GIP and obesity due to melanocortin 4 receptor deficiency: Besides GIP receptor expression on adipocytes (Yip et al., 1998), other indications for a link between GIP and obesity include the findings of increased circulating GIP levels in both obese individuals (Calanna et al., 2013) and subjects given a high‐fat diet (HFD) (Brøns et al., 2009).