The Science, History, and Mindset Behind Fasting
Updated: Oct 30, 2020
We all want to live in balance. We want to live a healthy lifestyle consistently. In this day and age, it can seem impossible to know what we need to be doing to live a balanced healthy lifestyle for the long run. Without creating healthy habits (versus quick, immediately gratifying changes), we will not maintain our progress in health. But what habits should we set out to create? In this article, we’ll investigate whether or not fasting is a healthy habit we should practice on a regular basis. This article will help you have everything you need to decide if fasting is right for you.
In recent years, fasting has become one of the hottest trends. While intermittent fasting has become very popular for weight loss, there are a lot who say we should eat every couple of hours to “rev up our metabolism.” Everything in the health and wellness industry seems to contradict each other. How frustrating is that! Everyone seems to have a different opinion on what YOU should be doing. So is fasting legit or is it just some extreme fad we should stay away from?
Before we answer that question, we must look at the topic through three main lenses: historical evidence, biblical principles, and current evidence-based research. Many people set out to research a topic, but only get a partial picture because they leave one or more of these approaches out. It is only when we look through all three of these lenses that we see the full picture.
Biblical- What are the motives and mindsets behind the topic? How does it line up with biblical principles? Is this topic consistent with the Word of God and/or the proven character of God?
Historical- When and where did a topic originate? What are its results throughout history? Looking at the past reputation of a topic is crucial in determining its validity for today.
Current Research- Do current scholarly studies provide evidence to support the topic? What are the cold, hard, objective facts about the topic and its effects?
Contrary to popular belief, fasting is not a new trend. It is actually an ancient practice that can date all the way back to the beginning of mankind. “Fasting is one of the most ancient and widespread healing traditions in the world.”(4) “From earliest antiquity, peoples scattered all over the world have, for one reason or another, abstained themselves from food and drink for a shorter or longer time, as individuals or as a community. Instances collected from many books on ethnology and history of religion are abundant."(7)
The question is, why? Why have people practiced fasting for thousands of years? Many times it was for religious reasons. Other times, people viewed fasting as a crucial wellness practice. "Fasting and other dietary regimens have been used to treat epilepsy since at least 500 BC.”(1) Interestingly enough, fasting has been used for thousands of years to heal the body. The father of modern medicine, Hippocrates wrote, “To eat when you are sick, is to feed your illness.”(4) “Modern medicine” seems to have shied far away from what Hippocrates believed and practiced. He believed the body could heal itself, that many illnesses were caused by our lifestyle and diet. Using natural methods to help patients, he believed fasting and the right kinds of food could be the medicine for people to get well.
Don’t get me wrong, modern medicine does great good; it has advanced our world and saved many lives. However, if we use pills and medications as a substitute for a healthy lifestyle, we are doing ourselves an injustice. We must do everything in our power to partner with how our bodies were made, while also realizing that illness and disease occur as a result of a fallen world. It is modern medicine and healthcare that can be agents for healing in times of disease.
With information so readily available, many people’s ideas, opinions and facts upon which they base their beliefs are primarily based on current trends. The benefit when looking back at history, especially at how humans survived for thousands of years, is we get to see the lasting effects of a particular practice. It is only then that we can get the full picture.
Most of us live in a time of abundance. We have access to food whenever we want to eat, however, this has not been the case for most of human history. In ancient times, humans would have to go out and kill their food. They would eat that kill for one, maybe two days, and then they might not eat for several days until they found another meal. They were forced to fast. Their bodies would store its excess nutrients so they could survive until their next meal. Today, most people hate that we store excess food as fat, but if our bodies didn’t store fat, humans would be extinct.
The storage of nutrients as fat has kept mankind alive for thousands of years. Fat storage is a good thing, except when we store so much fat that it interferes with our body’s functions. In a time of abundance, we must keep up this lifestyle of fasting that our ancestors have practiced for thousands of years in order to live in a balance. Since our bodies are made to help us survive in between meals, we must learn to tap into these complex mechanisms and use them to our advantage, especially in a time when the survivability component is essentially wiped out due to readily available food sources.
Key Takeaway: Fasting is not a new fad. It is a proven concept that has been around for thousands of years.
