Objectives: To investigate the associations of lifestyle behaviours with indicators of cardiometabolic health and body composition and whether the associations vary by genetic susceptibility in children and adolescents.

Methods: We will use both genotype and phenotype data from the “Avon Longitudinal Study of Parents and Children” birth cohort of European children and adolescents. Genetic risk for unhealthy levels of cardiometabolic risk markers and body composition will be calculated based on the established trait-specific genetic variants. We will use accelerometer data (collected at average ages 11, 13, 15 and 24 years) to derive sedentary time, light physical activity (PA) and moderate-to-vigorous PA, and 4 sets of questionnaire data to quantify 3 sedentary activities and 1 PA type.

Conclusions: Findings from the proposed research will indicate the roles of PA and sedentary time in enhancing cardiometabolic health and body composition, and whether such roles differ by genetic susceptibility in children and adolescents of European ancestry.