Extended Fasting 101

The idea of not eating for multiple days in a row may seem overwhelming or even extreme to some. But when done safely and with a plan, extended fasting can be a great tool to help you reset your body and your mind and help you in achieving and maintaining the path on your health journey.

But what exactly is extended fasting?

Is it safe?

Who should practice it?

Is it the best type of fasting for you?

People tend to be more familiar with intermittent fasting so questions like these are common when people start looking into extended fasting and they are great questions to explore to make sure you are finding your fasting type and what will fit your lifestyle best.

(If you haven’t yet, I do encourage you to take my Fasting Quiz to help determine your fasting type.)

But for now, we’ll discuss extended fasting to see if this is something that might be right for you.

Extended fasting—sometimes called periodic or prolonged fasting—is defined as lasting from 2 to as many as 21 or more days, and this type of fasting is less studied in humans, especially for periods longer than 4 days.⁽¹⁾

This type of prolonged fasting is not new. In fact, our ancestors who were hunters and gatherers went extended periods of time without food. It may not have fallen under the umbrella of voluntary fasting but it does highlight the fact that humans are designed to withstand periods of abstinence. On top of that, we’re markedly efficient at storing energy (e.g., body fat), and during periods of prolonged fasting and carbohydrate restriction, it’s clear that we’re wired to flip the metabolic switch to produce and use ketones, which some argue are the body’s preferred fuel source. There has been a lot of research that has suggested longer fasts are safe and beneficial for most people but this does not mean they are right for everyone as we all have our bioindividuality to keep in mind.⁽²⁾

How Does Extended Fasting Work?

Exactly how long is an extended fast? Typically it refers to a period of time over 36 hours—usually 36-72—without eating. During this time, water, electrolytes, and non-caloric beverages are allowed. (Though I do cover a bit more about this at the end of this blog regarding the fasting police so be sure to check that out.)

So what is the point of doing this to our bodies? It doesn’t exactly sound pleasant right? Well, there are actually quite a few benefits.

Benefits of Extended Fasting

• In animal studies, it has been shown that lifespan and health span are prolonged with extended fasting, and we would expect an amplification of many of the same types of benefits that we see in intermittent fasting.
• Extended fasting can promote ketogenesis, stress resistance and autophagy
• Modification, the balance of good vs. bad gut bacteria (biome), to make the tissue of the digestive tract healthy and efficient for metabolism. Healthy gut bacteria may be linked to lower levels of depression.
• Activation of stem cells which promotes multiple system regeneration
• Increased amounts of mitochondria in cells which equates to a faster metabolism
• Fasting can put you back in the driver’s seat where food no longer has to control you

Drawbacks to Prolonged Fasting

• Can be physically, mentally, and emotionally demanding
• Must be planned out including a “refeeding timeline”
• Intensity of this kind of fast is not to be done more than three or four times per year. You could actually harm yourself if you approach this method too quickly or too often.

It is always recommended that you speak with your physician before attempting any type of drastic changes to your health It also needs said that there are some people who absolutely should NOT attempt extended fasts. These groups include anyone who suffers from an eating disorder, is clinically underweight, is diabetic, has low electrolytes, suffers from dehydration or anyone under significant stress. If your “bucket” is already full because of any of these other conditions, it does not help to keep filling the bucket until it overflows. There are many instances where extended fasting can help increase the size of your “bucket” but the above cases are not typically any of them.

If you are planning to try an extended fast, I cannot stress enough the importance of community during the fasting period. You are going to need support from those around you to cope with the demands placed on you physically, mentally, and emotionally.

Is Fasting the Missing Link?

By changing the ‘when’ (which is only amplified by changing the ‘what’) you can markedly improve your health in countless ways. This is why I like to call fasting the “missing link” in most people’s diets), as I can’t think of another easier-to-implement tool with such a tremendous upside. In other words, fasting — in its various forms — is low-hanging fruit when it comes to…

• Improving body composition
• Tapping into ketosis and “keto-adaptation”
• Improving cognition and brain health
• Anti-aging/reduced biological aging
• Improved resilience/stress resistance
• Lowering inflammation in the brain, gut and body
• Elevating energy levels
• Improving circulatory health
• Regulating appetite
• Improving gut health
• Improving self-control and willpower
• And more!

Dealing with the Fasting Police

Before starting a fast, and before the “fasting police” knock on your door, please read this.

One of the top questions I get asked anytime I’m talking about fasting is “what breaks a fast?” Just like fasting itself, there is a ton of contradictory information out there.

When people discuss “breaking the fast”, they are talking about ingesting something that stops the benefits of fasting which are fat loss, autophagy and the elevating of ketones. The obvious answer about what breaks a fast is eating food. But there are many people, who some-

times find it beneficial to include some supplements in a fast such as MCT powder or bone broth. Does it momentarily pause the processes of fat loss, autophagy and the elevation of ketones? Yes, it does. But this isn’t a hard start or stop situation. If adding in a bit of bone broth allows you to go a longer period of time in your fast, then your overall benefits are going to be greater, regardless of that momentary stop.

It’s important to decide what your fasting goals are because they 100 percent matter. For me, my goals have to do with mindset and willpower. Centering my fast on going a certain amount of time without eating helps me focus and reminds me that I have control over food. It also reminds me of my strength. Having the strength and willpower to do an extended fast is extremely empowering and I can see the benefits of this in other aspects of my life afterward.

Fasting isn’t easy so I don’t think it’s terrible to include supplements if adding them in allows you to enjoy fasting more. If you’re enjoying the process, then it is likely you will fast more frequently and reap further benefits from it. Grant yourself some grace to explore what works for you and what makes you stronger and healthier. Don’t allow others’ thoughts and opinions to take away from doing something that is creating a better and stronger you.

Sources:

1. Wilhelmi de Toledo F, Grundler F, Bergouignan A, Drinda S, Michalsen A.

Safety, health improvement and well-being during a 4 to 21-day fasting period in an observational study including 1422 subjects. PLoS ONE [Internet]. 2019 [cited 2020 Nov 27];14. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6314618/

2. de Toledo, F. W., Grundler, F., Bergouignan, A., Drinda, S., & Michalsen, A. (2018). Safety, health improvement and well-being during a 4 to 21-day fasting period in an observational study including 1422 subjects. PLoS ONE, 14(1). https://doi.org/10.1371/journal.pone.0209353