top of page

What makes fasting so beneficial to our health?

With all the information out there that shows what we eat may undoubtedly be the most essential for improving our health and living longer, not eating, and specifically fasting, is now being shown to offer a great deal of benefit to our health.

Yes, not eating may actually be as important as eating for our health. But how is it possible that not eating can be beneficial to health? Many of us have always associated not eating with malnutrition and poor health.

Well, the secret comes from how the body responds to difficult situations, one of which is not having enough food to eat.

You see, our body is a very intelligent and sophisticated creation that before anything is designed to survive and preserve itself. And this need to survive is even more necessary when the very raw materials needed for survival – food – are in short supply.

Many years ago, humans experienced periods when food was scarce. They often went for long periods without food, most of which was involuntary, but which threatened their existence.

The body, being intelligent, as already mentioned, realized that it had to take extra measures to improve its chances of surviving tough times. It adapted by upregulating and turning on a number of survival systems.

1. Repair, recycling and regeneration of cells

2. Enhanced detoxification

3. Increased ability to use fat for energy.

4. More muscle growth, strength and endurance

5. Enhanced immune and healing functions.

6. Improved brain health

7. Improved circulation and heart health

So, these adaptive responses served them well at the time but also got recorded in our body’s memory so that whenever similar situations occurred, these beneficial responses were automatic and more efficient each time.

Let’s briefly look at each of these adaptive responses and how they enhance our health.

1. Repair, recycling and regeneration of cells

In times of scarcity, the body takes the time to look for damaged proteins in the tissues and cells, diseased organelles, and then recycles them (autophagy), utilizing the useful components for the repair or regeneration of tissue. This process helps to make newer cells and tissues that are healthier and keeps the body functioning well. Those cells which are beyond repair will be self-destroyed (apoptosis) and the components recycled too.

The benefits of this process are.

  • Slower aging and a more youthful appearance

  • Renewed organs that work more efficiently

  • Regeneration of joints, bones and other body structures

All the non-essential broken-down products will be removed from the body primarily through a detoxification process.

2. Enhanced detoxification

With more cellular recycling, more detoxification is needed. So, the liver upregulates detoxification processes. This enhanced detoxification won’t only help remove recycled material but everything else in the body that needs detoxification.

When you aren’t eating there is less blood and resources allocated to digestion and much more available for detoxification.

If you want to enhance effects of fasting, make sure you eat a healthy diet prior to fasting so that your body has raw materials such as antioxidants and vitamins to use for detoxification.

Because toxins are often stored in fat cells, detoxification means you have more fat cells available to be used up and burnt for energy.

3. Increased ability to use fat for energy that also supports weight loss.

The body always needs energy and so when you are fasting, the body will call on fats for energy. This means more fat breakdown especially the belly fat that is also a storehouse for toxins. Weight loss therefore becomes very easy in this fasting period.

In addition, not eating means less insulin in the blood. Insulin is produced when you eat to remove blood sugar. But insulin also makes you hungry and store fat. So lower insulin means less hunger (isn’t this interesting) as you fast but also easier fat burning.

Low insulin also means better blood sugar control, better cholesterol levels, better heart health, better reproductive health and more. We can now understand why such problems were so rare many years ago when humans regularly went prolonged periods without food.

4. More muscle growth, strength and endurance

If you haven’t heard, muscle is the currency of aging, the secret ingredient to increased metabolism and weight loss as well as very important for our strength and stability.

We also know today muscle is in short supply and fat in abundance. Not only do you lose fat when you fast, you also easily build muscle. This is largely because when you are not eating the body significantly increases the production of human growth hormone (HGH). HGH helps with

  • Building and preserving muscle

  • Burning fat

  • Improving metabolism

  • Reducing hunger

  • Anti-aging effects

  • Insulin sensitivity.

Remember that when humans had no food, they needed to upregulate survival and HGH would be needed to preserve muscle and burn fat. Imagine losing muscle when you have to search for food and be more efficient when you aren’t eating. But all the benefits that HGH brings are so beneficial to us today.

5. Enhanced immune and healing functions.

During times of fasting there are more immune boosting chemicals produced and many more anti-inflammatories and antioxidants. These help to fight off infections, reduce inflammation and oxidation and also fight off cancer cells.

