Fasting Guide

Everything you need to know about a break for body and mind.

Every year millions of people around the world fast, for religious, cultural or very personal reasons. Many use the traditional fasting period to give up everyday vices, certain foods or environmentally harmful things for a while. For many it is above all a chance to look more consciously: at what they eat and at their everyday life.

Why fast?

  • Everyday life can be quite exhausting. Stress at work, family appointments, household chores that need doing. A conscious break does you good. Juice fasting is one way to take that break.

  • Fasting has deep roots in many cultures around the world. In Germany the best-known form is multi-day fasting according to Otto Buchinger.

  • What forms of fasting are there?

    Unlike classic fasting, with juice fasting you do not go entirely without food: you drink cold-pressed juices from fruit, vegetables and roots spread over the day. Juices also play a role in so-called carbohydrate-modified fasting, but mainly on the relief day and the build-up day.

  • Experience hunger and fullness more consciously

    During the fasting days you quickly notice when you are really hungry and when it is more appetite. You can take that feeling with you after fasting.

Information on Buchinger fasting and a scientific assessment is available from, among others, the German Nutrition Society

  • “[Fasting] may … possibly be a starting point for changing one's diet.”

    German Nutrition Society (DGE)

Scientific Studies on Fasting

Fasting is a big topic in research. The largest observational study so far followed 1,422 people who fasted for 4 to 21 days according to Buchinger in a clinic, with freshly pressed organic juice as a fixed part of the day. Weight, waist circumference and blood pressure fell, physical and emotional well-being rose, and 93.2% reported no hunger (Wilhelmi de Toledo et al., PLOS ONE 2019). Researchers explain such effects with a change in metabolism, the “metabolic switch” (de Cabo and Mattson, New England Journal of Medicine 2019).

The study ran in a fasting clinic with medical supervision and no comparison group. Many questions are still open, especially about longer periods and fasting without medical supervision. More in our article Therapeutic fasting with juice.

Fasting Facts

  • 1. A doctor made fasting popular

    Otto Buchinger, himself a doctor, made multi-day fasting with juices and vegetable broth popular in Germany. Many of today's forms of fasting go back to his method.

  • 2. Fasting has historical depth

    The practice of conscious renunciation is mentioned in the earliest historical records from antiquity. The traditional Christian month of fasting, or the Muslim Ramadan, are a result of these customs.

  • 3. Fasting is also a matter of the mind

    At first, going without often takes an effort. After a few days many people experience the fasting period as calmer and clearer and feel a sense of freedom and inner calm.

  • 4. Fasting takes preparation

    Prepare well and plan a few quieter days. Especially at the start, side effects such as tiredness or mild headaches can occur. If you are pregnant or breastfeeding, take medication regularly or have a chronic illness, talk to your doctor first.

  • 5. Fasting is not a diet

    A fasting cure is not a diet but a conscious break of a few days. Many use it as a starting point to eat differently afterwards: more vegetables, less sugar, more mindful portions.

Fasting from A to Z

A. Losing weight and fasting

For many, losing weight is not the real goal of a fasting cure. What matters is what comes after: if you quickly fall back into old habits, you take little away from the fasting period.

B. Buchinger Fasting

Fasting according to the Buchinger method is a holistic fasting concept and one of the best-known methods. For five days or longer you only take vegetable broth and diluted juices. So instead of a zero diet, there is liquid with few calories.

C. Christianity and Fasting

The Christian Lent is a period of abstinence lasting forty days, from Ash Wednesday to Easter. In the past, strict rules of abstinence were observed to reflect and re-center oneself. Nowadays, Christian fasting rules are less strict. Many people voluntarily choose to give up sweets or alcohol.

E: Duration of fasting / Optimal fasting duration

Every fasting period has three phases: relief, fasting and build-up. How long you fast depends on you and your experience. A single juice day is enough to try it; three days are a good start for your first juice cleanse. With more experience, five or six days work too. Instead of fasting for a very long stretch, you can also fast more often and for shorter periods.

Which cleanse fits which duration you can see in the comparison on our juice cleanse page.

E: Release Day

The relief days usher in the fast and prepare you for the fasting period. You already eat a little lighter: more fruit, vegetables and water, less coffee, alcohol, sugar and meat. That makes it easier to start the fasting days.

Q: Fasting for beginners

Fasting is something everyone can try once. At first it can take some effort, especially for beginners, but it is worth it. It is important to prepare well and know the basic rules. Beginners should not start with two weeks straight away; three days are enough for a start. If you like, you can take a break for fasting twice a year. Fasting tip: fasting together in a group motivates you and helps you keep going.

G: Fasting well prepared

Before you fast, a quick check is worth it: if you are pregnant or breastfeeding, take medication regularly, or have or have had a chronic illness or an eating disorder, please talk to your doctor first. Fasting is not meant for children and teenagers. Plan quieter days, drink enough and listen to your body.

