InterVFast—effectiveness and acceptance of intermittent fasting in cardiac rehabilitation patients: study protocol of a randomized controlled trial

Abstract

Abstract Background Research on intermittent fasting has shown that it can improve a variety of health outcomes, including blood sugar control, blood lipid levels and blood pressure. Only few studies document longer periods of fasting, especially in rehabilitation participants. Cardiac inpatient rehabilitation follows a multidisciplinary approach including change of health behaviour to reduce patients’ risk of future cardiovascular events. To date, evidence suggests that intermittent fasting can be an effective way to improve health and well-being, but more research is needed to fully understand its long-term effects and factors that promote the implementation. Therefore, the aim of the ongoing InterVFast trial is to investigate the effectiveness of intermittent fasting amongst cardiac rehabilitation patients after 4-week inpatient rehabilitation as well as 3 and 12 months subsequently including patients’ perspective. Methods This single-centre randomized controlled trial evaluates the effectiveness of the InterVFast intervention in weight loss (primary outcome). We also examine patients’ acceptance and the effect on relevant outcomes as blood glucose and triglyceride levels, cholesterol and high-sensitivity C-reactive protein. Weight, blood samples and clinical data are collected as part of the initial and final examination during inpatient rehabilitation. During inpatient rehabilitation, participants daily note fasting intervals and meals eaten as well as practicability in a fasting diary. In addition, interviews about perceived advantages and disadvantages and acceptance are carried out with the participants in the IG. A standardized follow-up examination (weight, blood samples) will be carried out by the family doctor after 3 and 12 months (t2 and t3). Discussion Compared to other weight-loss intervention studies, our study addresses patients with coronary heart disease and includes patients’ acceptance as well as long-term maintenance. It is hypothesized that participation in the InterVfast intervention will improve relevant health outcomes in a sample of cardiac rehabilitation patients and thus constitute a behavioural prevention strategy to reduce the risk of future cardiac events and improve overall health and quality of life. Trial registration ClinicalTrials.gov DRKS00023983. Registered on February 17, 2022.