FAS and obesity due to melanocortin 4 receptor deficiency: In contrast, in the red skeletal muscle, we did not notice any pronounced changes in total FADS2 expression, however, induction of obesity by high-fat chow feeding significantly heightened intramuscular expression of FADS1 as well as FAS (+ 54.06% and + 34.12%, vs. the control group, respectively, p < 0.05; Fig. 8).