What Are the Stages of Fasting? Fasting Stages Explained

by Anand Thakkar, M.D.  ~

If you have been curious about intermittent fasting, but have some fear around the idea of not eating for most of your day, then this article is for you. Without knowledge about intermittent fasting, it seems like just another restrictive diet trend, however, this is not the case. Fasting is less about starving yourself and more about scheduled eating patterns that initiate different fasting stages with different benefits.

According to research by Harvard University, intermittent fasting has shown to improve weight loss, increase life span, and improve the tolerance to various metabolic stresses in the body.

The question is, without knowledge about the different fasting stages, how do you know if you are fasting properly to get the best results?

Thankfully, we’ve created this article to teach you everything you need to know about intermittent fasting. We will cover the different fasting stages you’ll experience, so you are mentally and physically prepared to do it right.

Keep on reading to learn more.

What Is Intermittent Fasting?

Gone are the days when focusing on what foods are “good or bad”, and obsessive calorie counting was the answer to weight loss.

Intermittent fasting is an effective eating pattern that dates back since the 5th century BCE when Hippocrates mentioned that abstaining from food increased overall health and well-being.

Even before that, fasting was unintentionally practiced when hunter-gatherers endured long periods without eating due to the lack of hunting.

The process of fasting cycles between periods of eating and periods of fasting, some of the most common fasting methods are:

• The 16:8 method, which includes fasting for 16 hours and then eating for 8 hours.
• The 5:2 method, where you would eat regularly for 5 days out of the week, and then restrict your consumption for 2 days.
• The eat-stop-eat method, which is fasting a couple of full days out of the week. This looks like alternating days of eating with other complete days of fasting.

Many people find that the 16:8 method is the easiest fasting schedule to follow, and the most effective. It is important to discuss the options with your nutritional advisor before beginning fasting for the first time.

The Different Fasting Stages Explained

Understanding the physiological changes and adaptions that are happening within your body during the different fasting stages will help you during the beginning of your fasting journey.

We will review the different fasting stages and how each one has its benefits for your overall health.

Post-Absorptive Stage

During the post-absorptive stage, which is between 6-24 hours of fasting, your food has been metabolized and the glucose levels begin to drop. Initially, this causes symptoms such as dizziness, drowsiness, brain fog, and uneasiness aka “hanger”.

The body may attempt to produce glycogen, which is muscle sugar, to retrieve energy sources. Cortisol and adrenaline levels may rise initially as a stress response but will lower again soon after.

Also, the insulin levels drop and glucagon levels rise to increase insulin sensitivity which helps reduce symptoms of diabetes or developing prediabetes.

During this stage, your body uses up as much glycogen and glucose from storage as it can.

Gluconeogenesis Stage

After about 24 hours of fasting, your body is unable to support a normal blood glucose level and begins to synthesize glucose from non-carbohydrate sources such as lipids (fat) and amino acids (protein).

This process is known as gluconeogenesis. Many people, mainly bodybuilders fear that this stage causes muscle loss, which is completely untrue. During this stage, the body raises levels of human growth hormone (HGH) to keep the body in an anabolic state (muscle preserving).

This stage is known for reducing the chances of developing Alzheimer’s disease, cancer, or Parkinson’s disease because of a process called autophagy.

Autophagy is a cellular self-cleaning process where the old and damaged cells get recycled into newer, more productive cells.

Ketogenic Stage

By this stage, your body has completely run out of energy sources from glucose or glycogen, and cannot sustain itself by running off of glucogenesis. This is where it begins to dip into the body’s fat storage instead.

This process is known as ketosis or fat-adaption. The body converts fatty acids into ketone bodies to fuel the main energy source, which is your brain.

Ketone bodies are low-inflammatory, which promotes the production of “brain-derived neurotrophic factor” (BDNF). This production helps restore mental clarity by nourishing the brain with essential energy sources.

Brain-derived neurotrophic factor has also been found to induce weight-loss in lab rats by suppressing the appetite.

Final Stage

After about 72 hours into the intermittent fasting, the body is efficiently running off of its fat storage (fatty acids) and ketones for energy. The body adequately removes old cells and regenerates them into stronger, more immune-supporting cells.

Human growth hormone levels are flowing through the body to maintain muscle mass, so all your hard work in the gym is preserved. High HGH levels are also known for helping your body recover from injuries faster and speeding up the fat loss process.

Your body’s hormone levels begin to level off by this point, which assists your body reach the feeling of homeostasis.

Your cholesterol and triglyceride levels will begin to drop, supporting heart health and helping with fat loss by lowering the inflammation markers in your bloodstream.

Learn More About the Benefits Of Intermittent Fasting

There you have it! The complete rundown on the intermittent fasting stages, and how each stage has incredible benefits on improving your overall health.

Whether you are wanting to lose weight, decrease your chances of developing Alzheimer’s disease, cancer, Parkinson’s disease, or just improve your bodily functions, intermittent fasting will help you.

If you found this article helpful and want to learn more about intermittent fasting, please check out our available locations and make an appointment to find out more.

We have locations in Chicago, Hanover, and Rockford. Each location offers information on intermittent fasting, keto diet, HCG diet, nutritional counseling, food sensitivity testing, and lipotropic injections.

Your health and weight-loss journey are important to us, so contact us today to make your appointment!