Nekitsing 2019a.

Study characteristics
Methods	Study design: cluster‐RCT (2 x 2 factorial design) Length of follow‐up from baseline: 12 weeks Unit of allocation: preschools Unit of analysis: child
Participants	Service type: centre‐based (preschools) Operation: not reported Country (region): UK (Leeds, Brighouse, and Halifax) Country income classification: high Low‐SES sample: unclear Population description: not reported Inclusion criteria: preschools were eligible to take part in the case that they were not participating in other nutrition health programmes and were able to commit to the time frame of the study (9 months). All children aged 2‐5 years attending their preschool class on the agreed test day were included. Exclusion criteria: children were excluded from the study in the case that they had any relevant food allergies, a medical condition that would prevent them from eating the test vegetable, or if their parents opted out of the study. Number of services randomised: 11 (2 Intervention 1; 3 Intervention 2; 3 Intervention 3; 3 control) Number of children randomised: 219 (62 Intervention 1; 68 Intervention 2; 55 Intervention 3; 34 control) Characteristics Children Age: Intervention 1: 38.11 months (SD 0.83) Intervention 2: 43.42 months (SD: 0.54) Intervention 3: 40.54 months (SD 0.65) Control: 41.75 months (SD 0.87) Gender (% female): Intervention 1: 51.1% Intervention 2: 52.1% Intervention 3: 64.1% Control: 37.5% Ethnicity: not reported Parents Age (years): not reported Gender (% female): not reported Ethnicity: not reported Parent/family SES: not reported Method of recruitment: 55 preschools from Leeds, Brighouse, and Halifax (West Yorkshire, UK) were sent a recruitment e‐mail in July 2016, followed by a telephone call. Missing data/dropout: lost at baseline: intervention 1: 0/62; Intervention 2: 11/68; Intervention 3: 0/55; Control: 2/34 Lost at follow‐up: intervention 1: 2/62; Intervention 2: 4/68; Intervention 3: 2/55; Control: 3/34 Reasons for dropout: children missed intake assessment days Characteristics of dropouts: no differences were found in baseline characteristics or intake of the children who were lost to follow‐up compared with those who completed the study.
Interventions	Programme name: not reported Number of conditions: 3 interventions, 1 control Intervention duration: 10 weeks Intervention setting: ECEC Intervention strategies: Intervention 1: Taste exposure Ethos and environment Children Exposure: ECEC staff offered children mooli (40‐g portions) during usual snack time once/week, for 10 weeks. Intervention 2: Nutrition education Health curriculum Children Education: staff members were instructed to teach 2 specific components of the PhunkyFood Program as often as possible during the 10‐week period. Ethos and environment ECEC staff Training: staff members were trained to deliver the existing PhunkyFoods program. Resources: ideas and inspiration for classroom carousel play activities (e.g. stories, role‐play, and games), practical food handling/preparation activities, educational displays for the classroom and parental involvement opportunities. Resources were available in both online and offline formats. Staff members were given materials to support their teaching (e.g. photo cards, posters, a floor mat, game ideas, interactive video stories, music, food preparation, tasting ideas, and drawing and colouring activities). Partnerships External provider Delivery: The PhunkyFoods team trained educators. Intervention 3: Taste Exposure + Nutrition Education Health curriculum Children Education: staff members were instructed to teach 2 specific components of the PhunkyFood Program as often as possible during the 10‐week period. Ethos and environment Children Exposure: ECEC staff offered children mooli (40‐g portions) during usual snack time once/week, for 10 weeks. ECEC staff Training: staff members were trained by the PhunkyFoods team to deliver the existing PhunkyFoods program. Resources: ideas and inspiration for classroom carousel play activities (e.g. stories, role‐play, and games), practical food handling/preparation activities, educational displays for the classroom and parental involvement opportunities. Resources were available in both online and offline formats. Staff members were given materials to support their teaching (e.g. photo cards, posters, a floor mat, game ideas, interactive video stories, music, food preparation, tasting ideas, and drawing and colouring activities). Partnerships External provider Delivery: The PhunkyFoods team trained educators. Intensity of intervention: Intervention 1: children were offered 40‐g portions of the vegetable snack once/week for 10 weeks. Invervention 2: staff trained in PhunkyFoods; 2 specific components of the PhunkyFood Program delivered to children as often as possible during the 10‐week period Intervention 3: children were offered 40‐g portions of the vegetable snack once a week for 10 weeks; staff trained in PhunkyFoods; 2 specific components of the PhunkyFood Program delivered to children as often as possible during the 10‐week period. Intervention delivered by: Intervention 1: research team, ECEC staff Intervention 2: ECEC staff, healthcare staff Intervention 3: research team, ECEC staff, healthcare staff Modality: Intervention 1: face‐to‐face Intervention 2: face‐to‐face, online, written Intervention 3: face‐to‐face, online, written Theoretical basis: not reported Description of control: usual care