First, let me put your mind at ease. Most people can be skeptical about fasting because they think of it as starvation or that their bodies are going to go into starvation mode and ruin their metabolism. I thought the same thing before I did the research. We were all taught that eating 5-7 times a day was the best way to go when it comes to losing weight and having a fast metabolism. But interestingly enough, that mindset is relatively new and has only advanced as the obesity rate has gone up.
So just to be clear, I want to differentiate between starving ourselves and fasting. “Starvation is the involuntary absence of food. It is neither deliberate nor controlled. Starving people have no idea when and where their next meal will come from. Fasting, on the other hand, is the voluntary withholding of food for spiritual, health, or other reasons. It is the difference between suicide and dying of old age.”(4) I am not advocating for extreme dieting, weight loss, or eating disorders. I am simply presenting you with the research. Later, I will help you see how to fit fasting into your healthy lifestyle.
Obesity and Diabetes
Over the last 20-30 years, obesity has become a pandemic. “At least 2.8 million people die each year as a result of being overweight or obese and the prevalence of obesity has tripled from 1975 to 2016.”(8) Diabetes can be a huge part of the obesity pandemic. The real frustration is, both diabetes and obesity are almost always preventable. Could fasting help tackle the obesity and diabetes problem we have as a country?
First, let’s talk about insulin. Insulin insensitivity is the main cause of type 2 diabetes which is closely linked to obesity. When we eat, our bodies secrete a hormone called insulin that allows those nutrients, especially sugars, to get into our cells for energy use or storage. When we are constantly eating we will have elevated levels of insulin. Our body eventually loses sensitivity to insulin causing our blood sugar levels to be out of wack. “Fasting is the most efficient and consistent strategy to decrease insulin levels.”(5) “Contrary to popular belief, all foods raise insulin.”(5) Obviously, carbs raise insulin levels much higher, but the best answer to fixing our insulin problems is to not raise insulin at all. Hence fasting. “Regular fasting, in addition to lowering insulin levels, has also been shown to improve insulin sensitivity significantly. This is the missing link in the weight loss puzzle. Most diets reduce highly insulin-secreting foods but do not address the insulin resistance issue.”(5)
There is a state that our body goes into when we eat, called the “fed state.” Once we have digested all of the food, the energy is either used or put into storage for later; our body then goes into the “fasted state” after several hours which means our body has to start using the storages for fuel. Thus, our body primarily uses our body’s fat stores when in the fasted state.
Let me give you an example. Let’s say that I made a delicious, juicy steak last night to eat for lunch today that is readily available to me in my fridge. How much sense would it make for me to go to the store, buy another steak, come back home, trim, marinate, cook and then eat the steak when I already have one readily available to me in my house? That would be pretty dumb, right? It is the same for our bodies. When we eat, our body digests and absorbs the nutrients into our blood so they can be dispersed to where our body needs them most. When nutrients are in the blood they are readily available for our body to use. Why would our bodies burn stored fat (which requires more energy to be transformed into glucose) when there is already a readily available source of energy in our blood already? It doesn’t. Our bodies use up those storages primarily when we are in the fasted state. So when you eat every couple of hours, this causes us to always have glucose readily available and therefore our bodies become efficient at storing fat, but not burning fat.
The fact is, eating 5 times a day does not solve the insulin problem. Constantly eating throughout the day and before bed sets us up to store excess energy as fat. “In fact, nighttime eating is well associated with a higher risk of obesity, as well as diabetes.”(2) “This is mostly because insulin sensitivity decreases throughout the day and into the night.”(10) Constant eating is never a good thing. We must live in a balance.
Key takeaway: Fasting can be a huge asset in helping to combat obesity and diabetes.
Digestive Health and Circadian Rhythms
The digestive system is an amazingly complex system that breaks down the food that we eat, absorbs those nutrients into the bloodstream, and gets rid of the waste. Our digestive system is made of muscle. These muscles are very resilient, but they still need rest to recover and do their job efficiently. In addition to the muscles in the digestive system needing rest, the organs that secrete the enzymes that break down our food also need a break. If we are constantly eating, our organs like the pancreas, for example, must work tirelessly to keep up with the rate we are consuming food.
