Investigation of the Relationship Between Peripheral and Central Metabolic Changes Caused by Fasting

Investigation of the Relationship Between Peripheral and Central Metabolic Changes Caused by Fasting

Fasting has become an increasingly popular intervention for improving both physical and mental health. This study aims to explore the biological mechanisms underlying the positive effects of low caloric fasting (Wilhelmi-Buchinger-fasting). Specifically, we focus on the metabolic transition from glucose to fat utilization and its effects on systemic and brain metabolism. By examining the relationship between peripheral metabolic changes and brain metabolism, this research aims to uncover how these shifts influence brain metabolism and behaviour.

Therapeutic fasting, specifically Buchinger fasting, is a widely recognized method in integrative medicine. It is frequently used to treat a variety of chronic diseases, including inflammatory and metabolic disorders. In addition to its benefits for physical health, fasting is increasingly recognized for its potential to improve mental health.

Research has shown that fasting can induce significant biological effects, including the metabolic switch, which involves the transition from glucose to fat as the primary energy source. This shift typically occurs around day two of the fasting period and has important implications for peripheral metabolism. However, little is known about how these peripheral metabolic changes are linked to brain metabolism and how this connection might affect brain network function and, ultimately, psychological and cognitive processes.

Recent studies have shown that fasting influences both peripheral metabolism and brain function, with potential benefits for mental health. The precise mechanisms and timing of these changes remain unclear. The current study will focus on understanding (i) how peripheral metabolic changes during fasting relate to central metabolic changes in the brain, (ii) how these changes affect brain network function over time, and (iii) the connection between these metabolic and functional brain changes with psychological and cognitive alterations during fasting.

This study will use detailed metabolic profiling and neuroimaging techniques, alongside psychological assessments, to explore these complex interactions in healthy, fasting individuals, providing a foundation for further research into its potential as an intervention for mental health disorders.

Inclusion Criteria:

• Normal weight at study inclusion (BMI 18.5-25)
• Generally good physical condition without serious previous illnesses
• For female participants, only participants taking hormonal contraception are included

Exclusion Criteria:

• MRI contraindication: cardiac pacemakers, hearing aids, neurostimulation, insulin pumps, other potentially ferromagnetic implants, screws, clips, prostheses, metal splinters, etc., pregnancy, claustrophobia, extensive tattoos, medication that impairs thermoregulation
• Comorbidity: neurological or psychiatric conditions, cognitive impairments, chronic somatic disorders
• Intake of more than 40g of pure alcohol (for men) or more than 20g of pure alcohol (for women), smoking, regular drug use
• Pregnancy or nursing
• Current or within the past five years eating disorder, vegan diet or fasting within the past six months
• Regular medication intake