Practical Guide · Integrative Medicine
Fasting,
a healing pause
Understand, prepare for, and confidently experience your fast at home
This guide is for educational purposes. It does not replace personalized medical supervision. Consult your doctor before any fast, especially if you are taking medication, suffer from a chronic condition, or are pregnant. If in doubt or if you experience any unusual symptoms, stop the fast and seek medical advice.
Why Fast
What happens really
inside your body
When the body stops receiving food, it doesn't weaken — it turns to its own resources and triggers a remarkable process of cleansing and regeneration.
Within 24 to 48 hours, liver glycogen stores are depleted. The body then switches to an alternative fuel: fatty acids stored in adipose tissue. This is ketogenesis. At the same time, a fundamental cellular mechanism is activated:autophagy.
This dietary break isn't about deprivation — it's an invitation for the body to do what it does best: repair itself.
Yoshinori Ohsumi received the Nobel Prize for his work onautophagy — the process by which the cell digests and recycles its own damaged components. Fasting is one of the most powerful triggers of this mechanism, activated after just 16 to 24 hours of food deprivation.
Body & Metabolism
Decrease in blood sugar and cholesterol, reduction in blood pressure, burning of fat reserves from the 3rd day. The intestinal lining repairs itself and cellular junctions tighten — a profound benefit for all those who suffer from leaky gut.
Pathologies & Inflammation
Documented improvement for: hypertension, digestive disorders, allergies, eczema, psoriasis, migraines, rheumatism, fibromyalgia. Fasting acts as a natural anti-inflammatory by reducing the toxemic load on the organs.
Mental Clarity & Emotions
From the 3rd–4th day, serotonin secretion increases and ketone bodies nourish the brain differently. Most fasters describe a lightness, clarity of thought, and unexpected emotional stability.
Bigu — « Avoiding Grains »
In Taoist medicine and in the tradition of Traditional Chinese Medicine, fasting — known as bigu (避谷) — is an ancestral practice for purifying Qi. It aims to free the energy normally dedicated to digestion to redirect it towards organ regeneration and the circulation of vital energy. What modern science calls autophagy, TCM has been practicing for millennia.
Before You Begin
Am I ready to fast?
Take 2 minutes to check these points. Fasting is suitable for the vast majority of people in good general health — but some situations require caution or support.
✓ Favorable situations
- ✓ Good general health, without heavy medication
- ✓ Clear and sincere motivation (health, detox, mental clarity…)
- ✓ A calm period: little professional or family stress
- ✓ Ability to reduce physical activities during the fast
- ✓ A supportive environment or available guidance
- ✓ Having already experienced 12h or 24h fasting
✕ Absolute contraindications
- ✕ Pregnancy or breastfeeding
- ✕ Anorexia, severe bulimia, or cachexia (extreme thinness)
- ✕ Decompensated hyperthyroidism
- ✕ Severe kidney or liver failure
- ✕ Severe depression or active psychosis
- ✕ Type 1 diabetes (only in a supervised medical setting)
- ✕ Peritonitis or intestinal obstruction
Choosing your practice
Which fast is right for you ?
There is no single type of fast. Each form has its goals, its level of difficulty, and its target audience. Always start with the gentlest version.
Water fast
Water and infusions only · 0 kcal
The purest form of fasting: only water and herbal infusions are consumed. It is the most effective practice for detoxification and autophagy. Glycogen stores are depleted in 24 to 48 hours, forcing the body to switch to its lipid reserves.
It requires real preparation (a 7-day dietary taper), a calm period in your life, and ideally, prior experience with short fasts. The first few days can be uncomfortable — but the benefits are well worth it.
Modified juice fast
Fresh vegetable juice + water · ~250 kcal/day
The best entry point for a first fast. You retain most of the benefits of a water fast while providing directly absorbable vitamins, minerals, and enzymes. The golden rule: 80% vegetables, 20% fruit maximum, made with a juicer.
The psychological comfort is greater: the juice times replace meals and provide a structuring ritual.
Intermittent fasting
Reduced eating window · 16:8 or 18:6 protocol
Food intake is concentrated into a 6 to 8-hour window per day, leaving 16 to 18 hours for fasting. This is enough to trigger autophagy and improve insulin sensitivity, while remaining compatible with an active lifestyle.