Millions of people suffer from some sort of digestive system issue. This is another key benefit that fasting brings to the table: when we give our digestive system a rest period, we allow it to recover which combats symptoms consistent with irritable bowel syndrome, etc. “Fasting appears to have a positive influence on gut health.”(10) Fasting also seems to have a better effect on weight loss and other issues even better than if we were to reduce our daily calories and eat every 2 hours. “In humans, intermittent-fasting interventions ameliorate obesity, insulin resistance, dyslipidemia, hypertension, and inflammation. Intermittent fasting seems to confer health benefits to a greater extent than can be attributed just to a reduction in caloric intake.”(3) Not only is it better for your gut to not eat constantly, but it also appears that fasting actually allows for greater results.
It may seem weird to group together digestive health with circadian rhythms, the correlation surprised me too. However there is a tremendous correlation between when we eat and our daily rhythms. “Feeding signals appear to be the dominant timing cue for the rhythms of peripheral clocks, including those that control metabolic pathways. Thus, consuming energy outside the normal feeding phase (i.e., late-night eating in humans) may reset some peripheral clocks and disrupt energy balance.”(10) Translation - when we eat directly affects our metabolism and our body’s rhythms. If our body’s rhythms are off, we will not function efficiently and optimally. “Taken together, the data strongly suggests that the timing of food intake is an important determinant of human health and disease risk.”(10)
Key Takeaway: Fasting can have a huge impact on digestive health which will impact our body’s natural rhythm.
Immune support and Inflammation
Ever been told that you need to eat to keep your energy levels up when you are sick? When you really think about this idea, it doesn’t seem to line up with current evidence. When we are sick, our body is diverting most of our energy to our immune support via the sympathetic nervous system (SNS). This takes a lot of energy. When we eat, digestion requires a lot of energy via the parasympathetic nervous system (PNS). These can conflict with each other because the sympathetic nervous system can inhibit tissues that are stimulated by the parasympathetic nervous system and vice versa. For example, have you ever eaten a big meal and then exercised right after? That food seems to sit in your stomach like a rock. This is because the digestive system is stimulated by PNS and our skeletal muscles are stimulated by the SNS. The SNS takes precedence in a lot of situations because it also aids in our fight or flight response which uses skeletal muscles. When we start to use our skeletal muscles, our body takes blood flow and energy away from our digestive system and diverts it to our skeletal muscles for use. This is similar to our immune support. These systems can conflict with each other. If we eat a big meal it can take blood flow and energy away from our immune response, which is not what we want when we’re fighting an infection.
This is why Hippocrates wrote, “To eat when you are sick, is to feed your illness.”(4) Our bodies need to have all their energy focused on getting better, not digesting food. Another well-known quote from Hippocrates is “Humans, like most animals, do not eat when they become sick. For this reason, fasting has been called the ‘physician within’.”(4) This is an interesting concept to consider. There are no other animals who, when they get sick, go and eat a big meal. They tend to seclude themselves and rest. “Fasting is evolutionarily embedded within our physiology, triggering several essential cellular functions.”(2) It is our body’s natural response to fend off sickness and repair tissue. When we partner fasting with eating a diet full of nutrients, we will have a defense system that can withstand most illnesses.
Fasting is our body’s defense system. “During fasting, cells activate pathways that enhance intrinsic defenses against oxidative and metabolic stress and those that remove or repair damaged molecules.”(3) This can help with not only immune support but inflammation as well. Inflammation is often caused by stressors in our bodies; this could be the food we eat, how we move, or our stress level. “Cells respond to intermittent fasting by engaging in a coordinated adaptive stress response that leads to increased expression of antioxidant defenses, DNA repair, protein quality control, mitochondrial biogenesis and autophagy, and down-regulation of inflammation.”(3) Fasting allows our body to repair itself! It can be a great asset to us regarding our body’s defense systems.
Key Takeaway: Fasting can be a huge asset to our body’s defense mechanisms.
