Process evaluation of a cluster randomised controlled trial of a school-based fruit and vegetable intervention: Project Tomato

Objective: The present analysis evaluates the overall appreciation and implementation of an intervention, Project Tomato, designed to maintain fruit and vegetable intake in children aged 8-9 years. Design: A random sample of fifty-four English primary schools (658 children) were randomised to either the intervention group or the control. The intervention group received a multi-component programme delivered in school by teachers and items sent home for parents/children. Dietary measurements were collected at baseline and follow-up. The intervention participants completed questionnaires on the intervention materials, to identify implementation and appreciation of the intervention, and other environmental mechanisms. Setting: Fifty-four primary schools were randomly selected, with twenty-seven schools allocated to the intervention group. Subjects: A total of 311 children received the intervention. Results: Implementation of the intervention was low, 21.3% of school items and 56.0% of home items were implemented. The intervention materials were well received by teachers, parents and children. Other mechanisms that may affect fruit and vegetable intake were explored. Children who ate their main meal with their parents 3-7 nights/week on average consumed 37.6 (95% CI 9.8, 65.4) g more fruit and vegetables than children who ate with their parents 0-2 times/week. Conclusions: Implementation of the trial components was poor. However, the results identified the importance of parental environment and mealtime structure on children's fruit and vegetable intake.