For example, saturated FAs (SFAs), whose concentrations are increased in obesity or following a high-fat diet (HFD), can induce beta-cell production of interleukin 1 (IL-1) [38,39,40], a cytokine able to increase the local expression of proinflammatory molecules, leading to local inflammation, apoptosis, and impaired insulin secretion [41]. This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.