Performance, Metabolism, and Muscle Preservation
Fasting seems to be a great solution for weight loss and obesity, but what are its effects on our metabolism and exercise performance? Many are worried about their metabolism tanking or losing muscle mass if they start to implement fasting into their lifestyle. It is actually amazing how fasting impacts our performance and metabolism for the better. “In essence, fasting transitions the body from burning sugar to burning fat. Resting metabolism is NOT decreased but instead increased.”(5) One big reason for this change is because of hormone regulation. Fasting allows the body to balance its hormones. “Fasting actually increases HGH (Human Growth Hormone) to stimulate our metabolic processes and protect our lean body mass.”(6) This could actually help us gain lean muscle tissue and balance our often, unbalanced hormones.
Many equate fasting with starvation, which will eventually begin to burn muscle tissue for energy. This is not what happens in intermittent fasting. I love this analogy that Dr. Jason Fung gives as to the idea that our bodies will burn muscle instead of fat: “It’s as if you store firewood for a wood-burning oven. You pack lots of firewood away in your storage unit. In fact, you have so much, it is spilling out all over your house and you don’t even have enough room for all the wood you’ve stored. But when the time comes to start up the oven, you immediately chop up your sofa and throw that into the oven. Pretty stupid right? Why would we assume our body is also so stupid? The logical thing to do is to start burning the stored wood. In the case of the body, we start to burn the stored food (fat stores) instead of burning precious muscle.”(6) I love that his approach to the body is not only evidence-based but also common sense based. Our bodies are an amazing creation. One that has survived for thousands of years under extreme circumstances. The body does not ‘burn muscle’ in an effort to feed itself until all the fat stores are used.(5) This is why the body stored fat in the first place.
But what about athletic performance? First, this can depend on the type of fast you partake in. If it is a fast for several days, your performance may suffer some because you are not used to having fasted that long. But intermittent fasting is a great way to keep a balance, while still being able to perform athletically. Also, note that many attribute fatigue and a drop in performance because they eat less during the days they do intermittent fasting. This is mostly due to the lack of energy they consume.
When one first starts fasting on a regular basis, their performance may decline slightly. But as you are accustomed to exercising in the fasted state, your body becomes efficient at burning fat for energy. Hormonally, fasting can aid in energy production and muscle building?. “Over a five-day fasting period growth hormone secretion more than doubled.”(5) Growth hormone is key in muscle preservation and building. This could help immensely in the building of muscle if the fast is done at the right times. The real key here is to fast for your goals, so for most of us simply trying to maintain a healthy lifestyle of gaining lean muscle, intermittent fasting can help us do that, if we practice it on a regular basis. If you are one that has a hard time gaining weight and may even be underweight, fasting is not necessarily the way to gain the amount of body weight you need. But if you are trying to lose fat while maintaining muscle, fasting could be perfect. We will talk further about how to fast for your goals and lifestyle.
Key Takeaway: Fasting seems to have a positive effect on metabolism and muscle preservation. In addition, fasting can be a great tool to use to reach our goals.
What effect does fasting have on our cognitive abilities and focus? Well, have you ever eaten a big lunch and then tried to get some work done right after? If you like most of us, its easier to nap afterwards than be productive. Like we have talked about previously, the digestive system demands an enormous amount of blood flow and energy to break down our food. It diverts this energy away from other areas in the body in order to function efficiently. We tend to lose focus after a meal because our body diverts energy away from our brain and down to the digestive system. Fasting can enable us to have a better focus by allowing us to divert all of the blood flow we need to our brain. This is one main effector of cognitive ability that I use fasting to help me with daily.
“Dr. Geyelin was the first to document the cognitive improvement that could occur with fasting.”(1) People have been noting for many years that fasting could have a positive effect on brain function. The body’s level of focus and cognitive ability is greatly affected by what we eat. You will likely feel more energized and alert after a lunch of chicken breast and veggies rather than mac n’ cheese with a soda. The real impact of fasting is when we partner fasting with a clean diet.
Key takeaway: Fasting can have a great impact on brain function and focus.
Mindset and Practicality:
One of the most important things when making decisions that impact your health and wellness, is acknowledging the motives behind that decision. Implementing something new with the wrong motives will only set you up for failure. Additionally, it's always good to consult your doctor or a professional before embarking on any new lifestyle change.
