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Buchinger Wilhelmi Therapeutic Fasting: Key to a longer life? We tried it.

Intermittent fasting, alternate-day fasting, daily time-restricted feeding - the magazines are full with these latest diet trends. Driven by the megatrend health and the desire of a long life in health more an more people are trying various fasting forms. One fasting form is therapeutic fasting: This form was developed 100 years ago by Dr. Otto Buchinger. As a nutrition expert I find it fascinating that the human body can easily adapt to a low-calorie diet. But, how does it feel to just eating 250 calories a day for 10 days? I tried it - at the Buchinger Wilhelmi clinic at Lake Constance. When I told my friends about my upcoming stay, many of them were concerned and questioned whether I really needed the fast. "You don’t need to lose weight” was a popular response. A common misconception of fasting is to do it to lose weight. While that may be one of the results, there are many other health benefits and I wonder: Do we need to eat 365 days a year, 3 times a day?

Fascination fasting – or scientific evidence after all?

I have been curious about fasting since I was a student. Epidemiological studies have shown that populations who fast for religious reasons once a year during Easter or Ramadan, have a higher life expectancy compared to populations who do not fast at all. Scientists were able to confirm the findings of those studies on a cellular level. Due to the lack of carbohydrates, fats, or protein during fasting the body begins to break down body fat stored in the body’s own fat tissue. Fatty acids and triglycerides are produced in this process and used for energy production. Also, the liver metabolizes the fatty acids into ketones. This metabolic switch is what makes fasting so unique. The ketones are used by the brain to produce energy and to improve brain function. The body also synthesizes the ketones into molecules stimulating autophagy. During autophagy cell components are broken down and recycled (e.g. to provide the body with energy). In addition, the antioxidative capacity of the cells is increased. All of this has a positive impact on health and aging. The data surrounding these metabolic processes is relatively new: In 2016 cell biologist Yoshinori Ohsumi received the Nobel Prize in medicine for his work on autophagy – the “self-recycling” of the cell.

47 metabolic processes and our brain benefit from fasting

As a preliminary "health" check before my stay I received a list with indications and contra-indications: Therapeutic fasting has a positive effect on 47 (pathogenic) metabolic processes – from cardiac insufficiency, back pain, migraine, chronic-inflammatory gastrointestinal diseases, acne to depression. On the contrary, there are only six contra-indications (see below). Quite impressive, all my concerns have been vanished. BTW, losing weight is not on the list.

Fasting has a beneficial impact on the diseases stated above. Fasting therapy is contra-indicated in cachexia, anorexia nervosa, decompensated hyperthyroidism, advanced cerebra-vascular insufficiency or dementia, advanced liver or kidney failure, and pregnancy and lactation.

How I experienced 10 days of therapeutic fasting

Arrival (Day 1): On Saturday afternoon, I arrived at the clinic in Überlingen at Lake Constance. My feelings vary between pleasant anticipation and concern. I am looking forward to switching off and doing something to support my health. At the same time, I am worried about how I will get through this period if everything to do with food – the pleasure, the taste, wine, coffee - is cut out for a total of 10 days! I tried to plan a shorter stay, but the medical team kindly informed me that I had already booked the shortest version of the therapeutic fasting program. According to Dr. Otto Buchinger (1878 - 1966), the ideal fasting duration is 2 - 4 weeks. Therapeutic fasting for less than ten days is not healthy for the body or mind. For the first time in my life, I am interested in calories and want to know how many calories I get to eat the next day: A total of 400 kcal throughout the day. Oh, this is going to be tough.

The interior of the clinic is modern, like a 5-star-hotel, and invites one to enjoy the view of the lake. There is an apple in my room, which I eat - without thinking about it. Dinner is served in the so-called restaurant. Here you can find everyone who has started or ended their therapeutic fasting program. The restaurant is sparsely furnished and not very welcoming. I am assigned to a table with two other women who are similarly starting the therapeutic fasting with me. We get to eat a lot of vegetables – raw and cooked – and wonderfully palatable. Chef Phillipp Troppenhagen, who has worked in leadership positions of fine dining restaurants for many years, and the team of dietitians serve wonderful, nutrient-rich dishes. At the table, we speak about our fears to fast - for the first time.

Day of relief (day 2): On Sunday, there is a lot to organize. First, I have a meeting with the nurse in charge to record my pre-fasting blood pressure and body weight. We will continue to do this every morning. Afterwards, I am having my last breakfast, a big plate of fruit. Then I fill out a detailed medical history form. It feels nice to be asked about my health and well-being in a holistic way. For 50 minutes I thoroughly discuss the form with my assigned physician specializee in fasting. As my objective is not to lose weight, I follow a slightly modified fasting protocol consisting of 400 kcal per day. Therapeutic fasting according to Dr. Otto Buchinger recommends 250 kcal per day derived from freshly prepared, low-sodium vegetable soups and juices, as well as at least 3 liters of beverages, specifically herbal tea or water. Alkaline food supplements are taken daily to avoid over-acidification of the body. Nevertheless, the doctors adapt the therapeutic fasting parameters to suit each individual uniquely.

