Chapter 2 – The Healing Power of Fasting

In this chapter, we will be discussing the true power behind fasting and why it’s something that’s been around for centuries.

Let’s start with a miniature history lesson. Thousands of years ago, our ancestors used to hunt in order to stay alive. They went through cycles of faming and feasting; eating everything they caught and then starving until their next catch or successful hunting adventure. This form of routine was possible because, as humans, we carried a gene now known as the “Thrifty Gene”. It is hypothesized that we still have this gene till this day, allowing our feasting and faming to occur as a natural bodily function. It is hypothesized that maybe our way of eating all day goes against our own genetic code!

Supporters of the “thrifty gene” hypothesis think this is a pivotal reason why obesity and diabetes rates have skyrocketed. And that our current approach of eating all day, without ever dipping into periods of fasting, can be harmful to the body.

Moreover, before we can understand how fasting truly works in our body, we must understand our 2 energy pathways first: sugar and fat.

The first system is called the sugar-burning energy system (Glycolysis). This system gets activated when you eat something. Eating food raises your blood sugar and then signals to your cells to begin to use this sugar (glucose) as energy for the thousands of functions they perform. Sugar is the easiest way for your cells to use it for fuel.

When you stop eating or enter a fasting cycle, your blood sugar drops. The cells also sense the lack of sugar readily available and then turn to their second energy pathway to continue supporting the body’s daily functions. This is called your ketogenic system, or what some would say is your fat-burning system (Lipolysis).

This switchover in energy pathways is where the magic begins. Although every single person will fast differently, to give you a rough estimation, research shows that it can take around 8 hours for your body to enter and shift to a fat-burning system.

If you’ve never gone 8 hours without eating, chances are you’ve never experienced the healing benefits of fasting.

And on that note, the author herself has reviewed over 85 studies declaring that intermittent fasting should be used as the first line of treatment for obesity, diabetes, cardiovascular disease, neurodegenerative brain conditions, and cancer. It also stated that intermittent fasting has anti-aging effects and can help with pre- and post-surgery healing.

This meta-analysis also highlighted several key cellular healing responses that happen when we periodically flip our metabolic switch and move into our fat-burning system.

These cellular healing benefits include: increased ketones, increased mitochondrial stress resistance, increased antioxidant defenses, increased autophagy, increased DNA repair, decreased glycogen, decreased insulin, decreased mTOR, and decreased protein synthesis.

SKIP over this section if you don’t need to know the specifics of each one of these. (Click Here)

Ketones

You feel limitless when your body makes ketones.

Okay, first of all, Ketones are SO cool. The more I learned about them, the more I found myself becoming fascinated. Ketones are organic compounds that your liver produces when your blood sugar drops. Why? Because ketones are an alternative fuel source for your cells when glucose/sugar is not available. Why are they so cool? Because they also have reparative functions as well. Specifically for your nervous tissue. This is incredibly helpful because our neuroplasticity declines as we age. Neuroplasticity is your body’s ability to repair damaged nerves. They have the power to regenerate damaged neurons that carry information throughout your brain, improving your memory and ability to retain new information, as well as giving you increased focus and mental clarity.

I’m not done ranting about ketones. This energy is also much different from the energy you feel after you eat. When we operate from our sugar-burning system (glycolysis), we feel our energy go up and down. Ketone energy derived from your fat storage is much different. It is a consistent release of energy, giving you both physical and mental clarity throughout your day! Ketones will also go up to the hypothalamus of your brain, and turn off your hunger hormone (Grehlin is your hunger hormone, little extra fact). 🙂 That’s why the longer you settle into a fasting routine, the easier it gets to tolerate the absence of food. Thanks to your ketones, it takes care of your energy and feelings of hunger. It’s giving natural Ozempic. Lolll just kidding.

Lastly, this might be the most interesting fact of them all. The rise in ketones also triggers the release of a calming neurotransmitter called GABA. This neurotransmitter has an anti-anxiety effect on your brain. Personally, as someone who takes anti-anxiety medication, this really sparks my curiosity.

Autophagy Inspired Fasting!

When you fast, you put your cells into both a state of autophagy and ketosis, creating an amplified healing state that will have your body performing better than you may have ever dreamed possible. This is the magic of fasting!

If there is one cellular process that has caused so many to try fasting, it is autophagy. When there is a drop in blood sugar, your cells respond by self-repairing. Why? Because they want to become more resilient. Think of your cells like a mini version of yourself, trying to always self-improve and become a better version. They improve cellular resilience in three ways: detox, repair, and the removal of diseased cells. In 2016, a Japanese scientist, Dr. Yoshinori Ohsumi, won the Nobel Prize in physiology and medicine after revealing that in the absence of food, our cells get stronger. Ohsumi’s work was so profound that it sparked thousands of people to understand why autophagy is such a necessary healing state for the human body.