Outcomes	Outcomes relating to child dietary intake: Intake of test vegetable (mooli) Number of participants analysed: Intervention 1 baseline: 32‐47 Intervention 1 follow‐up: 44‐47 Intervention 2 baseline: 31‐38 Intervention 2 follow‐up: 38 Intervention 3 baseline: 25‐29 Intervention 3 follow‐up: 25‐39 Control baseline: 12‐16 Control follow‐up: 12‐16 Data collection measure: each vegetable portion was weighed before and after each snack time using a digital scale Data collector: researcher Validity of measures used: not reported 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: White Rose Doctoral Training Centre (WRDTC) Economic and Social Research Council (ESRC) Collaborative Award. The collaborative partner is Purely Nutrition Ltd. Contribution in kind, which includes storybooks and photo cards, were received from Purely Nutrition Ltd.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Preschools were stratified by size and randomly assigned to one of 4 intervention conditions using an online list generator (https://www.random.org/lists).
Allocation concealment (selection bias)	Low risk	Preschool managers were not informed of their condition allocation until all preschools were recruited (after consent) and randomised. It was possible to conceal condition allocation between clusters but not within a cluster.
Blinding of participants and personnel (performance bias) Diet outcomes	High risk	Teachers were aware of allocation and could have encouraged students to eat or try more of the vegetable on testing days.
Blinding of outcome assessment (detection bias) Diet outcomes	Low risk	Blinding not reported, however vegetable portions were measured before and after intake to the nearest 0.01 g to determine consumption. The outcome measurement is not likely to be influenced by lack of blinding.
Incomplete outcome data (attrition bias) Diet outcomes	High risk	Data were available for 140 (64%) children allocated to a treatment group at follow‐up, with follow‐up rates between 47%‐76% across the 4 groups. Study authors stated that "due to the nature of the study design there was a high rate of missing data over time for the complete set of intake data, including follow‐ups (36%). As a result of this, there was a substantially smaller sample size in the control condition" Due to the magnitude of missing data and difference in the proportions of participants followed up between groups, the risk of bias was assessed as high.
Selective reporting (reporting bias)	Unclear risk	Trial registered with primary outcome reported as described. Secondary outcome measure of intake of usual vegetables, however this outcome was not reported in the study.
Recruitment bias	Low risk	Individuals and schools were recruited before randomisation of clusters. Study authors state that "Preschool managers were not informed of their condition allocation until all preschools were recruited (after consent) and randomized. It was possible to conceal condition allocation between clusters but not within a cluster."
Baseline imbalance	Low risk	No baseline differences noted between groups with regards to sex distribution or mean BMI z‐score, but there were differences in mean age. Age was controlled for in analyses.
Loss of clusters	Low risk	No loss of clusters
Incorrect analysis	Low risk	Study authors stated that "Because children were recruited using a cluster design, it was important to account for the influence of cluster assignment. In addition, for repeated measures, each data point was clustered within child. Therefore all the models described below corrected for this using the complex samples procedure within SPSS version 24 to incorporate the contribution of these variance components to the data."
Contamination	Unclear risk	No evidence to make assessment
Other bias	Unclear risk	Deviation from methods noted. Study authors stated that "However, given that many children did not eat mooli at baseline, the data were significantly skewed and not suited to simple parametric analysis. Therefore, children were categorized according to their eating pattern at postintervention, Follow‐up 1 and Follow‐up 2 (noneater, eater) and these are shown in Table 2." There is insufficient information to assess whether an important risk of bias exists. A commercial organisation provided in‐kind support.