To evaluate the effect of peripheral Crtc1 deficiency on metabolic homeostasis at the systemic and tissue levels without confounding contributions from the centrally mediated obesity, we studied Crtc1 KO mice and their wild-type littermates before 11 weeks of age, while body weights and adiposity were still comparable between the two genotype mice. The gene discussed is CRTC1; the disease is obesity due to melanocortin 4 receptor deficiency.