Overcoming obstacles with fasting
One problem that people can run into as they start implementing fasting into their lifestyle is breaking the fast, it’s extremely easy to overeat. At first, this can be challenging for some people, but as you progress and get used to the routine of fasting you will overcome this challenge easily. It helps to have a plan; if you plan out exactly what you need to eat, then you will only eat that and nothing more.
Many people also tend to skip meals during fasting. Let me be clear, fasting is not just about skipping meals to eat less. It is not just skipping breakfast. It’s about getting all of the calories and nutrients you need, over a certain time period. It can be hard at first to eat all your food in a smaller window, but as you progress slowly you will become accustomed to this new routine.
Additionally, people can use fasting as an excuse to eat whatever we want, this is very easy to do even unconsciously. Partnering good nutrition with fasting is key to reaching your goals - these goals won’t be met if we are filling up on fatty, sugary foods. It is a tool we can use to partner with other healthy habits like eating well and exercising. Fasting is just about when you are eating and making sure you have time spent in the fasted state for your body to rest and reset. We have a great free resource that will help you know exactly what to get with each meal so you can partner fasting with a great diet. If you fuse two habits together, you will be unstoppable!
Fasting can also be an asset to your busy schedule. It actually frees up your time. So instead of rushing around in the morning trying to get breakfast ready, you can use that time to do other things. You can schedule your fasting around times you are busy anyway, that way you don’t have to scarf down a meal before a meeting and feel sluggish during it. Let fasting work with you as an asset that will free up your time and efforts.
The evidence can look promising. But before you start anything, you must be in the right mindset and motivated by the right things. If your only motivation is that you want to look good, your motivation will fade. If your motivations are just about you, they will be short-lived and will not produce lasting results. This is why so many people do yo-yo dieting these days, they lose their resolve because they aren’t anchored to anything bigger than themselves. Insert: use Christianity or the bible as an example of a good, lasting motivation for change.
Takeaway: Your motivation must be a long-term element that anchors you to something other than yourself.
One of my favorite things about fasting
Another main question that I always ask when looking at a diet program or the newest fad diet (which fasting is not) is what are these people trying to sell me? Almost every new fad that is created is because people want to make money. They want to sell you a plan, a bar or supplement. My favorite thing about fasting is its not a ploy that companies have supported to make a quick buck, it is a proven principle that has been around for thousands of years. Now don’t get me wrong, people will always try to sell you something that you can do while fasting, but you don’t need any of that to do it successfully.
Despite the evidence, fasting is not the end all be all. It is a tool we can use to walk in a balance. We don’t advocate diet plans, we support lifestyle changes. Fasting is not just something that you do to lose weight, it is a lifestyle. We see all throughout the Bible how there are times for fasting and times for feasting. There are times to deprive our brains of the dopamine it gets when we eat that tasty treat, and there are also times to celebrate and feast.
It’s when we are able to walk in a balance of these things that we are able to sustain a healthy lifestyle. Our other article on fasting and feasting goes deeper into this topic. The problem is, people are constantly feasting. This leads to food addiction and other diseases that are crippling and teach our bodies to require a constant supply of food. Our bodies are wonderfully made, and fasting is a great way to partner with our Creator in how He created them to function. I don’t know about you, but I don’t want to always have to rely on my next meal to get me through the next couple of hours before my blood sugar crashes. That limits us!
What does this look like for me?
There are many ways to start implementing a lifestyle of fasting. We recommend starting slow and then progressing as you become accustomed to it. The most practical way to start is intermittent fasting (IF). This will help you walk in a balance and implement fasting into your daily lifestyle. Your goals will depict your fasting time and frequency. For fat loss, fasting should be slightly longer and more frequent. If your goal is to build muscle, fasting everyday may not be the best as you start working toward that goal. Regardless of your goals, implementing some sort of fasting into your schedule can always be beneficial.
