SIRT1 and obesity due to melanocortin 4 receptor deficiency: Unexpectedly, elevated risk to having a greater BMI was related to a higher copy number of the most common haplotype (alleles A of rs7895833, G of rs1467568, and G of rs497849) among subjects with low VE intake [161], suggesting the capacity of VE to modify the association between SIRT1 variants and obesity.