This obesity-risk variant (odds ratio for obesity of 1.305 per copy) is unique in that, even though it has a BMI-increasing effect size greater than any other known common obesity-risk variant (1.36–1.45 kg/m2 CREBRFR457Q versus only 0.37 kg/m2 for the FTO locus), it is paradoxically associated with relative protection from diabetes (odds ratio for diabetes of 0.586 after controlling for BMI) and other metabolic complications of obesity [7]. This evidence concerns the gene FTO and obesity due to melanocortin 4 receptor deficiency.