The power of each of the SNPs to discriminate between normal weight and obese individuals [i.e. the receiver-operating characteristic curves (ROCAUC)] was compared against the discriminative power of the GBS as the criterion variable (Table 4). The crude ROCAUC for the GBS was 0.5752 (Fig. 3) (P < 0.0001). This compared with a ROCAUC of 0.5881 (P < 0.0001) when all eight SNPs were entered simultaneously into the ROC model. The combination of all SNPs was a significantly more powerful discriminator than any single SNP, with or without adjustment for age and sex (P < 0.05). The FTO variant was the most discriminative of the individual SNPs (crude ROCAUC = 0.5435; P < 0.0001), with the crude ROCAUCs ranging from 0.5087 to 0.5348 for the remaining SNPs.
