Vereecken 2009.

Study characteristics
Methods	Study design: cluster‐RCT Length of follow‐up from baseline: 6 months Unit of allocation: preschools Unit of analysis: child
Participants	Service type: centre‐based (preschools) Operation: not reported Country (region): Belgium (Flanders) Country income classification: high Low‐SES sample: unclear Population description: not reported Inclusion criteria: not reported Exclusion criteria: not reported Number of services randomised: 16 (8 intervention, 8 control) Number of children randomised: 1432 (867 intervention, 565 control) at baseline Characteristics Children Age: Intervention year of birth: < 2002: 41%; 2002: 28%; ≥ 2003: 31% Control year of birth: < 2002: 51%; 2002: 24%; ≥ 2003: 26%. Gender (% female): Intervention: 53% Control girls: 44% Ethnicity: not reported Parents Age (years): not reported Gender (% female): Intervention: 94% Control: 95% Ethnicity: not reported Parent/family SES: Mothers' education Intervention: low (secondary school or less): 49%; medium (Bachelor): 34%; high (Bachelor with supplementary education or Masters): 16% Control: low (secondary school or less): 49%; medium (Bachelor): 35%; high: (Bachelor with supplementary education or Masters): 16% Fathers' education Intervention: low (secondary school or less): 60%; medium (Bachelor): 22%; high (Bachelor with supplementary education or Masters): 18% Control: low (secondary school or less): 57%; medium (Bachelor): 26%; high (Bachelor with supplementary education or Masters): 17% Method of recruitment: schools were asked by mail if they would be willing to participate in an intervention study to promote healthy eating. Missing data/dropout: 46% returned a completed questionnaire at follow‐up Reasons for dropout: not reported Characteristics of dropouts: not reported
Interventions	Programme name: Beastly Healthy at School Number of conditions: 1 intervention, 1 control Intervention duration: 6 months Intervention setting: ECEC and home Intervention strategies: Health curriculum Children Education: developmental education (e.g. explanation of concepts of food triangle) Ethos and environment Children Exposure: guided and self‐guided activities based on experiential education (e.g. tasting). Healthy foods made available to children Support: role model, feedback and reinforcement by teachers Resources: cooking equipment made available to children (for use under supervision) ECEC staff Training: 2 x full‐day training sessions for principals and cafeteria staff Resources: an educational package, including an educational map for the teachers, an educative story and educational material (e.g. life‐size food education model based on the Flemish “Active Food Triangle”) was developed. Food messages and newsletters directed at the school staff were provided. A digital learning environment was provided. Support: group discussions with teachers; help on demand via email; examples of good practices. Audit and feedback: feedback provided to schools. Partnerships Families Resources: parents were provided with food messages and newsletters, and work sheets and creations by children. Activities/meetings: parent evenings and other school activities with parents Intensity of intervention: 2 d staff training; support on demand was offered via email; child curriculum (frequency and duration not reported) Intervention delivered by: research team, ECEC staff Modality: face‐to‐face, online, written Theoretical basis: The Intervention Mapping Protocol Description of control: usual care
Outcomes	Outcomes relating to child dietary intake: Water intake, fruit juice intake, sugared soft drinks intake, sugared milks intake, milk intake, fresh fruit intake, snacks intake, vegetable intake Number of participants analysed: Intervention baseline: 308‐618 Intervention follow‐up: 308‐618 Control baseline: 168‐445 Control follow‐up: 168‐445 Data collection measure: FFQ and teachers' audit Data collector: parent and teacher Validity of measures used: validated (FFQ) and not reported (teachers audit) Outcomes relating to child physical measures: not reported Outcome relating to child language and cognitive performance: not reported Outcome relating to child social/emotional measures: not reported Outcome relating to child quality of life: not reported Outcome relating to cost: not reported Outcome relating to adverse consequences: not reported
Notes	Funding source: the development of the intervention was funded by the PWO (Project‐related Scientific Research)‐funding of University College Arteveldehogeschool. Funds for the evaluation were provided by the Provincial Government East‐Flanders. Carine Vereecken is a postdoctoral researcher funded by the Research Foundation–Flanders (FWO–Flanders).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	8 control and 8 intervention schools were randomly selected and stratified on school authority, location, and size of the school. For 1 school in the intervention group, 3 departments at different locations participated. The sequence generation procedure was not described.
Allocation concealment (selection bias)	Low risk	Recruitment materials indicated there was a 50% chance that schools be randomised to the control group.
Blinding of participants and personnel (performance bias) Diet outcomes	High risk	We assumed that due to the nature of the intervention, ECEC service staff and study personnel delivering the intervention were not blind to the study allocation. The outcome is likely to be influenced by lack of blinding.
Blinding of outcome assessment (detection bias) Diet outcomes	High risk	Parents reported children's dietary intake, and data on available snacks and drinks were recorded by the teachers on a pre‐defined list. Parents and teachers were not blinded to treatment allocation and the outcome measurement is likely to be influenced by lack of blinding.
Incomplete outcome data (attrition bias) Diet outcomes	High risk	Study authors stated that "Of all children approached at baseline (n = 1432) and follow‐up (1637), respectively 884 (62%) and 761 (46%) returned a completed questionnaire; of whom 570 could be matched. Only those completed by the same respondent at both measurement occasions were kept for analyses: 308 intervention children and 168 control children." Due to the magnitude of missing data, the risk of bias was assessed as high.
Selective reporting (reporting bias)	Unclear risk	No prospective trial protocol or trial registration so it was unclear whether there was selective outcome reporting.
Recruitment bias	Unclear risk	It is unclear whether individuals were recruited to the study before or after randomisation of clusters.
Baseline imbalance	Unclear risk	Study authors state that "The control group contained considerably (borderline significantly) more boys and children from the youngest age group." Analyses of the FFQs were controlled for gender of the child and year of birth, however no other baseline data were reported (only gender, year of birth, education of mother and father, and who completed the FFQ were reported). There may be unmeasured differences between groups.
Loss of clusters	Unclear risk	Not reported
Incorrect analysis	Unclear risk	Study authors stated that "Linear mixed models (SPSS 15.0) were used to investigate the effect of the condition on changes in consumption and food policy aspects." No further information is provided. There is not enough information to assess whether an important risk of bias exists.
Contamination	Unclear risk	No evidence to make assessment
Other bias	Unclear risk	No conflict of interest statement was reported.