Conversely, ghrelin levels decrease in response to rising BMI and obesity, and increased levels of glucose, insulin, lipids, leptin, GH, somatostatin, peptide YY, urocortin-1 and gastrin (Tschöp et al. 2001, Shiiya et al. 2002, Murdolo et al. 2003, Korbonits et al. 2004, Soriano-Guillén et al. 2004, Garcia et al. 2006, Ingelsson et al. 2008, Rau et al. 2013). This evidence concerns the gene GHRL and obesity due to melanocortin 4 receptor deficiency.