As the day goes on, concern rises within me. The last meal is coming up. Moreover, another unpleasant topic is giving me pause. There is to be a defecation (emptying of the bowel). Wouldn’t it be nice to do therapeutic fasting without this process? To ease my mind, I call fasting-expert and influencer Laura Junge to ask her what she recommends (sodium sulfate, laxative drops, or enema). We talk for a bit, and I decide to ingest laxative drops as they cause less headaches.

First day of fasting (day 3): For the first time since my arrival, I got up without a headache even though I did not sleep much. I had trouble falling asleep and woke up early. Contrary to what is often reported, I did not have intense dreams (nor did I have the rest of the week). For “breakfast” I get a cup of tea (herbal, of course) and drink it on the terrace overlooking the lake. Then I go to the gym and attend two sports classes. At noon I go to the salon to have "lunch". I get to choose between a freshly squeezed juice or soup (very thin and poorly salted). The salon is furnished like a living room, with armchairs, small tables; soft, live piano music is in the background. I meet my new friends from the first evening and other participants. I enjoy the exchange with the other people in the clinic. The conversations are straightforward and very open. It didn’t take long for us to talk about the reasons why we are here. This resulted in profound and pleasant conversations that were neither too much nor too intense.

The Buchinger-Wilhelmi team interviewing me during the fast (wasn't my best day) ;).

Second day of fasting (day 4): On my second day of fasting, I have a full program: I attend some of the weekly program activities such as yoga, a mindfulness-workshop, Taizé singing and autogenic training in the evening. The schedule of the weekly program is appealing to me, yet from now on I decide to take a break from the weekly program and just enjoy the moments. Am I hungry? No. I think of a meal now and then, but I am not hungry. I am getting to know more people who are fasting with me at the same time. Many have already been here several times. That is exactly what makes the Buchinger-Wilhelmi method so special. It works not only physically but also mentally due to the strong and unique bond forming between the participants. Creativity is the third pillar of the Buchinger Wilhelmil method: I find inspiration in the studio, where I am given free rein to create through painting and other creative mediums.


Third day of fasting (day 5): I have developed my routine and enjoy my daily schedule: Morning check-up with the nurse, breakfast tea, reading, soup in the salon, resting in bed with a warm liver cloth*, afternoon tea, swimming in the warm pool for 30 minutes, gazing into the sun, evening soup and inspiring conversations with the others in the clinic.

*Up to now there is no scientific evidence for the effect of a liver cloth. There is, however, evidence that heat stimulates regenerative processes in the liver.

Fourth day of fasting (day 6): I didn’t sleep well again and feel exhausted. I am in a bad mood. Interestingly, the others I talk to feel the same way. We seem to have the so-called “fasting low”. We feel unwell, but not too unwell that we would think of quitting. No one seems to want to exit prematurely.

Fifth and sixth day of fasting (day 7 and 8): I feel much better the next day and enjoy my stay again. I examine the scientific evidence on the Buchinger Wilhelmi method more thoroughly. To date, there are 15 publications by the clinic. Since 2006, the clinic's scientific director, Dr. Francoise Wilhelmi de Toledo, has been campaigning for more scientific evidence on therapeutic fasting. The patients of the clinic are to profit from the most recent scientific findings in medicine and research. In addition, the clinic's management and board of directors are committed to educating physicians, nutritionists, and health professionals about the positive effects of fasting on many chronic diseases. Every other year, Buchinger Wilhelmi organizes the international scientific congress on fasting. Scientists are invited to present their research results and discuss them with medical practitioners.

Breaking the fast (day 9): I join the two-hour hike through nature at 9 am. I am afraid of hypoglycemia or circulatory problems. But I experience nothing like that. I feel strong, fit, alert, and full of joy! This is probably the so-called “fasting high”. We get back from the hike around noon. I get my first "solid" meal, applesauce with two nuts. I am happy: I can eat again. There is an apple in my room. My stay ends as it began - with an apple.


After a so-called build up day (day 10) with 800 kcal, I leave the clinic on day 11 in the morning. On my way back, my head is spinning: Are our common dietary recommendations to eat three times a day up to date? And does our body benefit from the amount of carbohydrates that is recommended by us experts? Will the food pyramid of the future recommend periods of fasting? I'm going to get a coffee first, I think. Then I realize that I am perfectly fine with my water bottle. Coffee tomorrow, maybe.


Nutrition Hub met Dr. Francoise Wilhelmi de Toledo during the online event "Debunking the Myths of Fasting", for which we invited her as a speaker. This led to a lively exchange on the topic of fasting, and Simone's interest in experiencing therapeutic fasting for herself grew. This article describes Simone's experience of the compact fasting program, a condensed form of therapeutic fasting. The Buchinger-Wilhelmi-clinic financed her stay.

This report was written by Dr. Simone K. Frey, founder of NUTRITION HUB.

Dr. Simone K. Frey, Managing Director NUTRITION HUB
Dr. Simone K. Frey, Managing Director NUTRITION HUB


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