The Swedish obese subjects (SOS) study analyzed the DNA sequence variations in 11 obesity genes (ADIPOQ, BDNF, FTO, GNB3, LEP, LEPR, MC4R, NR3C1, PPARG, PPARGC1A and TNF) and found 12 SNPs in the ADIPOQ, FTO, LEP, LEPR, MC4R, PPARGC1A and TNF gene loci nominally associated with maximum weight loss. Here, FTO is linked to obesity due to melanocortin 4 receptor deficiency.