UCP3 and obesity due to melanocortin 4 receptor deficiency: In this regard, a procyanidin extract of cocoa liquor (total polyphenols: 69.8% w/w) prevented hyperglycemia and obesity in mice fed with a HF diet by phosphorylation of AMPK and enhanced expression of PGC-1α, with subsequent up-regulation of UCP1 in BAT, uncoupling protein 2 (UCP2) in WAT and uncoupling protein 3 (UCP3) in SKM [146].