Diet, Liver Fat, and Metabolic Health: Insights from integrated human dietary intervention and cohort studies leveraging circulating metabolomics and adipose tissue transcriptomics

This thesis aimed to gain insights into interactions between diet and metabolic health, with a focus on adipose tissue and liver, by integrating different study designs and omics. The key objective was to identify potential leads towards the mechanisms underlying liver fat accumulation, and to explore how dietary exposure relates to changes in cardiometabolic health. Liver fat accumulation was associated with distinct alterations in adipose tissue and circulating metabolism both fasting and postprandially. Whole-grain wheat consumption modulated adipose tissue pathways involved in energy and lipid metabolism, providing potential insights for its protective effects against liver fat accumulation. Furthermore, a metabolite-based Score (MED-MScore) was developed as an objective marker of Mediterranean diet exposure. Across various populations, a higher MED-MScore was associated with healthier dietary intake, improved metabolic health markers, including lower liver fat, and a reduced risk of incident type 2 diabetes and cardiovascular disease. Collectively, these findings deepen our understanding of diet–metabolic health relationships.