Play & Grow: prospective observational cohort of toddlers to inform obesity prevention, Columbus, Ohio, USA.

PURPOSE: Obesity prevention is increasingly focused on early childhood, but toddlers have not been well-studied, and children born preterm are frequently excluded. The Play & Grow Cohort was established to investigate child growth in relation to parent-child interactions in mealtime and non-mealtime settings. PARTICIPANTS: Between December 2017 and May 2019, 300 toddlers and primary caregivers were recruited from records of a large paediatric care provider in Columbus, Ohio, USA. This report describes recruitment of the cohort and outlines the data collection protocols for two toddler and two preschool-age visits. The first study visit coincided with enrolment and occurred when children (57% boys) were a mean (SD) calendar age of 18.2 (0.7) months. FINDINGS TO DATE: Children in the cohort are diverse relative to gestational age at birth (16%, 28-31 completed weeks' gestation; 21%, 32-36 weeks' gestation; 63%, ≥37 weeks' gestation) and race/ethnicity (8%, Hispanic; 35%, non-Hispanic black; 46%, non-Hispanic white). Caregivers enrolled in the cohort are primarily the child's biological mother (93%) and are diverse in age (range 18-54 years), education (23%, high school or less; 20% graduate degree) and annual household income (27%,