Body fat accrual trajectories for a sample of Asian-Canadian and Caucasian-Canadian children and youth: A longitudinal DXA-based study

Background: Body fat accrual trajectories can be used to monitor trends in body fat mass and identify potential health risks. Currently, no body fat percent (BF%) centile distance and velocity curves exist for Canadian youth. Objectives: To develop sex-specific and ethnic-specific BF% centile distance and velocity curves for White and Asian-Canadian youth. Methods: We utilized 4734 observations from 944 participants (female = 487; Asian = 532) to create sex-specific BF% velocity curves for age 10 to 18 years and sex-specific and ethnic-specific BF% percentile distance curves for ages 9 to 18 years for White and Asian children. BF% was derived from whole body DXA scans. Results: BF% centile distance curves for Asian and White girls were similar. BF% at most centiles plateaued around age 16 for Asian but not for White boys. Velocity curves for boys declined from age 11 to 13 years and then increased until age 18 years. For girls from 10 to 15 years, velocity curves converged towards the 50th centile then remained flat from 16 to 18 years. Conclusions: BF% distance and velocity centiles can be used to identify when an individual veers from an average BF% accrual trajectory. In future, these curves may be used to investigate differences in fat mass and accrual across Canada.