What Happens When I Fast?

By on 02/05/2017

Stages of Fasting

** Please note that this is not to be considered medical advice and you should always consult your doctor before starting a fast**

Our body has sufficient fat reserves to last us for 40 days, with some even stretching as long as 10 weeks. Our body will not burn muscle as an act of natural preservation. By default, our body gets energy in this order:

Stage 1: Daily food
Glucose from our daily food consumption.

Stage 2: Glycogen from liver (Glycogenolysis)
Glycogen from our liver. Converted via Glycogenolysis; this happens when we don’t eat for four to eight hours. This lasts us for about 12 hours.

Stage 3: Glycogen from our muscles
It’s easier to get energy first from glucose, then protein, then finally fats. This is why our body tries to get energy from glycogen from our muscles after it finishes burning the glycogen from our liver. This can happen for a day or two before our body realizes that something is amiss. It then switches to ketosis.

Stage 4: Full Ketosis (Fasting)
Stage 4 occurs when our body realizes that it needs to stop wasting muscles, since it’s needed for survival. It then switches to ketosis, where it burns fat from our adipose tissues, i.e. our fat resources. This is known as the protein or muscle sparing mode because our body knows that our muscles and organs are important for the proper functioning of the body, and upon realizing no more energy is coming in, now switches to fat as the energy source. Our fat is converted into ketone which can be used for energy. This happens as long as there are no more fat reserves left — equivalent of less than 7% or 10% body fat for males and females respectively.

Since each pound of fat is 3,500 calories and our daily energy expenditure is about 1,500-2,000, that’s quite a lot of calories for the body to burn during the fast before it’ll move to the next stage (starvation). For most people, it’s around four weeks to 10 weeks (or even longer) depending on your fat percentage, body weight, body condition and so on. Girls tend to have higher fat reserves/percentage than guys, while guys tend to have a higher absolute body mass.

During water fasting, it is said that full ketosis is usually reached at approximately 48 hours for women and closer to 72 hours for men.

Fasting in Scripture


Matthew 6:16-18

Matthew 9: 14.15

Luke 18: 9-14

Prayer and Reading the Word:

1 Samuel 1:6-8, 17-18

Nehemiah 1:4

Daniel 9:3, 20

Joel 2:12

Luke 2:37

Acts 10:30

Acts 13:2

Corporate Fasting:

1 Samuel 7:5-6

Ezra 8: 21-23

Joel 2:15-16

Jonah 3: 5-10

Acts 27: 33-37

Nehemiah 9: 1-3

Physical Benefits of Fasting

1. Fasting Helps Weight Loss

Fasting can be a safe way to lose weight as many studies have shown that intermittent fasting – fasting that is controlled within a set number of hours – allows the body to burn through fat cells more effectively than just regular dieting.

Intermittent fasting allows the body to use fat as it’s primary source of energy instead of sugar. Many athletes now use fasting as means to hitting low body fat percentages for competitions.


2. Fasting Improves Insulin Sensitivity

Fasting has shown to have a positive effect on insulin sensitivity, allowing you to tolerate carbohydrates (sugar) better than if you didn’t fast. A study showed that after periods of fasting, insulin becomes more effective in telling cells to take up glucose from blood.


3. Fasting Speeds Up The Metabolism

Intermittent fasting gives your digestive system a rest, and this can energise your metabolism to burn through calories more efficiently. If your digestion is poor, this can effect your ability to metabolise food and burn fat. Intermittent fasts can regulate your digestion and promote healthy bowel function, thus improving your metabolic function.


4. Fasting Promotes Longevity

Believe it or not, the less you eat the longer you will live. Studies have shown how the lifespan of people in certain cultures increased due to their diets. However, we don’t need to live amongst a foreign community to reap the benefits of fasting. One of the primary effects of ageing is a slower metabolism, the younger your body is, the faster and more efficient your metabolism. The less you eat, the less toll it takes on your digestive system.


5. Fasting Improves Hunger

Just think about this, can you actually experience real hunger if you eat a meal every 3-4 hours? Of course you can’t. In fact, to experience the true nature of hunger, this would take anything from 12 to even 24 hours.

Fasting helps to regulate the hormones in your body so that you experience what true hunger is. We know that obese individuals do not receive the correct signals to let them know they are full due excessive eating patterns.

Think of fasting as a reset button: the longer you fast, the more your body can regulate itself to release the correct hormones, so that you can experience what real hunger is. Not to mention, when your hormones are working correctly, you get full quicker.


6. Fasting Improves Your Eating Patterns

Fasting can be a helpful practice for those who suffer with binge eating disorders, and for those who find it difficult to establish a correct eating pattern due to work and other priorities.

With intermittent fasting going all afternoon without a meal is okay and it can allow you to eat at a set time that fits your lifestyle. Also, for anyone who wants to prevent binge eating, you can establish a set time in where you allow yourself to eat your daily amount of calories in one sitting, and then not eat till the following day.


7. Fasting Improves Your Brain Function

Fasting has shown to improve brain function, because it boosts the production of a protein called brain-derived neurotrophic factor (BDNF.)

BDNF activates brain stem cells to convert into new neurons, and triggers numerous other chemicals that promote neural health. This protein also protects your brain cells from changes associated with Alzheimer’s and Parkinson’s disease.


8. Fasting Improves Your Immune System

Intermittent fasting improves the immune system because it reduces free radical damage, regulates inflammatory conditions in the body and starves off cancer cell formation.

In nature, when animals get sick they stop eating and instead focus on resting. This is a primal instinct to reduce stress on their internal system so their body can fight off infection. We humans are the only species who look for food when we are ill, even when we do not need it.


9. Fasting Contributes To Self-Enlightenment

Fasting has helped many people feel more connected to life during the practices reading, meditation, yoga and martial arts etc. With no food in the digestive system, this makes room for more energy in the body – the digestive is one of the most energy absorbing systems in the body.

Fasting for self-enlightenment, allows us to feel better both consciously and physically. With a lighter body and a clearer mind we become more aware and grateful for the things around us.


10. Fasting Helps Clear The Skin And Prevent Acne

Fasting can help clear the skin because with the body temporarily freed from digestion, it’s able to focus its regenerative energies on other systems.

Not eating anything for just one day has shown to help the body clean up the toxins and regulate the functioning of other organs of the body like liver, kidneys and other parts.