Fruit and vegetable (F&V) intake among children in western countries is below recommended levels. To increase F&V consumption in children (3-6 years), a novel method is proposed based on the concepts of repetitive taste exposure, role models, and non-food rewards guided by the dietary advice: "Eat the rainbow: go for color!" The aim is to determine the effect of this intervention to stimulate the consumption of color on the willingness to try different fruits and vegetables in 210 children aged 3-7 years old

Rationale: A diet rich in fruits and vegetables (F&V) has many health benefits in early childhood. Nevertheless, F&V intake among children in western countries is below recommended levels. To increase F&V consumption in children (3-6 years), a novel method is proposed based on the concepts of repetitive taste exposure, role models, and non-food rewards guided by the dietary advice: "Eat the rainbow: go for color!" Objective: To determine the effect of a modeling- and reward-based intervention to stimulate the consumption of color on the willingness to try different fruits and vegetables in children aged 3-7 years old.

Study design: The study follows a parallel study design. All participants will participate in a baseline session after which they are exposed to a color intervention, a reference intervention, or a control session. Each of the three conditions will be randomly assigned to one of the groups (classrooms) in the participating preschools.

Intervention: The color intervention group listens to a story of Miffy who eats vegetables and fruits in all colors of the rainbow. Afterward, subjects are invited to taste different F&Vs. They are rewarded with a sticker for each color they have eaten. The reference intervention group does not listen to a story and is given a sticker for each type of F&V they have eaten. In the control session, the children are invited to eat F&Vs without any introduction story or reward.

Main study parameters/endpoints: The number of pieces of F&Vs and the number of different types of F&Vs selected, tried, and consumed by the children.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The study is non-therapeutic to the subjects. No immediate benefits for the subjects are expected from participation in this study, and the risk associated with participation can be considered negligible. In terms of time, the subject's burden is as follows: 30 minutes for the questionnaires prior to the intervention sessions for the caregiver and 15 minutes for the child; 30 minutes for each of the two intervention sessions, however, this coincides with the regular morning break of the children and therefore does not cost extra time, and lastly, 15 minutes for the questionnaire after the intervention sessions for both the child and the caregiver. In total, the time burden amounts to 45 minutes for the participating caregiver and 1 hour and 30 minutes for the participating child.

Inclusion Criteria:

• Children in early childhood education and in the first year of primary school within the age range of 3-7.
• Both caregivers as well as the child are willing to comply to the study procedure;

Exclusion Criteria:

• Children who have any allergies or intolerances to the fruits and vegetables used in the study;
• Not willing to eat the test foods because of eating habits or beliefs as indicated by parent or caregiver;