Exploring intervention components in association with changes in preschool children’s vegetable intake: the BRA-study

OBJECTIVE: The present study aimed to explore kindergarten staffs’ perceived usefulness of intervention components in association with changes in children’s vegetable intake and vegetables served in the kindergarten. Assessment of the perceived usefulness of intervention components consisted of a paper-based questionnaire for the kindergarten staff assessing usefulness of posters, supplementary material and 1-day inspirational course. Children’s vegetable intake in the kindergarten was assessed by direct observation, while vegetables served was assessed by a 5-day weighted vegetable diary. RESULTS: Seventy-three kindergartens in two counties in Norway participated (response rate 15%) and parental consent was obtained for 633 children 3–5 years of age at baseline (response rate 39%). Mixed effect models indicated a tendency that posters were associated with increased child vegetable intake (P = 0.062). Surprisingly, a low degree of perceived usefulness of supplementary material was associated with the largest increase in child vegetable intake (P = 0.020). No significant associations between perceived usefulness of intervention components and vegetables served in the kindergarten were found. This study indicated a tendency that posters were associated with increased child vegetable intake; however, this may also be due to synergies between multiple intervention components. Trial registration International Standard Randomized Controlled Trials ISRCTN51962956 (http://www.isrctn.com/ISRCTN51962956). Registered 21 June 2016 (retrospectively registered). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13104-021-05629-1.