The immune system had to be sharper during periods of lack of food many years ago because the body had less food and needed to be in a better position to survive any infection. Low food periods were also associated with stress and more risks being taken to get food. That would increase the likelihood of injury. Inflammation is the way your body responds to injury and heals itself. So, healing capacity would be enhanced. The body would also up regulate anti-inflammatory compounds to be on standby to quickly come and mop up anything that could harm the body in case of injury. Imagine have anti-inflammatory chemicals in your blood because you are fasting without any injury. Your body will use those chemicals to improve anywhere inflammation already exists from other causes.

The result is better gut health, better brain health, improvement in autoimmune disease, arthritis, degenerative disease and more.

6. Improved brain health.

When you aren’t eating, the brain must be more alert to find and recongise food but also to be aware of enemies since you likely won’t have as much energy to fight and defend yourself.

You can see how fasting sharpened the brain many years ago. Compounds like BDNF (brain derived neurotrophic factor) which improve memory, focus, concentration and learning as well as for nerve repair and growth were upregulated during times of fasting.

These benefits are seen after about 36 hours of fasting because at that time it becomes clear to the body that food is in short supply, and we must be alert to get more .

7. Improved circulation and brain health

Now take a moment and think about the common challenges we face today regarding our wellness – obesity, high cholesterol, high blood pressure, diabetes, arthritis, poor strength, fatigue, brain fog, memory loss, cancer, heart attacks, digestive problems, low immunity, etc.

Don’t you see how a simple practice of taking sometime away from eating can be so beneficial. I mean all you have to do is not eat.

Fasting can be so beneficial, but it also has to be done right. So let me take a moment to address three fundamental questions.

1. How long and how often should someone fast?

There are 2 types of fasting that are beneficial.

Regular intermittent fasting

This involves fasting for several hours each day and then eating within a time restricted window. Some people call this time restricted fasting or intermittent fasting. This can take on different forms. The one I like is fasting for 14 to 16 hours each day and then eating for 8 to 10 hours. But you can extend this fasting to 18 hours or even longer, shortening your eating window accordingly.

This type can be done daily. For starters you can begin at 14 hours or even 12 hours and work your way up.

Whenever you fast, try to have your last meal by 7.00pm or latest 8.00pm

Periodic longer fasting.

I also recommend that where possible do the following types of fasting.

  • A 24 hour fast once a week

  • A 36 to 48 hours once a week

  • For more experienced people 60 to 72 hours once a quarter.

Always start with shorter fasts and let your body get used to fasting.

2. Who should not fast?

Fasting is useful for anybody. However, it should be something your body can handle because by its very nature it is moderately stressful on the body. Always consult a doctor if you are not sure or if you are unwell.

The following people should avoid fasting, take shorter fasts or consult a doctor before

  • Pregnant and breastfeeding ladies

  • Children less than 16 years old

  • People with diabetes especially if not well controlled

  • If you are on multiple or chronic medication

  • If you are very ill

  • If you have serious constipation

  • People with liver or kidney disease

3. What are some common mistakes we make around fasting?

The common mistakes include.

  • Eating too much food when you are in your eating window, for those who do intermittent fasting. Too much food can undo the benefits of fasting especially in regard to burning fat and weight loss.

  • Eating too much of carbohydrate rich foods that will spike insulin and lead to more fat and glycogen storage.

  • Not being hydrated enough before and during a fast. Remember hydration is about drinking water but also ensuring that your body salts and electrolytes are balanced.

  • Starting a long fast after being on an unhealthy diet. When you are fasting the body depends on nutrients you have eaten before to make proteins, enzymes, antioxidants and other compounds that support detoxification, immune function and more. Eating well before a fast is important.

  • Not getting enough rest before and during the fast

  • Exercising too hard during a fast. Exercise is great but it can put too much strain on your body if it is so intense. This could make you struggle during a fast.

In summary, fasting is great. It has immense benefits. But it is important to listen to your body. Start with shorter fasts and grow into longer ones while making sure you are always comfortable. Prepare your body before fasts to get the best outcomes. Always stop fasting if you are unwell and consult a doctor or medical professional if you are unwell or need to be monitored during a fast.


Get this book to help you on your wellness journey.
Get a copy of Dr. Kasenene's book - Eat Your Way to Wellness.


96 views1 comment

Recent Posts

See All


faith francesca
faith francesca

Thankyou, very nice read....I had wanted to find out how the risk of getting ulcers is avoided during long periods of fasting and what if I already have ulcers.

bottom of page