Comprehensive Assessment of a Fasting-Mimicking Diet: Salivary Metabolite Profiles, Weight Loss, and Biomarker Analysis

Summary Fasting-mimicking diets (FMDs) have shown to result in various health benefits, including body weight reduction, body fat reduction, decreased blood pressure and longevity promoting effects through enhanced ketogenesis and reduced glycolysis. The direct impact of FMDs on metabolite fluctuations, however, remains elusive. Here, we explore the effects of FMDs on the human salivary metabolic profiles and weight in a single-arm case study. Specifically, we present a bio-energetic framework to estimate fat loss as a component of the sustained weight loss, the effects on metabolite quantities involved in energetic reprogramming and the effects on the abundance of metabolites originating from the gut microbiome. These findings highlight the importance of metabolic health tracking to further our understanding of the effects of fasting, personalized nutrition and effective preventive health measures. In brief Hof & Wall demonstrate that fasting-mimicking diets have short-term effects on the energy production, energetic reprogramming and gut microbiome output in humans by use of saliva metabolomics and nuclear magnetic resonance (NMR). Highlights 45% of total sustained weight loss could be attributed to fat loss as calculated by bio-energetic calculation framework Fasting-mimicking diets increase L-glutamine, L-glutamate and succinic acid indicating immediate effects on energy metabolism Fasting-mimicking diets increase short-chain fatty acids i.e. acetate, butyrate and propionate. Other gut microbiome metabolites are increased as well i.e. acetoin, fucose and ethanol.