Ideal for regular maintenance or as a first step before a longer fast. Very well-documented scientifically.
Mono-diet
A single food for one day · 650 to 900 kcal
Only one type of food is consumed — apples, brown rice, carrots, zucchini — which provides deep digestive rest while maintaining a minimal calorie intake.
An excellent "reset" day after an excess, to be done once or twice a week. A good introduction to fasting for complete beginners.
Complete program
From D-7 to D+7 — each step
This program details the water fast, the most complete form. If you choose a modified juice fast, the steps are identical — with fewer symptoms and more comfort. Click on each day for details.
The preparation phase is often neglected — and yet it largely determines the success of the fast. Over seven days, you will ask your body to slow down, digest less, and prepare to draw on its reserves.
D-7 to D-4: gradually eliminate red meat, cheese, alcohol, coffee, and refined sugars. Increase fresh fruits and vegetables, drink 1.5 to 2 L of low-mineral water per day.
D-3 to D-2: exclusively plant-based diet. Cooked or raw vegetables, fruits, salads. No more cereals, legumes, or animal proteins.
The evening before your fast, have a very light meal: a vegetable soup or broth, without protein. Around 10 PM, prepare and drink the purgative solution — a gentle laxative preparation that clears the intestines and eases the transition into fasting.
Purge Recipe — to be diluted in 500 ml of low-mineral water: 10 g of magnesium chloride, 10 g of magnesium sulfate, 10 g of magnesium citrate, 5 g of potassium citrate (from a compounding pharmacy). Drink 25 to 33 cl at bedtime.
If you cannot find the citrates, magnesium chloride alone is sufficient — its taste is bitter but its effectiveness is guaranteed. Plan to stay close to a toilet in the following hours.
The first day is often easier than imagined — and sometimes more difficult too. You might feel stomach rumbling, slight irritability, perhaps a headache at the end of the day. These are not signs of danger: it's your body weaning itself off its habits — coffee, sugar, stimulants. These sensations are temporary.
What is commonly called "hunger" at this stage is not actually true physiological hunger. True hunger only appears after several weeks of fasting. What you are feeling is more a lack of stimulation or transitional hypoglycemia. Drink an herbal tea, rest, and trust the process.
A hot bath with coarse sea salt (1 kg in the bathtub) is one of the best allies during a fast. Alkalizing, warming, stress-relieving — incorporate it every evening if possible.
The second day can be the most uncomfortable for some. Withdrawal symptoms may intensify: marked fatigue, feeling chilly, possibly nausea or diarrhea. Some women experience their period unexpectedly — this is normal and part of the elimination process.
Adapt your pace without feeling guilty. Avoid intense physical exertion. Remember: every symptom is a sign that your body is cleansing. This is not weakness — it is inner work.
Autophagy peaks around this second day: your cells are literally recycling their own waste. There is no dietary supplement in the world capable of causing this.
The third day is known to be the most trying — and also the most decisive. Your body switches to burning fat (ketogenesis): liver glycogen is depleted, and fatty acids become the main fuel. This transition can cause dizziness when changing positions, nausea, and a feeling of great weakness.
Good news: the feeling of hunger often disappears from this point on. The body has found its replacement fuel and is settling into it. A light 20 to 30-minute walk helps eliminate volatile acids through breathing. 20 minutes of meditation or slow breathing has the same alkalizing effect.
Walking 20 min outdoors or practicing slow breathing helps the body eliminate weak acids through the lungs — this is one of the most effective mechanisms for getting through this day.
→D+7
From the fourth day onwards, something changes. Symptoms fade, the mind becomes clearer. Many describe a lightness, a form of mild euphoria — this is the effect of ketone bodies nourishing the brain differently, while stimulating the production of BDNF, a protein that promotes neuronal plasticity.
This mental clarity is one of the great surprises of fasting for those experiencing it for the first time. Many make important decisions during this period, or find an unexpected serenity.
Continue to hydrate, walk gently, and rest. Gentle activities are welcome: yoga, slow swimming, a walk in nature. Enjoy this time for yourself — it is rare and precious.
refeeding
The first meal is not eaten at a table with cutlery and a plate. It is taken around 5 PM, in the form of a large glass of pressed green vegetable juice (celery, spinach, kale) with half an apple and a teaspoon of coconut oil. Your digestive system is as if asleep — let's wake it up gently.
