Analysing 18,014 Danish individuals, we failed to demonstrate a correlation between the INSIG2 rs7566605 C-allele and the PFKP rs6602024 A-allele and excessive body fat accumulation both in case-control studies of overweight and obesity, and when analysing quantitative obesity-related traits. The gene discussed is INSIG2; the disease is obesity due to melanocortin 4 receptor deficiency.