Updated: October 2026
In short: Buchinger therapeutic fasting means getting by for several days without solid food, taking only tea, water, vegetable broth, a little juice and honey, at a maximum of 250 to 500 kcal a day. 7 to 10 days is usual, plus one preparation day and three refeeding days. The German Nutrition Society (DGE) recommends medical or professional supervision. As a weight-loss method, it is only conditionally suitable.
Otto Buchinger developed the method in the early 20th century, and his name still stands for classic therapeutic fasting. Here you get the day-by-day plan, answers on 3, 5, 7 and 10 days, allowed drinks, side effects and health insurance, and an honest assessment.
What is Buchinger therapeutic fasting?
According to the German Nutrition Society (DGE), therapeutic fasting is a form of fasting in which, unlike total fasting, the body is supplied with a small amount of energy. In its modern form it goes back to the physician Otto Buchinger (1878 to 1966). Allowed are water, herbal tea, vegetable broth, diluted juice and a little honey. There is no solid food.
The DGE sees therapeutic fasting as a method that should be supervised by a doctor or trained fasting leader. For lasting weight loss it is only conditionally recommended, but it can be a starting point for a change of diet. The Gesundheits-Lexikon stresses that it is not an evidence-based treatment concept. An overview of other forms is in Types of Fasting.
What does the therapeutic fasting plan look like day by day?
The classic process consists of preparation, fasting days and refeeding. The following example shows a plan for 7 fasting days according to the DGE.
| Phase | What happens |
|---|---|
| Day before | reduce energy to approx. 1,000 kcal, stop caffeine, alcohol and nicotine |
| Fasting day 1 | bowel emptying at the start, after consulting a doctor; then tea and broth |
| Fasting days 2 to 7 | daily 0.25 l vegetable broth, 0.25 l juice, 30 g honey and at least 2.5 l tea or water, maximum 250 to 500 kcal |
| Breaking the fast | slowly eat a raw or cooked apple, potato soup in the evening |
| Refeeding days 1 to 4 | about 800, 1,000, 1,200 and 1,600 kcal, light, vegetarian food |
The refeeding days are part of the concept. Spontaneous bowel movement should occur by the fourth day at the latest. You'll find recipes and tips for getting back to normal eating in Guide to Breaking a Fast.
How long does Buchinger fasting last: 3, 5, 7 or 10 days?
Classically, the DGE names 2 to 4 weeks. The Ärztegesellschaft für Heilfasten und Ernährung (the medical society for therapeutic fasting and nutrition) recommends 7 to 10 days as standard, plus one preparation day and three days to normalise eating behaviour. Shorter phases are easier to put into practice, and according to the DGE, healthy people benefit from them too.
| Duration | Assessment |
|---|---|
| 3 days | short version, mainly for beginners and planned as a weekend |
| 5 days | shortest group in the observational study by the Buchinger Wilhelmi clinic (5, 10, 15 and 20 days) |
| 7 days | lower limit of the DGE standard, upper limit without supervision according to the Verbraucherzentrale (about a week) |
| 10 days | upper limit of the standard, belongs under medical or professional supervision |
How many days suit you depends on experience and health. More in Fasting Duration.
What can you eat and drink during therapeutic fasting?
Nothing solid is eaten. You can drink water, unsweetened herbal tea, clear vegetable broth and, in small amounts, juice, ideally freshly pressed. The DGE names at least 2.5 litres of fluid a day, and so does the Verbraucherzentrale.
- Tea and water: at least 2.5 litres per day
- Broth: clear, fat-free, around 0.25 litres
- Juice: around 0.25 litres, honey up to 30 g
- Off limits: coffee, alcohol, nicotine, sugar, solid food
All drinks count toward the calorie total. To break the fast, you classically eat an apple, followed later by the potato soup.
Can you do Buchinger therapeutic fasting at home?
Healthy people can plan shorter fasting phases at home if they have sought medical advice beforehand. The Verbraucherzentrale advises healthy people not to fast for longer than about a week and to get medical supervision when going without food for several days. The DGE recommends medical care or trained fasting leadership for therapeutic fasting.
At home you need peace, warmth, time and enough drinks. The details for the process in your own four walls are in the Therapeutic Fasting Guide for Home and in Fasting Cleanse at Home.
What side effects does therapeutic fasting have and who shouldn't fast?
