What Are The Benefits Of A 36 Hour Fast?

  • Author: Katie
  • Date: October 9, 2022
  • Time to Read: 7 min.

There are a number of different takes on intermittent fasting. Intermittent fasting, combined with the keto diet can have some fantastic health, including metabolic benefits. Different benefits are achieved after different periods of fasting. Let’s find out what are the benefits of a 36 hour fast, as well as give you our top tips to get the most out of your fast.

Disclosure: Some of the links in this article may be affiliate links, meaning that we may earn a small commission if you click through using our link and make a purchase.  Please be assured that this will not cost you any extra money. Also, please be assured that any of the products we recommend, we either use personally or have been recommended by trusted friends who currently use them.

Intermittent fasting has become increasingly popular. As more studies are done on the health benefits, and more celebrities are making IF mainstream, more people are wanting to give it a go.

In this article, we will take you through the different types of fasting that are available and how to get started on these. We will also take you through the many health benefits of a 36 hour fast as well as give you our top tips on fasting.

Check out our guide for more on intermittent fasting key terms.

Intermittent Fasting Timetable

Below we will take you through the intermittent fasting timetable, this is a rough guide as to at what time each metabolic process kicks in.

Another thing that you should be aware of is that this timeline represents the process of intermittent fasting from a starting point of ‘normal’, i.e. non-keto eating.

If you are starting a 36 hour fast from a point of already being in ketosis, this timeline will be accelerated.

At the time of writing, there have been no studies completed on the impact of keto and the intermittent fasting metabolic timeline.

However, it is likely that as a minimum that if you are already in ketosis (and have been for a period of weeks) it is likely that undergoing a 36 hours fast is going to start at around the 24 hour mark.

This will mean that you will spend longer in the state of autophagy than people starting a fast from a carb eating diet.

Stages of Intermittent Fasting

4-6 Hours  –  Blood Glucose Drops

This is all part of the process of getting into ketosis. The body will burn through any glycogen stores in the body.

10-12 Hours  –  Liver Glycogen Used

Glycogen is mainly stored in the liver and the muscles. It provides the body with a source of energy when blood glucose levels decrease.

12-14 Hours  –  Rise In Ketones

Insulin helps fuel the body’s cells by converting sugar into energy. When there isn’t enough insulin, ketones build up.

18-20 Hours  –  Fat Oxidation Increases

Fat oxidation refers to breaking down fats into energy. 

22-24 Hours  –  Liver Glycogen Depletion

Glycogen depletion happens when the body runs out of glycogen stores because of lack of food (due to fasting OR eating reduced carbs), or due to intense exercise which has used up the body’s glycogen supplies.

24 Hours  –  Gluconeogenesis Progresses

Gluconeogenesis is the process by which glucose is synthesized from non-carbohydrate metabolites. In simple terms, this is the process when the body creates carbohydrates (glucose) from fat and protein. 

24-36 Hours  –  Growth Hormone (HGH) Spike

Several studies have shown that fasting leads to a major increase in HGH (human growth hormone) levels.

HGH is responsible for maintaining, building, and repairing healthy tissues in the brain, as it helps regulate body composition, fluid balance, muscle, and bone development.

36-48 Hours  –  Autophagy Increases

Autophagy is a natural process by which our bodies clean out damaged cells so that new, healthier ones can be regenerated. Studies have also shown that autograph plays a vital role in improving brain function.

48-72 Hours  –  Ketosis Deepens

When your body doesn’t have any carbohydrates available to use for energy, it goes into a state called ketosis. Instead, it burns fats and produces ketones, which it uses for energy.

This has already started between 12 and 14 hours, and between 48 and 72 hours, this process intensifies with more ketones being produced. 

What Are The Benefits Of A 36 Hour Fast

There are a whole host of benefits of fasting, we have listed some of the main benefits of a 36 hour fast.

Fat Loss

As your body transitions to using fat for fuel (known as becoming fat adapted), your body will be burning through your fat supplies. This reduces the amount of fat in the body and can be measured by tracking your fat percentage.

Muscle Definition

This links in with fat loss above. The more fat you lose from around your muscles, the more you will see the definition of your muscles. This is why extended fasting is often used by bodybuilders, before a competition.

Deeper Ketosis

Ketosis is when your body uses fat for energy instead of glucose. Entering into ketosis is what everybody eating a keto diet is seeking to achieve. Deeper ketosis brings with it its own list of health benefits, allowing the body to repair and regrow.

