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Documentation: Repeated long-term fasting

mschellinger - 12/03/2024 - 0 comments


The world's longest clinical documentation of repeated, long-term fasting

Überlingen, 27.02.2024

Buchinger Wilhelmi clinics, pioneers in long-term therapeutic fasting, have announced the publication of the world’s longest clinical documentation of fasting in Friedrich Klapdor a 92-year-old man, who has fasted for 21 days a year over a period of 45 consecutive years.

While intermittent fasting has been extensively researched, only little scientific data has been published in peer-review journals on long-term fasting.

Friedrich Klapdor, the health-conscious man whose history of fasting has now been documented, has fasted at Buchinger Wilhelmi in Überlingen twice a year since 1969. He fasts for 21 days under medical supervision every spring and does a calorie-restricted, ovo-lacto-vegetarian organic diet (800 kcal), also for 21 days, every autumn. His unique case sheds light on the potential benefits of annual long-term fasting.

To document the current health status of this man who has fasted all his life, extensive examinations were carried out.

An epigenetic analysis indicated that his biological age was 5.9 years younger than his chronological age. Various tests to assess his mental and physical health revealed that he was able to function independently, had excellent cognitive abilities and good mobility.

Friedrich Klapdor with 22

Friedrich Klapdor with 92

Seasonal, prolonged fasting among animals living in the wild has been described scientifically in detail. Being able to fast when food was scarce and live off their energy reserves also played a decisive role in the evolution of humans. The results of the study confirm the assumption that humans have preserved this ability to manage periods of food shortage through long-term fasting to this day. Fasting triggers a profound metabolic reset, has anti-oxidative and anti-inflammatory effects, and promotes the regeneration of the cells, tissue and mitochondria.


Wilhelmi de Toledo F, Grundler F, Mesnage R (2024).

World’s longest medically documented repeated fasting history in a 92 years old man who fasted 21 days yearly for 45 years: a case report. Journal of Integrative and Complementary Medicine.

The results of the study were published in the Journal of Integrative and Complementary Medicine, an official journal of the International Society for Traditional, Complementary, & Integrative Medicine Research, and are freely available.

From the video media library

In an interview with Dr. Françoise Wilhelmi de Toledo, Friedrich Klapdor talks about how he began fasting at Buchinger Wilhelmi in 1970, why he returns every year, and how he got to know the Buchinger Wilhelmi family better over the years. Mr. Klapdor also reports on his excellent state of health and his secrets for living a long life.


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About Buchinger Wilhelmi

The Buchinger Wilhelmi clinics offer long-term fasting under medical supervision. The programme was developed by the clinics’ founder Dr. Otto Buchinger more than 100 years ago. Around 6000 patients currently visit the clinics to fast every year. The company regularly publishes the results of accompanying studies in peer-reviewed journals.


For media inquiries or additional information, please contact:

Dr. Françoise Wilhelmi de Toledo
Senior Scientific Advisor