Common are low blood pressure, dizziness, tiredness, reduced concentration, feeling cold and gastrointestinal complaints, according to the Gesundheits-Lexikon. The complaints are usually reversible but can significantly affect daily life. Risks are muscle loss, electrolyte shifts and dehydration, low blood sugar in diabetes and raised uric acid in gout.
You shouldn't fast during pregnancy and breastfeeding, as a child or teenager, with eating disorders, serious organ diseases and pronounced malnutrition. With particular caution and medical monitoring: diabetes, gout, heart failure, kidney or liver disease and many medications. If you get dizzy, have a racing heart or persistent nausea, stop and seek medical advice.
How do you prepare for therapeutic fasting?
Start with a preparation or lead-in day. The DGE describes a reduction to about 1,000 kcal and stopping caffeine, alcohol and nicotine. Plan quiet days without time pressure, get tea, broth and juice, and have warmth ready, such as a hot water bottle and warm socks. Moderate exercise like walking is recommended by the DGE, while intense exertion should be avoided according to the Gesundheits-Lexikon.
Check with your doctor beforehand whether fasting is right for you, especially if you take medication. More on preparing for juice fasting is in the Juice Cleanse Preparation.
What does the evidence say about Buchinger fasting?
In a one-year observational study by the Buchinger Wilhelmi clinic with 1,422 participants and fasting periods of 4 to 21 days at 200 to 250 kcal daily, weight, waist circumference and blood pressure fell, blood sugar dropped and ketone bodies rose. The study comes from the clinic that offers the method and had no control group. Treat it as an indication, not proof.
The Gesundheits-Lexikon sums up that for multi-week therapeutic fasting there is no robust evidence of long-term benefit and that the method is not risk-free.
Does health insurance pay for therapeutic fasting?
Whether and how much your health insurer contributes depends on the insurer, plan and offer, for example with certified prevention courses. We haven't checked a reliable source on this. Ask your insurer directly before you book. More on this is in Fasting Cleanse and Health Insurance.
How does Buchinger fasting differ from a Juice Cleanse?
The biggest difference is the amount of energy. With therapeutic fasting it is a maximum of 250 to 500 kcal a day. With a Juice Cleanse from frank., the energy content is 650 to 845 kcal per fasting day, depending on the level.
| Feature | Buchinger therapeutic fasting | Juice Cleanse |
|---|---|---|
| Energy per day | 250 to 500 kcal | 650 to 845 kcal (frank.) |
| Drinks | Tea, broth, little juice, honey | Juices, tea, water |
| Supervision | medical or professional recommended | self-guided possible for healthy people |
| Duration | 7 to 10 days standard | 1, 3, 5 or 7 days |
Both are time outs, not therapies.
Matching picks from frank.
If you'd like to try fasting without extreme calorie restriction, the frank. Juice Cleanses in 3, 5 and 7 days with a guide for preparation and breaking the fast are an alternative. To get started, the 3-Day Juice Cleanse is a good fit.
You might also like
- Types of Fasting: Which One Is Right for Me?
- What Is the Optimal Fasting Duration?
- Our Guide to Breaking a Fast - Some Tips & Tricks
Frequently asked questions about Buchinger therapeutic fasting
How many kilos do you lose with Buchinger fasting?
That's individual. Part of the loss is water and bowel contents, and without a change of diet the weight often rises again afterwards. The DGE sees therapeutic fasting as only conditionally suitable for lasting weight loss.
Is Buchinger fasting the same as therapeutic fasting?
Buchinger fasting is the best-known form of therapeutic fasting. The term is also used for other methods, though.
How long should you fast according to Buchinger?
The DGE classically names 2 to 4 weeks, the Ärztegesellschaft Heilfasten und Ernährung 7 to 10 days plus preparation and three refeeding days. For healthy people without supervision, the Verbraucherzentrale advises about a week at most.
What do I eat after therapeutic fasting?
First an apple, potato soup in the evening, then four refeeding days with light food and rising amounts, about 800, 1,000, 1,200 and 1,600 kcal according to the DGE.
When do you stop fasting?
With dizziness, a racing heart, persistent nausea or marked discomfort. Then talk to a doctor.
Can I do therapeutic fasting alone at home?
Healthy people can plan shorter phases if they have sought medical advice beforehand. Longer cleanses belong under medical or professional supervision.
Note: This article is for general information and is not a substitute for medical or therapeutic advice. If you have complaints, pre-existing conditions, are pregnant or take medication, please talk to your doctor first.