The golden rule: as many refeeding days as fasting days. No animal protein before the 7th day at the earliest. Consult the dedicated section below for the full program.
Pouncing on a hearty meal after a fast can cause real abdominal pain and cancel out some of the benefits gained.
In the vast majority of cases, a one-week fast proceeds without serious complications. However, there are signs that require immediate cessation and a medical consultation.
Stop the fast and consult a doctor if: prolonged cardiac arrhythmia (several hours) · continuous vomiting preventing any rehydration for more than 12h · total absence of urine for more than 24h · petechiae (purple spots on the skin) with high fever · severe mental confusion or loss of consciousness.
During the fast
Water & infusions — your allies
Throughout the water fast, water and infusions are your only nutrients. Choose them well.
Chamomile
Calming, antispasmodic. Ideal in the evening for sleep and stomach cramps.
Lemon balm
Soothing for digestion, mild anxiolytic. Perfect for fast-related anxiety.
Horsetail
Remineralizing, rich in silica. Compensates for mineral loss during the fast.
Hawthorn
Heart-regulating. To be used for palpitations or tachycardia during the fast.
Thyme
Antibacterial, anti-inflammatory. Supports the bronchial tubes and the immune system.
Vervain
Aids digestion and relaxes the nerves. An excellent choice in the afternoon to soothe the mind.
💧 Which water to choose?
Not all waters are equal during a fast. As the kidneys work hard to eliminate acids, avoid waters that are too high in minerals.
- Dry residue < 50 mg/L : Mont Roucous (35 mg/L ✓), Montcalm (42 mg/L ✓), Volvic (109 mg/L, acceptable)
- Quantity: 1.5 to 2 liters per day — without forcing yourself. Listen to your thirst.
- Avoid highly mineralized waters: Hépar, Contrex, Badoit.
Breaking the fast
Refeeding — the master step
« Any fool can fast, but only a wise man knows how to break a fast properly. »— George Bernard Shaw
One day of refeeding for each day of fasting. For a 7-day fast → a minimum of 7 days of refeeding. No animal protein before the 7th day at a minimum.
First meal (around 5 PM)
Freshly pressed green vegetable juice — celery, spinach, kale — with 1/2 apple and 1 tsp coconut oil. No solid food.
Days 1–2
Juiced vegetables and fruits. Ripe, juicy fruits. Raw vegetables if tolerated. Goal: gentle remineralization.
Days 3–4
Cooked vegetables (carrot, celery, leek). Raw vegetables, green salad, olive or coconut oil.
Days 5–6
Sprouted seeds, nuts, avocados, oilseeds in moderation. Whole grains are a possibility.
Day +7
Return of light proteins: oysters, raw shellfish, white fish. Raw vegetables in abundance.
Day +10 and beyond
Very gradual reintroduction of white meat, then red meat. Gentleness remains key.
Superfoods for refeeding
Frequently asked questions
What you wonder often
Safety first
Signals emergency stop
These situations are rare. They shouldn't scare you — they should make you pay attention. If any of them occur, stop the fast and seek consultation without delay.
Prolonged cardiac arrhythmia
Mild palpitations are normal. However, an alternating fast/slow rhythm for several hours, or a heart rate below 60 bpm (unless you are a top-level athlete), requires a consultation. A hawthorn infusion can help in the meantime.
Continuous vomiting for more than 12 hours
If you are completely unable to rehydrate and have been rejecting all fluids for more than 12 hours, the risk of dehydration becomes real. Stop the fast and seek consultation.
Petechiae — purple spots on the skin
These small spots accompanied by a high fever and a state of prostration indicate serious capillary fragility. Immediate cessation of the fast required, urgent medical consultation.
Total absence of urine for more than 24h
Urine output naturally decreases during a fast but should not stop completely. If you do not urinate at all for more than 24 hours despite normal hydration, seek consultation.
Severe mental confusion or loss of consciousness
Feeling dizzy when standing up is common and benign. Significant mental confusion, disorientation, or loss of consciousness are not. Call for help if necessary.
Certified Traditional Chinese Medicine practitioner
Every constitution reacts differently to fasting. At the practice, a Chinese medicine assessment (pulse, tongue, constitution) helps adapt your fast to what your body can truly handle.
Published on 4 May 2026Updated on 10 October 2026