(A) Triglyceride composition from WAT from WT and SIRT4 KO fed and fasted mice (n=3 mice per genotype, per condition). (B–C) Skeletal Muscle (quadriceps) phospholipid and triglyceride composition from WT and SIRT4 KO fed and fasted mice (n=3 mice per genotype, per condition). (D–E) Exercise tolerance assays were performed on WT and SIRT4 KO mice (n=11–14 per genotype). (F–G) RER in WT and SIRT4 KO mice during exercise (F) and recovery (G) (n=11–14). (H–J) De novo lipogenesis in vivo was measured by determining incorporation of deuterated water into palmitate in WAT (H), liver (I), and plasma (J) (n=6 per genotype). In each panel, data represent mean ± SEM. (*) p < 0.05; (**) p < 0.01, (***) p < 0.001. See also Figure S3.