Background: Buchinger therapeutic fasting, based on a low caloric (<500 kcal/d) fluid diet (juice-broth), is a traditional natural-healing strategy to reduce body weight and cure cardiometabolic complications in obese patients. Although there are some anecdotal reports about a serious protein loss during this type of fasting, there are no validated data that support this claim.
Objective: Is Buchinger fasting associated with a critical protein loss and is this loss aggravated by additional endurance training which might lead to cardiac symptoms?
Patients and methods: A therapeutic concept for 'complex re-conditioning of obese patients', a combination of Buchinger fasting and endurance training was tested in obese patients for 28 days. Parameters of energy, carbohydrate, lipid, and protein metabolism were studied in several subgroups either with or without endurance training of defined intensity.
Results: Additional endurance training resultet in a greater loss of body mass (12.2 +/- 3.2 vs. 10.4 +/- 2.2 kg; p < 0.001) and fat mass (8.1 +/- 1.6 vs. 5.9 +/- 1.3 kg; p < 0.001), and in improved lipid utilisation, physical efficiency, and a smaller decrease in metabolic rate per kilogram fat-free mass (-7.6 +/- 12.4 vs. -14.3 +/- 12.2%; p < 0.001). Without training, total protein loss over 28 days was about 1,000 and 650 g for men and women, respectively. With training, there was an additional protein loss of 130 g / 28 d (p < 0.01) in men.
Conclusions: Endurance training is an important, safe and necessary component of a 28-day Buchinger fasting therapy.