In this study, we demonstrated that Qigong Bigu practice for five days can lead to body weight loss, reduction of BMI and down-regulation of blood pressure in healthy adult participants. The blood BHB level increased to a physiological level after two days of Qigong Bigu practice (fasting and practice), while no symptomatic hypoglycemia and other significant side effects were observed, which suggests the safety of Qigong Bigu fasting. In addition, the calorie consumption was negatively related to the blood BHB level, while the body weight loss and decrease of BMI were positively related to the level of blood BHB.
The present results provide strong evidence to support our hypothesis that nutritional or physiological ketosis occurs during the initial five days of Qigong Bigu practice. Previous studies seldom showed these similar results. As blood ketone bodies have been demonstrated to have anti-seizure efficacy [19, 22], one could speculate that during the initial stage of Qigong Bigu practice, BHB might have potential to treat patients with epilepsy or other diseases. Further clinical trials in patients with different diseases are needed to verify the clinical use of Qigong Bigu practice.
In this study, Qigong Bigu practice decreased blood pressure in healthy adults, the blood BHB level was negatively associated with calorie consumption while positively correlated to the body weight and BMI loss. The underlying mechanism may be associated with decomposition of fats that produces ketone bodies. The BHB level was neither related to the systolic blood pressure nor the diastolic blood pressure after five days of practice, suggesting that other unknown mechanisms such as the over-activation of sympathetic nervous system might be involved. However, the lowering of blood pressure might contribute to the neuroprotective effect of KDT, since hypertension is one of the important comorbidities in young adult epilepsy patients  and may lead to cerebral damage, thus lowering the threshold of seizures . Seizures are accompanied by blood pressure elevation because of increased sympathetic tone . Furthermore, the increased sympathetic tone is associated with SUDEP . If Qigong Bigu practice could lower the blood pressure in patients with epilepsy, then it may be helpful for seizure control in epilepsy, and even for prevention and treatment of SUDEP.
The ketogenesis demonstrated in our study should be investigated further in future studies. Based on the benefits of fasting in patients with diabetes mellitus and epilepsy, the ketogenic diet was proposed in 1920s [23,24,25]. Now KDT is widely used to treat epilepsy [22, 24, 26,27,28,29], to rescue intractable status epilepticus [23, 30], and serves as an addition to control infections and diabetes mellitus [24, 25]. Moreover, ketogenic diet is the first-line therapy for glucose transporter type 1 deficiency syndrome, pyruvate dehydrogenase deficiency syndrome, some mitochondrial diseases and genetic diseases which currently have no treatment available . Although mechanisms remain to be fully revealed, KDT studies have demonstrated that the anti-seizure and neuroprotective effects are related to ketone bodies . Ketogenic diet could postpone aging , improving cognition through inhibiting excessive activation of mammalian targeted protein of rapamycin . Therefore, the loss of body weight and BMI index, and nutritional ketosis during Qigong Bigu practice suggest potential application of Bigu to treat various diseases, including metabolic syndromes. The present study also evidenced that Qigong Bigu practice could be a new approach for health care. Our results are consistent with previous finding that intermittent low calorie food intake in a five-day period could stabilize blood pressure, decrease body weight and BMI index, and lead participants into a nutritional ketosis state . One could speculate that ketosis is a common basic mechanism for both Qigong Bigu practice and KDT.
In Qigong Bigu practice the outcomes are mainly evaluated by clinical observation, and rarely by blood biomarkers. As the ketone bodies are negatively related to energy intake while positively related to body weight loss and BMI reduction, they may be a biomarker in the initial stage of Qigong Bigu practice. Thus, the use of ketone bodies as a biomarker may help standardize the protocols of Qigong Bigu practice.
Our research had limitations. The study was carried out in healthy subjects rather than in patients with hypertension or epilepsy or other diseases, and the sample size was small. Although only short period of fasting was employed in our study, during which we found connections between Traditional Bigu and KDT, ketosis might be a common mechanism, regardless of the fasting time. Future multicenter studies with large sample sizes that monitor blood ketone bodies, fatty acid and other biomarkers of Multi-Omics are needed to clarify the efficacy and mechanisms of Traditional Qigong Bigu practice in different diseases. The relationship between Qigong Bigu practice and KDT also deserves further investigation.