Thus, taking together the morphological changes and increased mitochondrial protein levels seen in the present study and the previously observed increased mRNA levels for Adrb3, Ppara, Ppargc1a, and Ucp1[11], these results strongly support the idea that a browning reaction occurs in the WAT of BMSO-fed mice and that this might contribute to the observed resistance to diet-induced obesity and the favorable effects on insulin sensitivity [17]–[19]. This evidence concerns the gene UCP1 and obesity due to melanocortin 4 receptor deficiency.