Further simple effects analysis showed the following: under normal weight status (fixed obesity factor), a significant difference was observed in Sirt1 mRNA levels between the CSG and CEG [F(1,40) = 48.660; partial η2 = 0.619; P < 0.001], with the CEG exhibiting significantly higher Sirt1 mRNA levels than the CSG (I-J = 1.805; P < 0.001). This evidence concerns the gene SIRT1 and obesity due to melanocortin 4 receptor deficiency.