Increased Autophagy

Autophagy is a process where cells degrade themselves through lysosomes. This process helps the cell recycle damaged proteins and organelles. The process of autophagy is essential for cellular homeostasis and survival.

Reducing Inflammation

Fasting helps reduce inflammation because it causes the body to release hormones such as glucagon, which reduces blood sugar levels. This leads to lower insulin levels, which decreases inflammation.

Resets Gut Microbiome

By fasting for 24 hours, or longer, our bodies begin to detoxify and cleanse themselves from toxins. When our gut microbiome is in balance, our guts will help us digest food easier, leading to less bloating and discomfort.

Mental Clarity

After your body cleanses itself of toxins, your mind has access to a cleaner bloodstream, which results in clearer thoughts, faster processing, better memory, and sharper senses as a whole.

Hormonal Balance

Extended fasting gives the body the time it needs to reset its hormonal balance. This can help with a whole host of issues such as mood, and skin condition.

Weigh Loss

It is unsurprising that one of the outcomes of extended fasting for a period of time will lead to weight loss.

A study completed in 2019 concluded that people who underwent several periods of fasting over a year period lost significantly more weight than those that did not.

How To Get Started On a 36 Horus Fast

Going from zero to a 36 hours fast is a big step. Although we do not want to discourage you from trying too fast of this length, we would suggest that before you jump into a 36 hour fast you follow all of our steps below.

SETP 1: Got to grips with keto

STEP 2: Is fat-adapted

STEP 3: Is accustomed to intermittent fasting 

STEP 4: Has successfully completed a couple of weeks at 20:4

STEP 5: Has completed a few rounds on One Meal A Day (OMAD)

STEP 6: Has successfully completed Alternate Day Fasting (ADF).

It is only at this point that I would recommend that somebody attempt a 36 hour fast.  

After completing a 36 hour fast, or several of them, you may want to have a go at extended fasting.

Check out our ultimate guide for getting started on intermittent fasting for more information on these stages.

During Your 36 Hour Fast

What Can You Drink During Your Fasting Window?

In short, you can drink anything that does not impact your insulin resistance. In reality, this is very few drinks, and you are limited to;

  • Black coffee
  • Black tea
  • White tea
  • Green tea
  • Still Water
  • Sparkling water
  • Mineral water

Check out our article if you want to find out more on what to drink when intermittent fasting.

It is essential that you remain hydrated at all times, not just when you are fasting.

You cannot eat anything during your fast.  

How Not To Ruin The Health Benefits Of Your 36 Hour Fast

So as not to undo all of the hard work and health benefits of your 36 hour fast, plan your exit strategy before you even begin your fast.

After not eating for as long as 36 hours, you will need to ‘warm up’ your gut before returning to eating solid foods. For keto eaters, we would recommend a mug of bone broth.

Check out our article on what to eat to break a fast for the ultimate guide on this.

What A 36 Hour Fast is Not For

Here we will look at what/who a 36 hour fast is not for, or who should be particularly careful on deciding whether to fast.

Medical Conditions

If you are already on medication or have any diagnosed, or undiagnosed health conditions, please do not undertake a fast.

Consult with a medical professional, or registered healthcare provider before undertaking intermittent fasting on keto, or even if you are not combining intermittent fasting with keto.

Intermittent fasting is not particularly not advised for those with amenia.

Out Eat A Bad Diet

Intermittent fasting is not designed to be the solution to eating a bad diet.

The idea is not that you go out on a weekend, binge eat junk food, drink to excess, and then fast at the beginning of the week to compensate.

The reality is that without eating good quality, nutrient-rich foods before a diet, your body will not have what it needs in order to keep you going through your fast.

Fasting following binge eating/ drinking will be extremely difficult to undertake a fast as your body is not set up with the correct nutrition in order to be able to undertake a fast and reap all of the health benefits.

Final Thoughts

What are the benefits of A 36 hour fast? The benefits are extensive and include, but are not limited to fat loss, muscle definition, improved immune system, improved insulin sensitivity,  improved heart health, deeper ketosis, increased ketone levels, reduced inflammation, increased autograph, and improved gut biome, and improved sleep, and mental clarity. What’s stopping you?

Leave a Reply

Your email address will not be published. Required fields are marked *

Skip to content