Overall, increased autophagy supports healthier, more efficient cells and is linked to better aging outcomes and reduced risk of diseases like metabolic syndrome.

Decreases glycogen and insulin stores

Glycogen is all that extra sugar that gets stored away when you’ve been eating a high-sugar diet for years. Glycogen is stored in 3 different places: your muscles, liver, and fat. The only one that is easily accessed is the glycogen in your muscles, because by doing high-intensity exercise and strength training, it can be released. But how do we target the liver and those stubborn fat stores? This is where fasting really shines.

A helpful way to think about it is like your kitchen: your fridge holds the food you use daily (readily available energy), while your freezer stores backup supplies. As long as you keep restocking the fridge, you never need to touch the freezer. But when you stop bringing in new food, like during fasting, your body is forced to rely on those stored reserves, gradually using up glycogen and then tapping into fat stores for fuel.

Did you know that your liver is one of the hardest-working organs in your body? It burns fat, breaks down hormones, and provides lots of cholesterol for your brain. Fasting is an amazing way to get the liver to release excess glycogen so that it can perform at its absolute best! Fasting gives your cells a reason to use that sugar. This is why so many fasters get lasting weight loss results: they are finally able to undo all the damage done by previous diets.

And there’s more. Fasting also forces your body to release excess insulin. As previously mentioned, insulin spikes every time you eat. Anytime you eat a high-sugar, high-carb meal, you will experience a large spike in insulin. Do this several times a day, or even for years, and you end up having insulin resistance. Just like your glycogen, when your body has excess insulin, it gets stored away in the liver and fat. And again, the more you put your body in a fasted state, the more you will force your body to excrete them to be metabolised.

Think about this for a moment. Every diet you have ever been on has started with changing the foods you were eating or limiting the amount of calories you consumed.

Fasting is based on changing when you eat and not what you eat. The simple act of compressing our food intake into smaller eating periods of 8 to 10 hours can instantly have an impact on our metabolic health!

Increases Growth Hormone Production

Your body’s growth hormones is how you stay looking young. This hormone peaks at puberty and then makes a slow decline and diminishes by the age of 30. The growth hormone performs 3 key functions: burns fat (especially around the midsection), promotes muscle growth, and promotes healthy brain growth. Decreasing your blood sugar levels and entering a phase of fasting can help you feel youthful.

Resets Dopamine Pathways

Every single time you eat, your body experiences a dopamine hit. Some people can get a rush of dopamine just thinking about food (lol me). With a regular eating schedule, having meals throughout the day, we get dopamine hits constantly. You have something called a “dopamine baseline”. When your baseline gets raised, you begin needing more dopamine to experience that rush. Just like you can be insulin resistant, you can ALSO be dopamine resistant. This is why some individuals eat more frequently than standard, because they are trying to get a normal dopamine response. We don’t just get dopamine from food; it can also come from visual or auditory triggers: the sound your phone makes when you get a message, the followers and likes on social media, etc. Not only can certain fasts help you stop the age-related decline, but they can also help restore your dopamine baseline, increasing your overall feelings of contentment.

Repairs the Immune System

Research shows performing a 72 hour fast can help your body release stem cells into the blood stream, identify worn-down white blood cells and make new ones to replace them. If you’re not familiar with stem cells, they can go to any injured body part and repair it! You can think of stem cells like the base model; they have the ability to turn into any one of these cells below. See the image.

Improves your Microbiome

Let me give you a mini “Fun-Fact” Trivia about your gut.

• You have more than 4000 different microbial species living in you, and 90% of these live in your gut.
• Evidence shows that one round of antibiotics kills 90% percent of your gut bacteria. 90 percent!
• Two of the most abundant bacterial phyla you have in your gut are Bacteroidetes and Firmicutes.
• Obesity is linked to decreased microbial diversity compared to lean individuals.
• Your microbes are responsible for weight loss, neurotransmitter production, breaking down estrogen, and so much more.
• The more microbial diversity you have, the lower your appetite will be.

Now, while this list might start to feel depressing, my last fact for you is that fasting brings back and restores your microbiome! It’s done in 4 ways: microbial diversity moves microbes away from the gut lining, improves the production of bacteria that change white fat to brown fat, and regenerates stem cells that will repair your gut lining. (brown fat is the easier fat to burn because it carries more mitochondria in its cells, having the ability to produce more heat and essentially burn off). With regular 24-hour fasts, you can help release stem cells to repair your gut, and evidence shows that longer fasts, like a five-day fast, can dramatically impact your gut bacteria (specifically the gut bacteria that are responsible for your blood pressure). It suggests that fasting could be a superior lifestyle modification over food changes to alleviate high blood pressure.

Reduces the Recurrence of Cancer

Ten years ago, The Journal of the American Medical Association released an observational study that looked at more than 2000 women between the ages of 27 and 40 who had undergone the conventional breast cancer treatment. They analysed this group for 4 years, and here’s what they found. A woman who fasted had a 64% chance less of recurrence of breast cancer! Largely because fasting created a significant decrease in hemoglobin A1c, an indicator of blood glucose levels, and C-reactive protein, an indicator of inflammation.

