The study aimed to describe trajectories of free sugar (FS) intake, its main sources and the associations with socio-economic status (SES) in Portuguese children/adolescents evaluated at 4, 7, 10 and 13 years of age from Generation XXI birth-cohort. Dietary intake was assessed through 3-day food diaries (n 5268). Added sugar intake was estimated following a systematic methodology, and FS was based on the WHO de...