UCP2 and obesity due to melanocortin 4 receptor deficiency: However, few studies assess the changes in PGC-1α and UCP-2 post-operatively, and due to the important role of mitochondrial dysfunction in obesity pathogenesis or lack of success in non-surgical weight loss programs, the aim of this study was to evaluate the changes in serum PGC-1α and UCP-2 simultaneously with the changes in weight and body composition, insulin resistance, blood lipids, insulin, and glycemic control, liver enzymes, and their relationships.