(Mal)adaptive responses to nutrition and energy balance are driven by the regulation of gene expression. Whereas these (mal)adaptive responses are reasonably well characterised at the genome level, regulation by the epigenome is less well understood. Epigenetic control mechanisms include microRNAs (miRNAs), and since the discovery of miRNAs two decades ago (Lee et al., 1993), an increasing number of research groups have started to investigate miRNA regulation of gene expression in various contexts. MiRNAs exist in both tissue and the circulation, although their mechanism of action is confined to tissue. Given that skeletal muscle accounts for ~75 % of non-oxidative glucose disposal in the postprandial state (Björnholm & Zierath, 2005), measurements of gene expression and post-translational modification in skeletal muscle are often made in studies investigating insulin sensitivity / resistance. However, post-transcriptional regulation, and in particular miRNA regulation, of gene expression has been less well studied within the context of insulin sensitivity. Only in the past 5 years or so has the role of miRNAs within type 2 diabetes (T2D) pathology been highlighted. Some researchers have now even suggested that T2D may be considered a miRNA-related disease (Guay et al., 2011). Thus, the impact of skeletal muscle miRNA regulation in insulin resistance pathology is apparent. Adipose tissue, liver and pancreatic β cells, like skeletal muscle, are involved in the regulation of energy excess and T2D pathology. Considering (mal)adaptive responses to energy excess span several tissue types, plasma miRNAs may be involved in this whole-body response – essentially communicating between insulin-responsive tissues (Ortega et al., 2014). MiRNAs have been implicated in cell-cell communication (Turchinovich et al., 2013) and are actively secreted into the circulation, rather than released in a non-specific manner, from tissue (Mittelbrunn et al., 2011; Rayner & Hennessy, 2013). For these reasons, plasma miRNAs may be useful biomarkers of a variety of adaptations. Data are beginning to accumulate to suggest that different miRNAs may be involved in the regulation of gene expression along the continuum between initial development of insulin resistance and manifest T2D. However, the impact of short-term high-fat energy excess (HFEE) as a model for insulin resistance development and / or the impact of glucose consumption on plasma and skeletal muscle miRNA levels in humans is currently unknown. We investigated changes (basal and following oral glucose consumption (OGTT)) in miRNA levels following 6 d HFEE (150 % habitual energy intake; 60 % of energy from fat) in non-active, healthy males (n = 20). Ten of twenty participants consumed 10 % of total fats from fish oil (FO) sources. FO consumption was included in this subset of participants to ascertain whether changes in dietary fat consumption modified insulin sensitivity change and / or altered miRNA profiles. We hypothesised that plasma and skeletal muscle miRNA levels would be altered by HFEE (both basal and the OGTT response) and that some associations would exist between miRNA levels in different sample types and insulin sensitivity change. We demonstrate that levels of a number of miRNAs were significantly altered by HFEE in skeletal muscle (miR-106b-5p, miR-214-3p, miR-215) but not plasma. Certain miRNAs were responsive to the OGTT including miR-145-5p (plasma) and miR-193a-5p, miR-206 (skeletal muscle). No miRNAs in either tissue type were solely group-responsive; however, several group interactions existed with HFEE and / or the OGTT (miR-7-5p, miR-27a-3p (plasma), miR-18a-5p, miR-145-5p, miR-214-3p (skeletal muscle)). Basal levels of miR-145-5p (plasma) and miR-204-5p (skeletal muscle) significantly predicted 16-23 % of the change in HFEE-mediated insulin sensitivity. Certain miRNAs may be useful markers of the high-fat overfed state (with or without FO), the response to oral glucose consumption and / or the combined influence of these. However, clear associations between plasma and skeletal muscle levels of these miRNAs are lacking, suggesting that investigation of these plasma miRNAs within the context of HFEE may not inform functional outcomes within skeletal muscle, but may better relate to other tissue types.