Figure 3: Interaction between BDNF genotype and n-3 : n-6 PUFA ratio on waist circumference in the BPRHS. Lozenges represent the major allele GG homozygotes ( in men; in women) and triangles the minor allele A carriers (AA homozygotes and GA heterozygotes combined together, in men; in women). Predicted waist circumference values for all subjects were plotted against their n-3 : n-6 PUFA ratio. Waist values were calculated based on a regression model containing n-3 : n-6 PUFA ratio, BDNF genotypes, and the potential confounders including age, smoking status, drinking status, sex, education, medication use for depression, physical activity, total energy, and population admixture.