Long-Term Fasting

5, 7 and 10 days of fasting. Why would you want to?

By Joachim Bartoll
Classic Muscle Newsletter, August 2015 (edition #11)

Fasting for 5, 7 or even 10 days have experienced a re-birth within the health- and fitness community as of late. While the majority of people unfamiliar with its positive health effects still frowns upon the thought of going without food, more and more people is getting interested in fasting, including health care professionals.

As I wrote in my ketogenic diet series, many new treatments are initiated with at least a 5-day water fast before switching over to a standard or restricted ketogenic diet (80 to 90 percent of all calories from fat). This kind of approach is used by a few eminent and pioneering doctors and health care professionals during treatments of most cancers, neurological diseases (Alzheimer’s disease, Parkinson’s disease, autism, depression, migraines, epilepsy), chronic fatigue syndrome, polycystic ovarian syndrome (POS) and more.
This raises the obvious question – why should I care or even try a long-term fast if I’m healthy? What are the benefits?

The Health Benefits of Fasting

You may be surprised, but extremely few of us are actually really, really healthy. Most of us have some issues, and if you’re overweight you have tons of toxins stored in that body fat. So, if you can’t see your abs, you need to lose that blubber first.
With that said, what are the health benefits of fasting? Why should someone that is lean and quite healthy do an extended fast?
Since more and more researchers, health care professionals, and even doctors are turning to different approaches to fasting and the ketogenic diet, there must be something to it, right?
Yes, there certainly is. Especially if you have some kind of health problem or sickness. And even if you’re quite healthy, many of the benefits are still huge and very desirable. Let’s take a closer look.

Autophagy: Cell Renewal and Regeneration

When you have fasted for a day or two and your “immediate” energy sources, such as glycogen are depleted, your body enters what we could call a very low-energy state. At this state, your body have to get its fuel from stored body fat, from the breakdown of poorly functioning and unwanted cells and – to a very limited degree – from muscle protein. This state creates a strong demand on your cells and mitochondria to function at their highest energy efficiency. Your cells will either have to adapt to function more efficiently, or they will be “harvested” and replaced by new, stronger ones (this is called autophagy). The mitochondria can either be rescued, enhanced, or consumed through the autophagy mechanism. And when you stop eating, every cell in the body must operate at its maximal energy efficiency. That means that the mitochondria in those cells must be operational at their highest level of energetic efficiency. Otherwise, the cell will die, and the molecules of that cell will be consumed and redistributed to the rest of the body.

If you’re suffering from some kind of illness, this is good news as weak or poorly functional cells are broken down as protein and/or energy and are replaced by new highly functional ones. Even if you’re healthy, this process will enhance your physiology, make your body work better and more efficiently, and help you fight toxins as in ‘disease.’ This also means that your cell receptor sensitivity will be heightened. You will get ‘enhanced’ effects from hormones and amino acids.

Rebooting the body’s ability to detox and repair

During a long-term fast, when you begin to ‘starve’ (usually after 36 to 48 hours without food), your body tries to save energy, and one of the things it can do to save energy is to recycle a lot of the white blood cells that are not needed, especially those that may be damaged. This is part of the autophagy process. Researchers has noted that the white blood cell count goes down with prolonged fasting. Then when you re-feed, the blood cells come back. They’ve also discovered that prolonged fasting has a remarkable effect in promoting stem cell-based regeneration of the hematopoietic system. In other words, fasting not only helps to protect the integrity of your blood, but it can also regenerate the whole body by activating dormant stem cells. It’s like turning back the clock, undoing a lot of damage that have accumulated over the years.

If you get sick easily or have recurring colds, doing a prolonged fast could enhance your body and its capabilities to detoxify and help you to stay healthy.

Cancer Prevention and Cancer Treatment

As I wrote in my Ketogenic Diet Series, using prolonged fasting before beginning the restricted ketogenic diet is one of the latest methods in fighting cancer.
As part of the autophagy process, fasting can kill precancerous cells in your body – as all cells that are not functioning at optimal capacity are killed off and re-used as energy and/or building blocks for new cells. And as research has shown, cancer cells are mutated and can only use glucose and in some instances glutamine as fuel. If you cut off the supply of glucose by eliminating carbohydrates, cancer cell growth is halted as they begin to starve.

Also, deep ketosis (high concentration of ketone bodies) has shown to be poisonous to cancer cells – actually killing some of them. So, to conclude, from the research we have available today, you should be able to prevent cancer by utilizing the autophagy process from long-term fasting. And if you have some cancerous growth, you might be able to halt it and even reverse the process by doing recurrent prolonged fasts and by following a ketogenic diet in between.
The research in this field is ongoing and it’s really exciting!

