A study that included 49 mothers and their 111 children aged 2.5–26 years demonstrated that offspring born after maternal biliopancreatic diversion bariatric surgery had a markedly lower prevalence of macrosomia, a reduced risk of severe obesity, greater insulin sensitivity and improved lipid profiles in adolescence, compared with their siblings born prior to the surgery [29]. This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.