H: Hildegard of Bingen Fasting Method

Fasting according to Hildegard von Bingen is a very gentle form of fasting. The concept combines conscious abstinence with time for rest and reflection.

I: Intermittent fasting

Intermittent fasting, also called interval fasting, describes less a particular form of fasting than a particular eating rhythm. Compared with multi-day fasting programmes, which are often done a few times a year, intermittent fasting is a regular form of fasting that can be built into everyday life in the long term if you wish. You go without food for hours or days at a time. Intermittent fasting is divided by the time windows in which you eat or do not eat.

VERY POPULAR: THE 16:8 METHOD

The 16:8 method is probably the most common form of intermittent fasting and is often seen as the beginner's version. The 16 stands for the 16-hour window in which you take in no calories. In the remaining 8 hours, eating and drinking are then allowed. With 5:2 intermittent fasting, on the other hand, you go without food two days a week, or take in at most 500 kcal, while eating normally on the other five days.

J: Yo-yo Effect with Fasting

The yo-yo effect is unwanted weight gain after a diet, where the final weight is often higher than the starting weight. It is the body's reaction to a badly done diet, especially if you fall back into old habits afterwards. Fasting done properly is not a crash diet. Rather, it is about a lifestyle you can keep up in the long run. With a balanced diet and enough exercise, the yo-yo effect is easier to avoid in the build-up phase.

K: Fasting cure

A fasting cure is a consciously chosen period of fasting. You don't have to go to a spa clinic or an expensive hotel for this; you can fast comfortably from home. In your familiar surroundings, you can carry out the fasting phase exactly as you wish. However, you should fast under guidance so that you prepare yourself step by step.

L: Eating again slowly

After fasting you start again slowly. On the first day after, something light such as steamed vegetables, a soup or an apple works well. Bigger meals are better one or two days later.

M: Fasting with broth

Many forms of fasting are liquid only. Depending on the method, one of the fasting drinks is often a broth or fasting soup. Warm vegetable broth warms you from the inside and brings something savoury to the fasting days.

EN: Fasting Side Effects

Every body reacts differently to fasting. Especially in the first days, side effects such as headaches, tiredness, dizziness or weakness can occur, but do not have to. They usually fade when the fasting period ends. If symptoms are strong or do not fade, stop fasting and talk to your doctor. What helps with headaches is in our article Headaches during a juice cleanse.

O: Fasting Without Muscle Loss

There are many myths about muscle loss during fasting. It is true that multi-day fasting can lead to slight muscle loss. The exact extent depends on the duration and phase of the fast. But if you fast for only a few days and build enough movement into your day without overdoing it, you need not worry seriously about muscle loss.

P: Fasting Program

Fasting is much more than simply not eating. A programme with a plan helps you: you know what to drink when, how to prepare and how to start eating again afterwards. For every I·DO cleanse there is a guide on our page All juice cleanse guides.

R: Fasting Retreat

Fasting experiences for body and mind are often offered in the form of fasting retreats. A retreat in general is primarily a phase of relaxation, rest, and withdrawal from everyday life. Fasting retreats can be conducted either in special hotels or facilities or conveniently from home. You decide where you want to enjoy your retreat for this fasting experience.

T: Juice cleanse

With a juice cleanse you replace your meals for a few days with cold-pressed organic juices. You also drink water and unsweetened herbal tea. Many use the cleanse as a conscious break from everyday eating and as a fresh start for their eating habits.

E: Fasting tea

Since you consciously go without solid food while fasting, it is all the more important to drink enough. Unsweetened herbal tea is a good companion and brings a little aromatic variety to the fasting period.

U: Fasting Holiday

For a fasting experience, you can, but don't have to, take a vacation. There are fasting programs specifically designed to be carried out during everyday life. Those who choose to completely withdraw from their usual daily routine can also book a fasting retreat away from home.

W: What's allowed when fasting?

What exactly is allowed during fasting depends heavily on the fasting method. With all fasting methods, drinking water and unsweetened teas is permitted. Fasting concepts that significantly reduce calorie intake and rely on liquid nutrition prioritize juices and broths. Other methods allow for further food intake in the form of fruit, steamed vegetables, rice, and potatoes. However, with common forms of fasting, alcohol and cigarettes should be avoided.

Y: Yoga

Yoga is a meaningful addition to fasting. In fasting as in yoga, we turn our attention to ourselves and devote ourselves to body and mind. Yoga is a gentle way to move that fits well into the fasting experience.

E: To fast at home

You can fast anywhere you feel comfortable and safe. The familiar surroundings of your own home therefore offer many advantages. If you fast at home, you should, especially as a beginner, fast under guidance. With a little preparation or the right provisions, you will easily master fasting at home. Decide which method is right for you, how long you want to fast, and choose a period without important appointments.

I·DO Juice Cleanses at a Glance

Juice cleanses for three days or longer: we have the right cleanse for you.