CR has also been shown to upregulate SIRT1 activity [151] as well as increase peroxisome proliferator activated receptor (PPAR)-γ coactivator-1α (PGC-1α) activity, which was associated with improved mitochondrial functioning as well as improvements in oxidative stress, insulin resistance, metabolic rate, and body composition [152]. This evidence concerns the gene SIRT1 and Insulin resistance.