To investigate cell types, genes and mechanisms involved in the development of ARC leptin-resistance in diet-induced obesity (DIO), groups of obesity-prone C57Bl/6J mice were given ad libitum access to a high-fat diet (HFD) or low fat diet (LFD) for 3, 7 and 11 weeks. Here, LEP is linked to obesity due to melanocortin 4 receptor deficiency.