The interactions between APOA2 and saturated fat for obesity may be mediated via modulation of plasma ghrelin and expansion of knowledge of APOA2 and obesity to include modulation of specific behaviours and hormonal mediators not only broadens understanding of gene-diet interactions, but also facilitates the pragmatic, future goal of developing dietary guidelines based on genotype [22]. Here, APOA2 is linked to obesity due to melanocortin 4 receptor deficiency.