Background Early childhood represents a critical period for the establishment of long-lasting healthy dietary habits. Limited knowledge exists on how to successfully increase vegetable consumption among preschool children. The overall aim of the present study was to improve vegetable intake among preschool children in a kindergarten-based randomized controlled trial. Methods The target group was preschool children born in 2010 and 2011, attending public or private kindergartens in two counties in Norway. Data about child intake of vegetables were collected by three methods. First, parents filled in a web-based questionnaire of the child’s vegetable intake. Second, among a subsample, trained researchers observed children’s vegetable intake in the kindergarten. Thirdly, a parental web-based 24-h recall assessing the child’s vegetable intake was filled in. For allocation of kindergartens to intervention and control groups, a stratified block randomization was used. Multiple intervention components were implemented from September 2015 to February 2016 and components focused at influencing the four determinants availability, accessibility, encouragement and role modelling. The effect of the intervention from baseline (spring 2015) to follow-up 1 (spring 2016) was assessed by mixed-model analysis taking the clustering effect of kindergartens into account. Results Parental consent was obtained for 38.8% of the children (633 out of 1631 eligible children). Based on the observational data in the kindergarten setting (n 218 in the control group and n 217 in the intervention group), a tendency to a small positive effect was seen as a mean difference of 13.3 g vegetables/day (95% CI: − 0.2, 26.9) ( P = 0.054) was observed. No significant overall effects were found for the total daily vegetable intake or for the parental reported frequency or variety in vegetable intake. Conclusions Based on the observational data in the kindergarten setting, a tendency to a small positive effect was seen with a mean difference of about 13 g vegetables/day, while no other effects on child vegetable intake were found. Additionally, further research to understand the best strategies to involve parents in dietary interventions studies is warranted. Trial registration International Standard Randomised Controlled Trials ISRCTN51962956 . Registered 21 June 2016 (retrospectively registered). Electronic supplementary material The online version of this article (10.1186/s12889-019-7436-3) contains supplementary material, which is available to authorized users.

This age group has so far been understudied and there is a need for comparable studies. Our findings highlight the importance of targeting the physical home environment of pre-school children in future interventions as there are important modifiable factors that both promote and hinder vegetable consumption in this environment.

Aim:The aim of the present study was to explore the associations between the economic, political, sociocultural and physical environments in kindergartens, along with the frequency and variety of vegetables served, and the amount of vegetables eaten. Method: The BRA Study collected data through two paper-based questionnaires answered by the kindergarten leader and pedagogical leader of each selected kindergarten, and a five-day vegetable diary from kindergartens (n = 73) in Vestfold and Buskerud Counties, Norway. The questionnaires assessed environmental factors, and the frequency and variety of vegetables served. The non-parametric Mann-Whitney U and Kruskal-Wallis tests were used to explore the associations between factors in the kindergarten environments and vegetables served and eaten. Results: Kindergartens that included expenditures for food and beverages in the parental fees served a larger variety of vegetables (p = 0.046). A higher frequency of served vegetables (p = 0.014) and a larger amount (p = 0.027) of vegetables eaten were found in kindergartens where parents paid a monthly fee of 251 NOK or more. Similarly, the amount of vegetables eaten was higher (p = 0.017) in kindergartens where the employees paid a monthly fee to eat at work. Furthermore, a larger amount (p = 0.046) of vegetables was eaten in kindergartens that had written guidelines for food and beverages that were offered. Conclusions: This study indicates that the economic environment in a kindergarten seems to be positively associated with the vegetables served and eaten there. This is of high relevance for public health policy as vegetable consumption is an important factor in reducing the risk of non-communicable diseases.

Objective:The aim of the current study was to evaluate the effect on frequency, variety and amount of vegetables served and staff’s food-related practices in the multicomponent BRA intervention.Design:Cluster randomised controlled trial, conducted between Spring 2015 and Spring 2016. For allocation of the kindergartens, a stratified block randomisation was used. Data were collected in three ways: (i) a questionnaire for pedagogical leaders assessing the variety and frequency of vegetables served, including staff’s food-related practices assumed to be related to vegetable intake; (ii) a questionnaire for kindergarten assistants assessing staff’s food-related practices; (iii) a 5-d weighted vegetable diary assessing amount of vegetables served in a department.Setting:The target group for this study was public and private kindergartens in the counties of Vestfold and Buskerud, Norway.Participants:A total of seventy-three kindergartens participated.Results:At follow-up I, the amount of vegetables served increased by approximately 20 g per person per day (P = 0·002), and the variety in served vegetables increased by one-and-a-half kind per month (P = 0·014) in the intervention group compared to the control group. No effects on the frequency of vegetables served or on staff’s food-related practices were found.Conclusions:The BRA intervention was successful in increasing the amount and variety of vegetables served within intervention kindergartens. Further research is needed to understand the mechanisms that can affect the staff’s food-related practices.

The home environment is the first environment to shape childhood dietary habits and food preferences, hence greater understanding of home environmental factors associated with vegetable consumption among young children is needed. The objective has been to examine questionnaire items developed to measure the sociocultural home environment of children focusing on vegetables and to assess the psychometric properties of the resulting factors. Further, to explore associations between the environmental factors and vegetable consumption among Norwegian 3-5 year olds. Parents (n 633) were invited to participate and filled in a questionnaire assessing the child's vegetable intake and factors potentially influencing this, along with a 24-h recall of their child's fruit and vegetable intake. Children's fruit and vegetable intakes at two meals in one day in the kindergarten were observed by researchers. Principal components analysis was used to examine items assessing the sociocultural home environment. Encouragement items resulted in factors labelled "reactive encouragement", "child involvement" and "reward". Modelling items resulted in the factors labelled "active role model" and "practical role model". Items assessing negative parental attitudes resulted in the factor labelled "negative parental attitudes" and items assessing family pressure/demand resulted in the factor labelled "family demand". The psychometric properties of the factors were for most satisfactory. Linear regression of the associations between vegetable intake and the factors showed, as expected, generally positive associations with "child involvement", "practical role model" and "family demand", and negative associations with "negative parental attitudes" and "reward". Unexpectedly, "reactive encouragement" was negatively associated with vegetable consumption. In conclusion, associations between sociocultural home environmental factors and children's vegetable consumption showed both expected and unexpected associations some of which differed by maternal education - pointing to a need for further comparable studies.