Consistent with the meta-analysis of BMI, PA attenuated the effect of the FTO risk allele on the odds of obesity (p interaction = 0.001) and on the odds of overweight (p interaction = 0.02) (Table 2; Figures S2 and S3). The odds of obesity for the FTO risk allele were 27% smaller (odds ratio [OR] = 1.22 versus 1.30, respectively) and the odds of overweight were 26% smaller (OR = 1.14 versus 1.19, respectively) in physically active individuals than in inactive individuals (Table 2). Similar to the results for BMI, there seemed to be a more pronounced FTO×PA interaction effect in North American populations than in Europeans: the risk-attenuating effect of PA was more than double in North Americans compared to Europeans (Table 2; Figures S2 and S3). The differences in the interaction effect between North Americans and Europeans on the odds of obesity and overweight were, however, not significant (p difference = 0.2 for both obesity and overweight).