Promoting longevity

Many studies that have been conducted on animals has showed that fasting has a significant impact on increasing lifespan. Obviously, no long-term studies have been conducted on humans. Yet, there is strong anecdotal evidence showing the same effects on blood markers in people, such as Insulin-like Growth Factor 1 and Growth Hormone, which highly correlate with prolonged life. Other documented benefits include improved blood sugar regulation (increased insulin sensitivity), decreased cardiovascular disease risk, and fat loss (which in itself promotes health). Also, once you start eating again you will experience a stronger anabolic response, helping you to quickly rebuild any muscle mass lost from your prolonged fasting.

Also, by taking the logical approach of the documented benefits, they all should help in increasing your chances for a longer and more healthy life.

Other Reasons for Prolonged Fasting

Although the health benefits are reason enough for most people to try a long-term fast, there are other more personal benefits as well.

Increased Will-Power

Most of us are programmed to believe that we need to eat every day in order to function and be healthy. We even shudder at the thought of doing a one-day fast. This is especially true if you’re into lifting weights and building muscle – as no food means no anabolism and increased catabolism.
Even if you understand all the benefits and are curious about trying a 5 or 7 day fast, the thought about hunger, brain fog and possible fatigue might scare you.

Well, what if we turn it around and apply the, “If I can do this, I can do anything”, mentality? For sure, only drinking water with electrolytes for 5, 7 or even 10 days might not be an easy feat to pull off. However, it’s nothing more than a challenge. A challenge with a lot of rewards. If you’re used to eating 3, 4 or even 6 meals a day, only living on electrolyte water for a week or so will be a paradigm shift for your mind. Embrace it. If you do it, a lot of other challenges will seem trivial in comparison. Not to mention how good you will feel about yourself and your strong mind and will-power once it’s accomplished. If you can go without food for 7 days, resisting a cookie during a diet will be a breeze.
Completing a long-term fast will strengthen you – not only in body and soul, but in your mind, as well.

Crappy Food De-Programming

If you really like and enjoy food, going prolonged periods without it will strengthen your appreciation for it. This is even more true if you don’t really care that much about food and your food choices. Instead of craving sugary foods, you’ll start craving nutritious healthy foods. You’ll also discover that after a fast, the smells are sharper, the tastes are stronger and the experience of eating is more rewarding.

If you’re smart about it and break your fast gently with small portions of some easy digestible fatty fish, liver, egg yolk, or even beef, you will strengthen your positive emotions towards these very nutritious foods. They will also taste better than ever before. Making it easier to stick to better food choices in the future.

Fasting is also effective for breaking addictions and re-setting eating habits and patterns. If you do a long-term fast of 7 or 10 days, it’s easier to “begin anew” once you start eating again. Laying down new behavioral patterns and habits.

The Usual Questions

Once you’re intrigued and really would like to try a prolonged fast, the first question that usually surface is, “but how can I function, how can I manage my job without eating for days?”

Is it Possible to Work and Stay Productive While Not Eating For 5, 7 or 10 Days?

Once you start a fast, you will feel really good the first and possibly a bit of the second day. This is the time-frame when your body still have access to stored glycogen. Once you run out of glycogen a metabolic shift take place. This is usually when you feel a bit crappy, especially if you’re not used to fasting or doing the occasional ketogenic diet.

A lot of people actually feel better and have more energy the first day without any food than when they eat as they normally do. This can make the transition somewhat harsher as you go from “beast mode” to feeling lethargic and foggy. Your sleep will probably suffer as well during this transition. However, as you enter ketosis and your body start to use ketones as fuel you start to feel better again. This is recognizable from the ketogenic diet, where once you’re more ‘fat adapted’ and your body has become accustomed to using ketones for fuel, you feel better than ever before and have a whole new level of mental clarity (as our brain actually prefer ketones before glucose).

So, yes. You will feel better 3 or 4 days into your fast. But it will not be exactly as it would be on a ketogenic diet, since you do not eat during a fast. There is no external fuel being provided, so your body has to rely on its own resources. Exactly how you will feel, and how your energy levels will be, is very individual. It comes down to how well your body is working (your overall current health status), how quickly it can adapt, and how readably it can tap into your body fat stores. And most importantly, how much toxins you have in your body – because, as these are being released you might feel lethargic, experience energy swings, start holding some water, and even running a slight fever. The toxic load will vary from day to day or even hour to hour.

Once you’re in deep ketosis, you will experience renewed energy and a very clear mind. Your body might still feel a bit weak from time to time, which is to be expected – and especially if your body have trouble releasing enough fatty acids from your fat stores.
Most people feel really good during day 3 to 5, and fairly good during day 6 to 7 and beyond. There will be more “dips” the longer you fast, but if you plan your fast you should be able to stay productive and manage your job just fine. For example, starting your fast on a Friday so the eventual harsh days will be during the weekend and you should feel better by Monday.

As for hunger, it usually goes away once you’re in ketosis. It will probably resurface a couple of times, but you can combat that with drinking some more water and simply wait it out. Hunger usually disappears after 15 minutes or so.

In the next part, we’ll look at preparations before starting a long-term fast and what you might need during a fast. I’ll also cover some old studies on prolonged fasting. I will also write a few stand-alone parts covering my own upcoming 7-day fast.