FTO and obesity due to melanocortin 4 receptor deficiency: These include the optimal nutrition provided by breastmilk, including lower protein and higher fat content compared with formula milks [66], data suggesting breastfed infants are more able to self-regulate the amount they consume [67], increased gut Bifidobacteria thought to protect against childhood obesity [68], and new data suggesting an interaction between breastmilk and the FTO allele (fat mass and obesity gene) involved in the hypothalamic regulation of appetite and energy expenditure and associated with increased BMI in adolescence [11,69].