UCP1 and obesity due to melanocortin 4 receptor deficiency: WAT, the main site for the body to store lipids, stores excess energy in the form of triglycerides; whereas, BAT plays an important role in regulating energy balance and protecting against obesity by virtue of the capability for energy expenditure through thermogenesis mediated by a BAT-specific mitochondrial protein, uncoupling protein1 (UCP1) (88, 89).