INS and obesity due to melanocortin 4 receptor deficiency: -Inverse association with intra-abdominal WAT and obesity (111, 172, 222–224).-Inverse association with T2D, mediated by visceral fat content (103, 110, 225, 226).-Decreases with weight gain (227).-Increases with weight loss in obese men and women (111, 228–232).-Promotes WAT flexibility in women, contributing to improved insulin sensitivity (233).