Morris 2018.

Study characteristics
Methods	Study design: cluster‐RCT Length of follow‐up from baseline: 3 months Unit of allocation: kindergartens Unit of analysis: child
Participants	Service type: centre‐based (Early Childhood Management Services‐run kindergartens) Operation: not reported Country (region): Australia (Melbourne) Country income classification: high Low‐SES sample: no Population description: not reported Inclusion criteria: sessional kindergartens Exclusion criteria: not reported Number of services randomised: 25 teachers (14 intervention, 11 control) Number of children randomised: 300 (168 intervention, 132 control) Characteristics Children Age: Intervention: 4.76 years (SD: 0.36) Control: 4.68 years (SD: 0.37) Gender (% female): not reported Ethnicity: Intervention: born in Australia: 90.6%; not born in Australia: 9.4% Control: born in Australia: 94.6%; not born in Australia: 5.4% Parents Age (years): Intervention: mother: 35.15 (SD 4.92); father: 38.32 (SD 5.69) Control: 35.32 (SD 4.93); fathers: 37.29 (5.31) Gender (% female): not reported Ethnicity: Mothers: Intervention: born in Australia: 72.4% (intervention); not born in Australia: 27.6% Control: born in Australia: 70.3%; not born in Australia: 29.7% Fathers: Intervention: born in Australia: 74.8%; not born in Australia: 24.4% Control: born in Australia: 61.8%; not born in Australia: 36.4% Parent/family SES: Combined family income Intervention: low < AUD 25,000‐65,000: 28.1%; medium AUD 65,001‐105,000: 31.4%; ; high AUD 105,001‐145,000: 40.5% Control: low < AUD 25,000‐65,000: 27.4%; medium AUD 65,001‐105,000: 29.2%; high AUD 105,001‐145,000: 43.4% Mothers' education Intervention: high school only: intervention 29.5%; vocation/technical: intervention 13.1%; all university: 49.2% Control: high school only: 33.7%; vocation/technical: 5.8%; all university: 51.9% Fathers' education Intervention: high school only: 35.5%; vocation/technical: 21.5%; all university: 37.2% Control: high school only: 40.6%; vocation/technical: 20.8%; all university: 34.6% Method of recruitment: all eligible parents of children were personally invited to participate by the researchers at the kindergarten service. Parents initiated their child’s participation. Missing data/dropout: not reported Reasons for dropout: not reported Characteristics of dropouts: not reported
Interventions	Programme name: not reported Number of conditions: 1 intervention, 1 control Intervention duration: 8 weeks Intervention setting: ECEC Intervention strategies: Health curriculum Children Education: teachers implemented their planned play‐based learning experiences over a period of 8 weeks. Ethos and environment ECEC staff Training: session 1 ‐ All teachers (intervention and control) attended a professional learning session (delivered by research group) to explain the project. They also considered a case study detailing a preschool‐aged child’s interest in digital media and popular culture characters. Waitlist control teachers then departed the session. The remaining intervention group teachers brainstormed a series of play‐based learning experiences, connecting well‐being and sustainability knowledge to the case study‐child’s interests. Session 2 ‐ Intervention teachers only attended a second professional learning session. The session started with a seminar detailing content knowledge about well‐being and sustainability appropriate for young children (topics were physical activity, healthy eating, healthy lifestyles, and natural environments). This was followed by a discussion and workshop of teacher's play‐based learning experience. Resources: teachers were provided with: professional learning materials, namely a Pedagogical Communication Strategy and details of different play types (e.g. open‐ended, modelled and purposefully framed play) used to build children’s knowledge about well‐being and sustainability; a visual‐arts diary to record their planned play‐based learning experiences and observation/assessment of the implemented experiences using their normal methods; and, a book detailing the use of the 3 play‐types in the provision of early childhood environmental education. Teachers had access to a purpose‐designed website containing copies of all project materials. Support: teachers were provided with an implementation protocol and the phone and email contact details of researchers. Intensity of intervention: 2 x professional learning sessions; at least 2 x play based learning experiences implemented each week for children Intervention delivered by: research team, ECEC staff Modality: face‐to‐face, online, written Theoretical basis: Funds of Knowledge Description of control: wait‐list control, plus teachers attended 1 professional learning session
Outcomes	Outcomes relating to child dietary intake: Total unhealthy food (e.g. packaged snack foods, confectionary and cakes) intake, fruit and vegetable intake, unsweetened drinks intake, sweetened drink intake, vegetable intake, usual vegetables intake, fruit intake, packaged snacks intake Number of participants analysed: Intervention baseline: 89‐102 Intervention follow‐up: 89‐102 Control baseline: 81‐101 Control follow‐up: 81‐101 Data collection measure: Eating and Physical Activity questionnaire (EPAQ) Data collector: parent Validity of measures used: validated 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: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	An uninvolved researcher used a computer algorithm to complete random permutations of 1 for intervention and 2 for waitlist control
Allocation concealment (selection bias)	Low risk	While the group allocation could not be concealed from the ECEC teachers, it was concealed from the parents and data collection researchers.
Blinding of participants and personnel (performance bias) Diet outcomes	High risk	No blinding of teachers, and although allocation was concealed from the parents, it is likely that the blinding could have been broken. 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. Although the group allocation was concealed from parents, it is likely that the blinding could have been broken and the outcome measurement is likely to be influenced by lack of blinding.
Incomplete outcome data (attrition bias) Diet outcomes	Unclear risk	Study authors stated that "Almost three quarters of the parents (n = 187; 72.2 per cent) returned EPAQ surveys at all three timepoints, and 14 per cent did not return any EPAQ surveys." No information is provided as to whether missing data and reasons for missing data were similar across groups. Study authors stated that "Multiple imputation of the EPAQ data was used to address missing values." Risk of attrition bias is unclear.
Selective reporting (reporting bias)	Unclear risk	The protocol states that the Eating and Physical Activity Questionnaire will be used to measure dietary outcomes, however the outcomes of interest are not specifically reported.
Recruitment bias	Low risk	Group allocation was concealed from parents so it is likely that individuals consented to the study without knowing allocation.
Baseline imbalance	Low risk	Study authors state that "No significant differences were seen between age, gender, country of birth or BMI in the intervention group and waitlist control group." ANOVA calculations found only one significant demographic characteristic difference between the means of fathers' height in each group.
Loss of clusters	Unclear risk	Not reported
Incorrect analysis	High risk	There was no accounting for clustering of children within kindergartens.
Contamination	Unclear risk	No evidence to make assessment
Other bias	High risk	No funding statement was provided. No conflict of interest statement was reported.