de Wild 2015a

Methods	Study design: Randomised controlled trial Funding: "European Community’s Seventh Framework Programme (FP7/2007‐2013) under the Grant agreement No. 245012‐HabEat."
Participants	Description: Preschool‐aged children recruited from 3 daycare centres in Wageningen, the Netherlands N (Randomised): 75 children Age: 1.9‐5.9 years (mean = 3.7 years) % Female: 50% SES and ethnicity: Not specified Inclusion/exclusion criteria: No explicit inclusion/exclusion criteria. “Participants were screened for food allergies and health problems (as reported by the parents)” Recruitment: “Parents with children in the targeted age range received an information letter and an invitation to register their child(ren) for participation via the day‐cares. Participation was voluntary and parents and day care‐centres were thoroughly informed about the study.” Recruitment rate: Unknown Region: Wageningen (The Netherlands)
Interventions	Number of experimental conditions: 2 Number of participants (analysed): Choice condition = 34 No‐choice condition = 36 Description of intervention: “Each child was exposed 12 times to six familiar target vegetables at home during dinner, which is the traditional hot meal including vegetables in The Netherlands….the choice group received two types of vegetables from which to choose, or they could choose to eat both vegetables during the meal.” Duration: 12 days Number of contacts: 12 Setting: Home Modality: Face‐to‐face Interventionist: Parents Integrity: No information provided Date of study: Unknown Description of control: “The no‐choice group received only one type of vegetable per dinner session”
Outcomes	Outcome relating to children's fruit and vegetable consumption: “The main outcome of the study was the children’s intake (in gram) of the vegetables. Vegetable intake was measured by weighing their plates before and after dinner (left overs).” Outcome relating to absolute costs/cost effectiveness of interventions: Not reported Outcome relating to reported adverse events: Not reported Length of follow‐up from baseline: 12 days Length of follow‐up post‐intervention: Immediately Subgroup analyses: None Loss to follow‐up: Overall = 6% (not specified by group) Analysis: Sample size calculation was performed
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomly allocated to experimental group but the random sequence generation procedure is not described
Allocation concealment (selection bias)	Unclear risk	There is no information provided about allocation concealment and therefore it is unclear if allocation was concealed
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Vegetable intake (objective measure): Children’s vegetable intake was measured by weighing their plates before and after dinner (left‐overs). There is a low risk of performance bias
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Vegetable intake (objective measure): Children’s vegetable intake was measured by weighing their plates before and after dinner (left‐overs). There is a low risk of detection bias
Incomplete outcome data (attrition bias) All outcomes	Low risk	70/75 (93%) children completed the study and therefore risk of attrition bias is low
Selective reporting (reporting bias)	Unclear risk	The primary outcomes reported in the paper align with those specified in the trial registration. However in the trial registration the food diary is listed as a secondary outcome but the results are not reported in the outcome paper
Other bias	High risk	Despite random assignment, children in the no‐choice group on average liked vegetables better than children in the choice group (P < 0.01) and therefore baseline imbalance between groups