Stages of Fasting

Whether you are on a ketogenic diet or you are planning your meals by adopting Intermittent Fasting schedules, any form of fasting can become tough and highly demotivating when you cannot see instant results. 

Losing weight often involves rigorous training, intense dietary restrictions, and motivation, especially when you have a long way to go. 

Fasting has been a great method of efficiently losing those couple extra pounds for centuries, however, in the current years, several technical time-restricted variations of fasting trends have emerged. 

Methods of fasting like Intermittent Fasting or circadian rhythm fasting are some time-restricted fasting methods that integrate health benefits that go beyond facilitating weight loss. 

When practicing any intense eating and fasting plan the body through a “fed-fast cycle” causing changes in one’s metabolism and hormone levels. 

Just like different stages of weight loss, the body goes through different stages of fasting that contribute significantly to one’s overall health. 

If you are someone who is on a weight loss journey and looking for a deeper insight into the biology behind losing weight, we’ve got you covered. 

Here is all you need to know about the different stages of fasting to help you become aware of the effects of fasting on your body and achieve your desired weight goals.

What is Fasting?

Fasting is a simple practice of abstaining from food in a controlled and deliberate manner for a specific period of time. 

Historically the practice of “fasting” dates back to Ancient Greece, in the 5th century, introduced by the father of Medicine himself, Hippocrates. 

According to sources, fasting or food abstinence was prescribed by Hippocrates to people with serious ailments and to treat health conditions. 

There are different types of fasting methods and techniques that allow you to achieve different health-related goals. 

What happens to the body during Fasting?

Before knowing what happens to the body when you are fasting, it is imperative to know what happens to you when you eat. 

The human body requires glucose to produce energy for sustenance, however, most cells in the body are unable to absorb glucose. 

To help solve this problem and aid in the absorption of glucose into the body, insulin comes to your aid. 

Upon eating food items that are rich in carbohydrates the body begins to break the practicals down to glucose (sugars). 

The glucose is then passed down to the bloodstream and increases the blood sugar levels in the body and alerts the pancreas to distribute insulin. 

Once the insulin has been released it attaches itself to the cells and allows sugars to enter the body to be converted into energy. 

If you have consumed an excessive amount of sugar than your body immediately requires, the glucose is then stored in the fat cells present in the body to be utilized when necessary. 

When you are fasting, your body is going through a myriad of physical and hormonal changes. 

When you abstain from food ingestion your body goes into a calorie deficit and ends up utilizing the stored energy present in the fat cells eventually leading to weight loss and providing benefits linked to weight loss.

The Four Stages of Fasting:

If you are someone who is interested in embarking on the journey of losing weight and keeping fit with the help of planning and scheduling meals through intermittent fasting, learning about the different stages of fasting may help facilitate the process. 

Ideally, the stages of fasting can be categorized into four different stages that have different contributions to one’s overall health:

  • Fed State
  • Early Fasting State
  • Fasting State
  • Long-Term Fasting State

To help you understand the changes that take place in the body during each of the stages of fasting, here is each state of fasting explained:

Stage One: The Fed State (0-3 hours)

The fed state is the very first stage of fasting which begins after a few hours of ingesting foods. 

During the Fed stage of fasting the body begins to break down the food, turns it into glucose, and begins to absorb energy. 

The blood sugar levels during the fed stage are higher than normal in conjunction with high levels of insulin secretion. 

However, the level of insulin secretion depends on the composition of the foods you have ingested. 

The levels of the hormone ghrelin also shift significantly during the fed state. Ghrelin is a hormone that helps stimulate the sensation of hunger in the body, during the fed state these hormones decrease. 

Meanwhile, the levels of the hunger-suppressant hormone leptin increase immediately after you have ingested food. 

It is important to note that during the fed-fast cycle, the fed stage establishes after you consume food.

Stage Two: The Early Fasting State (3-18 hours)

After the three-hour period of the fed stage, your body reaches the early fasting stage which often lasts for about 18 hours. 

During the second stage of fasting the insulin levels in the body begin to decrease, promoting the body to release the glycogen present in fat cells and convert it into glucose to be utilized as energy. 

Eventually, the body is unable to convert any more liver glycogen which then leads to lipolysis. 

Lipolysis is a process where triglycerides present in the fat cells are broken down into smaller molecules to be used as energy to compensate for the lack of glucose. 

The body also converts amino acids or proteins present in the muscles as a feasible source of energy. This stage is highly evident in the 16/8 intermittent fasting method where you eat between an eight-hour window and fast for the remaining 16 hours.

Stage Three: The Fasting State (18-48 hours)

The next stage or the third stage of fasting is the “fasting” state itself which starts after 18 hours of early fasting state and lasts for about 48 hours. 

During this stage, all the glycogen stored in the fat cells is completely depleted and the body begins to utilize fats and proteins as a source of energy. 

This in turn leads to the production of ketones in the body, a compound that only occurs when the body begins to convert fat cells into fuel. 

The body later reaches the point of ketosis, where the sole and primary source of energy is fats, eventually leading to exponential weight loss. 

However, how sooner or later your body reaches the point of ketosis is based on variables like food ingestion, types of foods, methods of fasting, and eating windows. 

Stage Four: The Long-Term Fasting State (48+ hours)

The last and final stage of fasting is the long-term fasting state that begins after two days of rigorous fasting. This state is also referred to as the starvation state. 

During the long-term fasting stage the levels of insulin decrease while the levels of ketone bodies gradually rise. 

The kidneys generate sugars through a process called gluconeogenesis that aids as a primary source of energy for the brain. 

The breakdown of amino acids present in the muscles also decreases to help prevent exponential muscle loss. 

Since the long-term fasting state comes with extreme food deprivation, this stage of fasting is not recommended for everyone and should only be practiced under medical supervision.