At age 9.9 (± 0.33) y, all offspring were invited to attend a research clinic for a 3-h assessment, which included a session of anthropometric measurements. Height was measured with shoes and socks removed using a Harpenden stadiometer (Holtain Ltd). Weight was measured using a Tanita TBF 305 body fat analyser and weighing scales (Tanita UK Ltd, http://www.tanita.co.uk). Whole-body fat mass was measured using dual-energy X-ray absorptiometry (DXA; Lunar Prodigy, GE Medical Systems, http://www.gehealthcare.com/) and performed by trained fieldworkers, The scans were visually inspected and realigned where necessary. We performed repeated DXA measurements for 122 children on the same day, and the repeatability coefficient (twice the standard deviation of the difference between measurement occasions) [15] for body fat mass was 0.5 kg.