As someone with breast cancer in the family, changing what I can do now for prevention is at the top of my priority list.

Improving Mitochondrial Stress Resistance

This is the ability of mitochondria to keep working properly and support cell balance even when they are under stress or slightly damaged. A key concept here is mitohormesis, which means that small amounts of stress can actually be beneficial. This mild stress activates protective responses inside the cell.

In response, mitochondria turn on survival mechanisms like:

• UPRmt (mitochondrial unfolded protein response), which helps fix or manage damaged proteins
• Mitophagy, which removes and recycles damaged mitochondria

Together, these processes make mitochondria more resilient over time, helping protect against aging and diseases like metabolic syndrome.

 

Increasing Antioxidant Defenses

This means boosting the cell’s ability to neutralize reactive oxygen species (ROS)—harmful molecules that can damage proteins, DNA, and cell membranes. Through processes like mitohormesis, small amounts of stress signal the cell to produce more antioxidants (such as superoxide dismutase and glutathione). As a result, stronger antioxidant defenses can improve resilience to aging and lower the risk of diseases like metabolic syndrome.

Increases DNA Repair

DNA Repair helps the cell get better at finding and fixing damage to its DNA, which can be caused by things like reactive oxygen species (ROS) or normal metabolic stress. Through processes like mitohormesis, mild stress signals the cell to activate repair pathways such as base excision repair (BER) and nucleotide excision repair (NER). This helps maintain genetic stability, prevent mutations, and keep cells functioning properly, ultimately supporting healthier aging and reducing the risk of diseases like metabolic syndrome.

Fasting decreases mTOR

Decreased mTOR (mechanistic target of rapamycin) activity means the cell is turning down its “growth and building” signals. mTOR normally promotes processes like protein synthesis and cell growth when nutrients are abundant. When mTOR activity is lower—such as during fasting, exercise, or mild stress—the body shifts away from growth and toward maintenance and repair. This activates processes like autophagy, which helps clean out damaged cellular components and improves overall cellular efficiency. As a result, decreased mTOR is linked to better cellular health, improved stress resistance, and potentially slower aging and reduced risk of diseases like cancer and metabolic syndrome.

Fasting decreases Protein Synthesis

Decreased protein synthesis means the cell is temporarily making fewer new proteins, usually in response to low nutrients or mild stress. While that might sound negative, it actually helps the cell conserve energy and shift focus toward maintenance and repair instead of growth. This is often linked with lower mTOR activity and increased autophagy, allowing the cell to recycle damaged proteins and improve overall quality control. As a result, decreased protein synthesis can enhance cellular efficiency, reduce the buildup of faulty proteins, and support healthier aging and stress resistance.

NOW, ATTENTION ALL GYM-RATS!!!

The body isn’t “losing gains,” it’s just pausing growth to focus on repair and efficiency. During this time, processes like autophagy clean up damaged proteins and improve muscle quality. Then, when you eat again, especially protein, protein synthesis rebounds, often more efficiently.

You’re not losing muscle, you’re improving the quality of your muscle and making your body more responsive when you do eat and train. Short-term fasting does not cause meaningful muscle loss if overall protein intake and training are solid

Resistance training itself helps preserve muscle mass, even in lower-insulin or fasting states

It’s like renovating a house, you pause building to clean out the damaged stuff, then rebuild stronger.

As long as you hit protein targets and train consistently, these temporary dips in protein synthesis are part of a healthy cycle, not a setback.

The study in the Journal of Nutrition, Health & Aging in 2018 showed that obese individuals saw dramatic metabolic improvement despite eating whatever they wanted as long as they ate food within an 8-hour window, leaving 16 hours of fasting. This one study alone gives me a sense of hope that we can undo much of the metabolic damage that is causing so many of us to struggle with poor health. Changing the time period in which we eat is more important than the actual quality of the food we eat. This is great news because everyone can apply this fasting step without sacrificing their finances.

Not only are you burning energy from fat, accelerating weight loss, lowering blood pressure, cholesterol, and insulin, but the more often you can access this fat-burning state, the more repair that can happen in your body. The more you begin to consistently implement and create your lifestyle around what feels good for you, the better the results will be. You don’t need to follow the fasting regimen your neighbour is doing, either. Because what might work for them will not work for you. You get to decide what feels good and what you enjoy doing.

So now that you have a deeper understanding of why so many women love fasting, you’ll be able to appreciate it just a little more. Let’s explore the SPECIFIC benefits of different-length fasts so that you can choose the best fast for you.

SIX DIFFERENT-LENGTH FASTS

Final key notes that might be important to remember: You must go 8 hours minimum to consider it a fasting cycle, Fasting does not hurt your muscle gains! (Click here if you missed this part)

To be continued…