris and basically gives your cells a fresh start.
Yoshinori Ohsumi won the Nobel Prize in 2016 for his work on autophagy, and what he discovered was remarkable: this process doesn't just clean up our cells—it may play a role in healthy ageing and in protecting against cellular damage. But here's the catch—autophagy is largely triggered by the absence of food, not its presence.
The insulin reset that changes everything
In my practice, I commonly identify insulin resistance in my patients. Insulin resistance happens when your cells stop responding effectively to insulin, forcing your body to produce more and more of it. Not just in diabetics—in people who can't lose weight, women with PCOS, men with belly fat they can't shake, anyone dealing with chronic inflammation.
Insulin isn't just about blood sugar. It's also your body's master storage hormone. When insulin is chronically elevated—which happens when we eat frequently throughout the day—your body stays locked in storage mode. Fat burning becomes harder.
Fasting gives insulin a break. A study in Cell Metabolism showed that early time-restricted eating supported insulin sensitivity in just five weeks. Not months. Weeks.
I've watched patients improve their relationship with food and their body's ability to regulate energy simply by extending their overnight fast. No extreme dieting. No complicated meal plans. Just strategic timing.
How I approach fasting with patients
Over the years, I've learned that the best fasting protocol is the one you can actually stick with. I typically start patients with something gentle—maybe a 14:10 schedule where they fast for 14 hours and eat within a 10-hour window.
For most people, this means having dinner by 7 PM and not eating again until 9 AM the next day. You're sleeping for most of those 14 hours anyway.
Some patients eventually work up to 16:8 or even 18:6 schedules. Others do well with a couple of 24-hour fasts per month. The key is finding what works for your life, your stress levels, and your individual biology.
I had one patient, a busy executive, who couldn't imagine skipping breakfast. We started with just pushing breakfast back by an hour, then gradually extending it. Six months later, he was comfortably doing 16:8 and told me it was one of the most impactful health changes he'd ever made.
The mitochondrial connection
Here's something fascinating that doesn't often get talked about: fasting doesn't just help you burn fat—it may also support your cells' ability to produce energy.
Your mitochondria, those little powerhouses in every cell, are thought to become more efficient during fasting states. They may get better at burning fat for fuel, produce less oxidative stress, and some research suggests fasting could even stimulate the creation of new mitochondria.
This is why many of my patients report feeling more energetic when they start fasting, not less. Their cells are likely becoming better at making energy.
Dr. Mark Mattson's research at Johns Hopkins showed that intermittent fasting may support brain function, neuroplasticity and cellular protection. The brain, it turns out, often runs well on ketones—the byproducts of fat burning.
When fasting isn't right
Now, let me be clear about something: fasting isn't for everyone, and it's not for every season of life.
I don't recommend it for anyone who's pregnant or breastfeeding or has a history of eating disorders. If you're on blood sugar medications, you absolutely need medical supervision.
I also see patients who are so chronically stressed that adding the stress of fasting just makes things worse. Sometimes we need to work on stress resilience, sleep quality and nervous system regulation before introducing fasting.
Your body will tell you if fasting is right for you. If it increases anxiety, disrupts sleep, or makes you feel wired and tired, it's not the right time. Listen to those signals.
Making fasting sustainable
The patients who succeed with fasting long-term are the ones who approach it as a practice, not a punishment. They support their biology instead of fighting it.
Hydration becomes crucial, especially during longer fasts. I often recommend adding high-quality electrolytes to water—sodium, magnesium, potassium—to prevent the fatigue and brain fog that can come with dehydration.
I also like to pair fasting with calming practices. HeartMath heart coherence practices, gentle yoga, meditation—anything that keeps the nervous system in a parasympathetic state. Fasting is already a mild stressor; we don't want to compound that with chronic activation of the stress response.
At LiveHelfi, we've curated some supplements that can enhance fasting without breaking it. Molecular hydrogen is being researched for its role in supporting mitochondrial function. Berberine may support the activation of AMPK, a key enzyme in energy metabolism.
One compound I find particularly interesting is spermidine, which research suggests may help support autophagy—even in the presence of food.
The breaking of the fast
How you end a fast matters as much as how you conduct it. I always tell patients to break their fast gently. Start with something easily digestible—maybe some bone broth, a small portion of healthy fats and protein, some fibre-rich vegetables.
The goal is to ease your digestive system back into action without creating inflammatory spikes or blood sugar chaos. I've seen people undermine all the benefits of a good fast by breaking it with processed foods or huge meals.
Beyond the physical
What I find most profound about fasting is how it affects people psychologically and spiritually. Taking a conscious break from constant consumption creates space—space to notice hunger versus habit, space to sit with discomfort without immediately reaching for a solution, space to reconnect with what true nourishment means.
Many patients tell me that fasting helps them realise how much of their eating is emotional or habitual rather than truly physiological. That awareness alone can be transformative.
Starting where you are
If you're curious about fasting, start gently. Maybe try a 12-hour overnight fast for a few days—dinner at 7 PM, breakfast at 7 AM. Notice how you feel. Pay attention to your energy, mood and hunger patterns.
From there, you might experiment with pushing breakfast back an hour, then two. Listen to your body. Some people thrive on longer fasts; others do better with shorter, more frequent fasting windows.
The goal isn't to follow someone else's protocol perfectly. It's to find a rhythm that enhances your health, energy, and relationship with food.
Remember: fasting isn't about deprivation. It's about giving your body the space it needs to heal, repair and remember its own innate wisdom. When approached with respect and intelligence, it can be one of the most powerful tools in your health toolkit.
Your body already knows how to fast. You just have to trust it enough to let it.
References:
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Mizushima, N., & Komatsu, M. (2011). Autophagy: Renovation of Cells and Tissues. Cell, 147(4), 728-741.
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Sutton, E. F., et al. (2018). Early Time-Restricted Feeding Improves Insulin Sensitivity. Cell Metabolism, 27(6), 1212-1221.
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Mattson, M. P., et al. (2017). Intermittent metabolic switching, neuroplasticity and brain health. Nature Reviews Neuroscience, 18(2), 63-74.
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Longo, V. D., & Panda, S. (2016). Fasting, circadian rhythms, and time-restricted feeding in healthy lifespan. Cell Metabolism, 23(6), 1048-1059.
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Michalsen, A., & Li, C. (2013). Fasting therapy for treating and preventing disease. Forschende Komplementärmedizin, 20(6), 444-453.
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Eisenberg, T. et al. (2009). Induction of autophagy by spermidine promotes longevity. Nature Cell Biology, 11(11), 1305-1314.
