Diurnal Variation of Maximal Fat Oxidation in metabolic syndrome patients

Insulin resistance states, such as type 2 diabetes mellitus and metabolic syndrome (MetS), are characterized by mitochondrial dysfunction (MitoD) and poor capacity to oxidize fat. Furthermore, those patients with T2DM and MetS are overly reliant on Carbohydrates derived energy sources and possess limited ability to transition between Carbohydrate oxidation and FAT both at rest and during exercise, a state commonly known as metabolic inflexibility. In human adipocytes, genes implicated in fatty acid metabolism show transcriptomic rhythmicity, indicating lipid homeostasis is under circadian control. Several lines of evidence suggest that metabolic genes are directly under control of the clock machinery. In line with this transcriptomic data, it has been demonstrated that maximal fat oxidation (MFO) and the intensity at which MFO occurs is higher in the afternoon than in the morning in non-athlete male students in untrained normal-weight, athletes and obese individuals, but not in young health women. This is particularly interesting in the context of weight loss programs because timing exercise to the afternoon period may result in greater weight loss. Therefore, this study aims to evaluate whether there are diurnal variations in maximal fat oxidation in metabolic syndrome patients.