What is Fasting?

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Fasting has been around for thousands of years. Many religions, ancient and modern, have used fasting as a means of purification, penance, or spiritual enlightenment. The ancient Greeks believed it offered physical cleansing and renewal, while some primitive cultures swore by pre- war fasts to strengthen the body and the mind.

Fasting is often confused with starvation, but there’s a big difference. Starvation is the complete, extended absence of food and has serious health consequences. Fasting, on the other hand, involves redistributing energy intake for longer periods of ‘rest’ from eating than normal.

To understand the power of fasting, let’s first take a look at how it works...


Many people find the idea of fasting rather intimidating, but what they don’t realize is that we actually fast every single day to some degree. When you’re asleep, you’re fasting, hence the name ‘breakfast’, or ‘break fast’. In between meals, you’re fasting. In fact, whenever you’re not eating, you’re fasting. Here’s how it works...

At any given time, the body exists in one of two natural states — fed or fasting. The purpose of the fed state is to store energy, while the purpose of the fasting state is to burn energy.


After eating, the energy from food is broken down into glucose. When the pancreas detects elevated levels of glucose in the blood, it releases insulin.

Insulin allows the body’s cells take in and use glucose for energy. Most of us take in more energy than we need, so when the cells have enough, insulin signals to the liver to store the excess glucose as glycogen for future use.

There’s only so much space in the liver, so any further excess glucose is turned to fat and deposited around the body.


When not eating, that process is reversed. As blood glucose levels fall, the pancreas stops receiving the signal to produce insulin.

To power the body, it needs to turn to energy stores. The easiest to access is glycogen, which is released by the liver and broken down into glucose.

There is enough glycogen to last 24-36 hours. When this runs out, the body turns to its fat stores. This is how to lose weight; the body literally burns away the fat - BOOM!


The body is biologically designed to achieve balance between these two states. If constantly in a fed state, there will be an excess of blood glucose and full glycogen stores at all times, leading to increased fat storage. If always in a fasting state, then fat and glycogen stores will be depleted.

That’s where the confusion between fasting and starvation comes from. Starvation is what happens when food intake is restricted for such an extended period that energy stores are depleted and the body starts breaking down tissue like muscle to survive.

Fasting, on the other hand, is a temporary state that allows the body to burn through those energy stores, leaving room for more when returning to the fed state. It’s a perfectly natural and healthy cycle of energy intake, usage, and replenishment, as opposed to the dangerous one-way process of starvation.