INS and obesity due to melanocortin 4 receptor deficiency: Male C57BL/6 mice were fed a high‐fat diet (60% fat) for 20 weeks to induce obesity. Insulin tolerance, CRP levels, and macrophage inflammatory activity (measured by SUVmax on 18F‐FDG PET/CT) were assessed. Flow cytometry, histology, and molecular analyses were performed on harvested visceral adipose tissue (VAT) after sacrifice.