FOXO3 and obesity due to melanocortin 4 receptor deficiency: Hasan [55] reported that increased expressions of FOXO3, Atrogin-1/MAFbx, and MuRF-1 and a decreased expression of PGC-1α, which plays a role as a mitochondrial biogenesis regulator in the skeletal muscle of the HFD-induced obesity rats, was attributed to insulin resistance of the muscles, which was consistent with a report by Abrigo et al. [56] and our study.