Ketosis in patients undergoing medically supervised therapeutic fasting—results from an observational trial



Medically supervised fasting has long tradition and broad acceptance in some European countries. The exact amount to which ketone bodies are produced as well as their possible contribution to beneficial effects in this procedure are open.


Open-label observational trial with in-patients undergoing medically supervised fasting with supplementation of approximately 40 g/d carbohydrates as part of an established routine care. Daily finger-stick blood samples for measurement of glucose and ß-hydroxybutyrate. Descriptive analysis for all data.


Complete sets of data of 17 patients (5 m, mean age 63.1) could be evaluated. Mean concentrations of ß-hydroxybutyrate rose continuously to a mean maximum of 3.6 mmol/L with an individual maximum of 5.1 mmol/L, while glucose decreased within normal range. Two patients with type 2 diabetes produced significantly less ß-hydroxybutyrate. Courses for ß-hydroxybutyrate and glucose showed a weak inverse correlation, while no serious adverse effects could be observed.


Medically supervised fasting with definite small amounts of carbohydrates by fluid intake may lead to limited increases of ketone bodies in their biopositive range, as known e.g. from epileptology or sports medicine. Clinical consequences deserve further research.

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Fig. 1: Course of glucose concentrations during fasting therapy.
Fig. 2: Course of ß-hydroxybutyrate concentrations during fasting therapy.


  1. 1.

    Wilhelmi de Toledo F, Buchinger A, Burggrabe H, Hölz G, Kuhn C, Lischka E. et al. Fasting therapy—an expert panel update of the 2002 consensus guidelines. Forsch Komplementmed. 2013;20:434–43.

    Article  Google Scholar 

  2. 2.

    Golbidi S, Daiber A, Korac B, Li H, Essop MF, Laher I. Health benefits of fasting and caloric restriction. Curr Diab Rep.2017;17:123.

    Article  CAS  Google Scholar 

  3. 3.

    Gormsen LC, Svart M, Thomsen HH, Sondergaard E, Vendelbo MH, Christensen N. et al. Ketone body infusion with 3-hydroxybutyrate reduces myocardial glucose uptake and and increases blood flow in humans: a positron emission tomography study.J Am Heart Assoc. 2017;6:e005066.

    Article  Google Scholar 

  4. 4.

    Buchinger O. Das Heilfasten und seine Hilfsmethoden als biologischer Weg. 26th ed., Stuttgart, Germany: Thieme Publishing Company; 2017. 152pp (in German).

  5. 5.

    Buchinger A. Fasting. In: Novey DW, editors. Clinician’s complete reference to complementary and alternative medicine. St Louis: Mosby; 2000. pp. 728–40.

  6. 6.

    A. Menarini Diagnostics s.r.l. GlucoMen LX Sensor, instructions for use. A. Menarini Diagnostics s.r.l.; 2015.

  7. 7.

    A. Menarini Diagnostics s.r.l. GlucoMen LX ß-Ketone sensor, instructions for use. A. Menarini Diagnostics S.r.l.; 2010 Menarini Diagnostics s.r.l.

  8. 8.

    Weichhart T. mTOR as regulator of lifespan, aging, and cellular senescence: a mini-review. Gerontology. 2018; 64:127–34.

    Article  CAS  Google Scholar 

  9. 9.

    Michalsen A, Li C. Fasting therapy for treating and preventing disease-current state of evidence. Forsch Komplementmed. 2013;20:444–53.

    Article  Google Scholar 

  10. 10.

    Ullah W, Hamid M, Mohammad Ammar Abdullah H, Ur Rashid M, Inayat F. Another “D” in MUDPILES? a review of diet-associated nondiabetic ketoacidosis. J Investig Med High Impact Case Rep.2018;6:2324709618796261.

    PubMed  PubMed Central  Google Scholar 

  11. 11.

    Gershuni VM, Yan SL, Medici V. Nutritional ketosis for weight management and reversal of metabolic syndrome. Curr Nutr Rep.2018;7(Sep):97–106.

    Article  CAS  Google Scholar 

  12. 12.

    Maalouf M, Rho JM, Mattson MP. The neuroprotective properties of calorie restriction, the ketogenic diet, and ketone bodies. Brain Res Rev. 2009;59:293–315.

    Article  CAS  Google Scholar 

  13. 13.

    Marosi K, Kim SW, Moehl K, Scheibye-Knudsen M, Cheng A, Cutler R. et al. 3-Hydroxybutyrate regulates energy metabolism and induces BDNF expression in cerebral cortical neurons. J Neurochem. 2016;139:769–81.

    Article  CAS  Google Scholar 

  14. 14.

    Wei M, Brandhorst S, Shelehchi M, Mirzaei H, Cheng CW, Budniak J. et al. Fasting-mimicking diet and markers/risk factors for aging, diabetes, cancer, and cardiovascular disease. Sci Transl Med. 2017;9:eaai8700.

    Article  CAS  Google Scholar 

  15. 15.

    Davids MR, Segal AS, Brunengraber H, Halperin ML. An unusual cause for ketoacidosis. Q J Med. 2004;97:365–76.

    Article  CAS  Google Scholar 

  16. 16.

    Bonikowska K, Magnusson P, Sjöholm A. Life-threatening ketoacidosis in patients with type 2 diabetes on LCHF diet. Lakartidningen. 2018;115:E4AD.

    PubMed  Google Scholar 

  17. 17.

    Turton JL, Raab R, Rooney KB. Low-carbohydrate diets for type 1 diabetes mellitus: A systematic review. PLoS ONE. 2018;13:e0194987.

    Article  CAS  Google Scholar 

  18. 18.

    Gomez-Arbelaez D, Crujeiras AB, Castro AI, Goday A, Mas-Lorenzo A, Bellon A. et al. Acid-base safety during the course of a very low-calorie-ketogenic diet. Endocrine. 2017;58:81–90.

    Article  CAS  Google Scholar 

  19. 19.

    Wilhelmi de Toledo F, Grundler F, Bergouignan A, Drinda S, Michalsen A. Safety, health improvement and well-being during a 4 to 21-day fasting period in an observational study including 1422 subjects. PLoS ONE 2019;2:14.

    Google Scholar 

  20. 20.

    Kitabchi AE, Umpierrez GE, Miles JM, Fisher JN. Hyperglycemic crises in adult patients with diabetes. Diabetes Care. 2009;32:1335–43.

    Article  CAS  Google Scholar 

  21. 21.

    Taylor MK, Sullivan DK, Mahnken JD, Burns JM, Swerdlow RH. Feasibility and efficacy data from a ketogenic diet intervention in Alzheimer’s disease. Alzheimer’s Dement: Transl Res Clin Interventions. 2017;4:28–36.

    Google Scholar 

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Generous financial support was given by Familie-Deutsch-Stiftung Berlin, Germany, a non-profit foundation for support of research in natural medicine. This article is published as part of a supplement sponsored by NuOmix-Research k.s. The conference was financially supported by Protina Pharmazeutische GmbH, Germany and Sirius Pharma, Germany, and organized by NuOmix-Research k.s. Neither company had any role in writing of the manuscript.

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Correspondence to Rainer Stange.

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Thaele-Franz, MA., Steckhan, N., Michalsen, A. et al. Ketosis in patients undergoing medically supervised therapeutic fasting—results from an observational trial. Eur J Clin Nutr 74, 43–47 (2020).

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