LEP and type 2 diabetes mellitus: Rafee et al. [111] demonstrated the effect of apolipoprotein B insertion/deletion polymorphism and diet on serum lipids, leptin, and ghrelin levels in patients with T2DM and found that high dietary intake of carbohydrate by Del-allele carriers may have a protective role against hyperleptinemia and hyperghrelinemia by increasing the sensitivity of leptin and ghrelin receptors.