Shc-depleted (ShcKO) mice resist obesity on chow diets and on high-fat diets and are more insulin sensitive and glucose tolerant at young and old age (Berniakovich et al., 2008; Ranieri et al., 2010; Tomilov et al., 2011). This evidence concerns the gene SHC1 and obesity due to melanocortin 4 receptor deficiency.