OBJECTIVES: To examine the associations among UPF intake, anthropometric adiposity indicators, and obesity status in Canadian children.

DESIGN, SETTING, AND PARTICIPANTS: In the CHILD Cohort Study, one of the largest prospective, multicenter, population-based pregnancy cohorts in Canada, diet was assessed during the 3-year visit (September 2011 to June 2016), and anthropometric measurements were assessed at the 5-year visit (December 2013 to April 2018). Data analysis was performed between July 1, 2023, and June 30, 2024.

EXPOSURE: Diet intake was assessed using a semiquantitative food frequency questionnaire at 3 years of age. UPFs were identified using the NOVA classification system.

MAIN OUTCOMES AND MEASURES: Anthropometric adiposity indicators were measured at 5 years of age and used to calculate age- and sex-standardized z scores for body mass index (BMI), waist to height ratio, and subscapular and triceps skinfold thicknesses, and obesity, which was defined using BMI z score cutoffs. Multivariable-adjusted regression analyses were used to examine the associations of UPF with adiposity and obesity development, accounting for parental, birth, and early-childhood factors.