UCP1 and obesity due to melanocortin 4 receptor deficiency: Our data demonstrating reductions in oxygen consumption at TN, but not at RT with CPF, are similar to observations in UCP1 null mice, which also only develop HFD-induced obesity when housed at TN; an effect attributed to impairments in BAT diet-induced thermogenesis7, We found that in HFD-fed mice housed at TN, CPF reduced Ucp1 mRNA and protein expression (Fig. 4a and b) and increased the size and number of lipid droplets (Fig. 4c) within the BAT.