The Combination of Physical Activity and Sedentary Behaviors Modifies the Genetic Predisposition to Obesity.

Objective: This study aimed to investigate whether the association between a validated genetic profile risk score for BMI (GPRS-BMI) (based on 93 single-nucleotide polymorphisms) and phenotypic obesity (BMI) was modified by the combined categories of physical activity (PA) and sedentary behaviors in a large population-based study.

Methods: This study included cross-sectional baseline data from 338,216 white European adult men and women aged 37 to 73 years. Interaction effects of GPRS-BMI with the combined categories of PA and sedentary behaviors on BMI were investigated.

Results: There was a significant interaction between GPRS-BMI and the combined categories of objectively measured PA and total sedentary behavior (P   =  3.5 × 10 ); among physically inactive and highly sedentary individuals, BMI was higher by 0.60 kg/m per 1-SD increase in GPRS-obesity (P  =  8.9 × 10 ), whereas the relevant BMI difference was 38% lower among physically active individuals and those with low sedentary time (β: 0.37 kg/m ; P  =  2.3 × 10 ). A similar pattern was observed for the combined categories of objective PA and TV viewing (inactive/high TV viewing β: 0.60 vs. active/low TV viewing β: 0.40 kg/m ; P   =  2.9 × 10 ).

Conclusions: This study provides evidence that combined categories of PA and sedentary behaviors modify the extent to which genetic predisposition to obesity results in higher BMI.