de Wild 2015b

Methods	Study design: Randomised controlled trial – semi‐cross‐over Funding: "European Community’s Seventh Framework Programme (FP7/2007‐2013) under the Grant agreement No. 245012‐HabEat."
Participants	Description: Preschool‐aged children recruited from 2 daycare centres in Wageningen, the Netherland N (Randomised): 45 children Age: 18‐45 months (mean = 32.6 months) % Female: 49% 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: “recruited from two day‐care centres in Wageningen, the Netherlands. Parents signed an informed consent for their child’s participation.” Recruitment rate: Unknown Region: Wageningen (The Netherlands)
Interventions	Number of experimental conditions: 2 Number of participants (analysed): Parsnip crisps‐tomato ketchup/red beet crisps‐white sauce = 19 Red beets crisps‐tomato ketchup/parsnip crisps‐white sauce = 20 Description of intervention: “Half of the participants received red beet crisps combined with tomato ketchup (TK [C]) consistently paired with parsnip crisps combined with white sauce (WS [UC]). The other half of the participants received the reverse, i.e. red beet crisps + WS(UC) and parsnip crisps + TK(C).” Duration: 7 weeks Number of contacts: 14 exposures (twice/week) Setting: Preschool Modality: Face‐to‐face Interventionist: Daycare leaders Integrity: No information provided Date of study: Unknown Description of control: N/A
Outcomes	Outcome relating to children's fruit and vegetable consumption: As‐desired consumption of vegetable crisps (grams). “Consumption of crisps and dip sauces were measured by pre‐ and post‐weighing on a digital scale with a precision of 0.1 g.” 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: Post‐test 1: 9 weeks Post‐test 2: 4 months (2 months after conditioning) Post‐test 3: 8 months (6 months after conditioning) Length of follow‐up post‐intervention: Post‐test 1: immediate Post‐test 2: 2 months Post‐test 3: 6 months after conditioning Subgroup analyses: None Loss to follow‐up (at 2 and 6 months): Overall: 5%, 33% (not specified by group) Analysis: Unknown if 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 crisps intake (objective): The children were not aware that their intake was measured or which condition they participated in and so the risk of performance bias is low
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Vegetable crisps intake (objective): The outcome was vegetable chip and dip intake (each assessed separately) by weighing amount before and after consumption. It is not clear who (i.e. researchers or daycare centre staff) weighed the chips & dip, and whether or not they were blinded. Blinding of outcome assessors unlikely to influence outcome
Incomplete outcome data (attrition bias) All outcomes	High risk	Of the 45 children, 6 were excluded because they had no intake at all of the dip sauces. Of the remaining 39 children, 26 (67%) completed the 6‐month follow‐up. The risk of attrition bias is high
Selective reporting (reporting bias)	Unclear risk	The trial registration reports a secondary outcome that is not reported in the outcome paper
Other bias	Low risk	Contamination, baseline imbalance, & other bias that could threaten the internal validity are unlikely to be an issue