The very definition of intermittent fasting gives a picture of what this could look like. Simply put, it’s fasting, intermittently. It is not a 24 hour long fast like what most people think of; intermittent fasting consists of frequent, shorter fasts that work well with your schedule. The most common IF regiment is 16:8. This means that you will be in the fasted state for 16 hours and have 8 hours to consume all your nutrients for the day. This may seem like a lot of time, but remember that most of that time is taken up while you’re asleep. For example, if you were to stop eating dinner at 6 pm, you could then start eating at 10 am the next day and then eat until 6pm that day for your 8-hour window of eating.
The big thing to note here, is the progression. Don’t start by doing this everyday; try starting with 2-3 days per week. On the other days, try getting breakfast, lunch, and dinner without snacking, this way even on the days you aren’t fasting, you still aren’t eating constantly. Start slow and work your way up to more days of fasting each week, and with longer fasting times some days. I started slowly in the beginning and now years later I fast 5-6 days each week and on the 7th day, I will usually get breakfast with my lovely wife. If I am implementing fasting, I can still have time to celebrate and do fun things with my family and friends! Let me say it again, it’s all about balance.
What CAN I have while fasting?
A frequent question I get is, “What can I have while fasting?” There are lots of opinions on the matter but quite frankly my answer is always to cut out calories completely during your fasting times. Many people ask about having supplements or a small amount of cream in their coffee, and while those things are helpful for our health, it usually does more harm than good during intermittent fasting. Based on my own opinion and client testimonials, it can be much harder to keep up the fast when we dabble with cream and other nearly negligible calories. Now there are always exceptions to the rule and specific health needs, but for the most part, zero calories is usually my recommendation. There are a couple of items you can have while fasting that don’t affect blood sugar and have minimal effect on our digestive system: Water, black coffee, and carbonated water are okay to have as long as they do not have any other ingredients. Preferably no cream in the coffee and drinking carbonated water sparingly. There are some benefits to having bone broth as well to get your amino acids in while fasting, but when fasting for 12-16 hours, this may not be necessary. Reach out to a respected personal trainer, nutritionist or doctor in your community when implementing fasting for the first time, they are great resources!
If you need more specific help with how exactly to meet your goals, schedule a free consultation to get your questions answered or just some practical wisdom on how to get started.
You can also check out our free resource that includes the 5 cornerstones of health we teach every client. Partnering fasting with these 5 habits will have you going from Glory to Glory in your health and wellness!
Check out our other articles on fasting that will help you implement fasting right!
Fasting and Feasting | Intermittent Fasting
When you are ready to gain ground in your health this year and get on a plan that actually works, schedule a FREE breakthrough consultation and we will help you see breakthrough in your health! These are custom “breakthrough” health consultation calls for those who want clarity in how to gain ground in their health.
Wheless, J.W. (2008), History of the ketogenic diet. Epilepsia, 49: 3-5. doi:10.1111/j.1528-1167.2008.01821.x
Tello, M. (2020, February 10). Intermittent fasting: Surprising update. Retrieved June 05, 2020, from https://www.health.harvard.edu/blog/intermittent-fasting-surprising-update-2018062914156
Cabo, R. D., & Mattson, M. P. (2019). Effects of Intermittent Fasting on Health, Aging, and Disease. New England Journal of Medicine, 381(26), 2541-2551. doi:10.1056/nejmra1905136
Fung, J. (2019, July 15). Fasting - A History Part I. Retrieved June 07, 2020, from https://thefastingmethod.com/fasting-a-history-part-i/
Fung, J. (2017, October 29). Fasting Physiology - Part II. Retrieved June 07, 2020, from https://thefastingmethod.com/fasting-physiology-part-ii/
Fung, J. (2017, October 29). Fasting and Growth Hormone Physiology - Part 3. Retrieved June 07, 2020, from https://thefastingmethod.com/fasting-and-growth-hormone-physiology-part-3/
Chapter 1: Fasting In The Old Testament And Ancient Judaism: Mourning, Repentance, And Prayer In Hope For God's Presence. (n.d.). Retrieved June 09, 2020, from https://bible.org/seriespage/chapter-1-fasting-old-testament-and-ancient-judaism-mourning-repentance-and-prayer-hope-g
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Patterson1, R. (2017). Metabolic Effects of Intermittent Fasting. Retrieved June 09, 2020, from https://www.annualreviews.org/doi/10.1146/annurev-nutr-071816-064634