Eating is nourishing oneself from the outside. Fasting is nourishing oneself from the inside. Three phenomena are then at work: a liver detoxification phenomenon, a cellular cleansing, and a fuel change.

We are genetically programmed to fast: a healthy person of normal weight can fast for 40 days. The world record is held by Angus Barbieri, who fasted under medical supervision for 382 days. His weight dropped from 207 to 82 kilos.

How it works?

1- Liver Detoxification

Freed from its digestive work, the liver will be able to carry out a deep detoxification that it cannot normally carry out.

In summary:

Phase 1: The liver transforms fat-soluble toxins (stored in fats) into intermediate substances.
Phase 2: It neutralizes these substances by making them soluble in water so that they can be eliminated via urine or bile.

Benefits during a fast:

Elimination of accumulated toxins such as pesticides and food additives, drug and medication residues stored in tissues, environmental pollutants such as heavy metals, solvents and plasticizers (phthalates or BPA), alcohol and its degradation by-products. But also endogenous toxins such as digestive waste (lactic acid, ammonia), excess hormones and free radicals linked to oxidative stress.
Reduction of the overall toxic load improving optimal organ functioning
Improved metabolism and cellular functioning.
Visible effects: clearer complexion, smoother digestion, increased energy.

Fasting therefore acts as a real “reset” of the liver.

DID YOU KNOW?

A study conducted by the Buchinger Wilhelmi Clinic examined the impact of a 10-day fast on the excretion of heavy metals and glyphosate in 109 participants. The results showed a significant decrease in urinary concentrations of arsenic (72% reduction) and nickel (15% reduction) after the fast. Additionally, a hair analysis conducted on 22 subjects 10 weeks after the fast revealed a 30% decrease in lead concentrations.

Link to the study

2- Cellular Cleansing

Cellular cleansing, or autophagy, is a natural process activated during fasting. Autophagy literally means "eating oneself": cells degrade and recycle their own damaged components (proteins, organelles, toxins, etc.).

Why is it beneficial?

Eliminates cellular waste.
Repairs damaged cells.
Strengthens immunity.
Protects against cellular aging.
Reduces inflammation and the risk of certain diseases (neurodegenerative, metabolic, etc.).

Autophagy is particularly stimulated after 24 hours of fasting, as the body, deprived of nutrients, draws on its internal reserves to cleanse and regenerate itself.

In short: during a fast, the body "sorts through its waste," recycles the old, and rebuilds itself in a healthier way. It's a powerful mechanism of natural regeneration.

3- Change of Fuel

Like cars, our bodies are hybrid machines. When the body is deprived of its usual fuel—glucose—it undergoes a metabolic switch, transforming the triglycerides in our fatty tissue into ketone bodies, our brain's preferred fuel. This occurs in several phases:

1. Transition phase (0 to 24h)

The body uses glucose (sugar) available in the blood and liver (glycogen).
Possible feeling of hunger, fatigue or irritability.

2. Ketosis phase (24h to 72h)

Glycogen stores are depleted.
The body switches to "fat-burning" mode, producing ketone bodies from fatty tissue.
Stable energy, reduced hunger, mental clarity.

3. Intensive cleaning phase (3 to 7 days)

Maximum activation of autophagy.
Recycling of damaged or useless cells.
Elimination of toxins, energy boost, overall well-being.

4. Stabilization phase (beyond 7 days)

Metabolism adapts: more constant energy, optimized vital functions.
Increased alertness, improved sleep, reduced pain.

5. Resuming eating (after fasting)

Crucial phase to gently reactivate digestion.
Gradual recovery with light and natural foods.
Consolidation of the benefits of fasting.

MUSCLE LOSS

This is a commonly held misconception. And yet, not only is there no "muscle loss," but the performance of the muscles of the lower extremities actually improves significantly after fasting, while that of the other muscles remains unchanged.

The average weight loss of 5.9 ± 0.2 kg results from 40% fat breakdown, 25% protein breakdown from metabolically active tissues: liver, kidneys, spleen, intestinal mucosa, heart, skeletal muscles, 8% liver and muscle glycogen, and 27% water elimination. Protein-sparing mechanisms are quickly established.

Link to the study