For this reason, we have used here a combination of molecular, cellular and whole‐animal approaches to study the influence of diet‐induced obesity on PG insulin management, and on the gene expression profile of the components of the GH/IGF1/insulin systems at the PG level, as well as the direct role of these hormones (insulin and IGF‐I) in normal and tumoral prostate cells. The gene discussed is GH1; the disease is obesity due to melanocortin 4 receptor deficiency.