We observed similar results (figure 2a) such that both when UCP1 KO mice, in this case on an FVB/N background, were fed a chow diet (not shown here) or a high-fat cafeteria diet, the KO mice were protected against obesity, as was also observed on a C57Bl/6 background [15,18]. This evidence concerns the gene UCP1 and obesity due to melanocortin 4 receptor deficiency.