Although the average BMI has increased substantially across populations, so too has the variability within any given population – suggesting that an increasingly obesogenic environment may have led to preferential ‘unmasking’ of inherited susceptibility among those with highest genetic risk (Smith, 2016; Yanovski and Yanovski, 2018). For example, prior studies suggest that the impact of unhealthy diet, physical activity, and sedentary behavior on BMI are most pronounced in those with a genetic predisposition (Qi et al., 2014; Qi et al., 2012; Tyrrell et al., 2017). The ability to identify high-risk individuals from the time of birth may facilitate targeted strategies for obesity prevention with increased impact or cost-effectiveness. Given that the weight trajectories of individuals in different GPS deciles start to diverge in early childhood, such interventions may have maximal impact when employed early in life.
