To examine whether parents offering a sticker reward to their child to taste a vegetable the child does not currently consume is associated with improvements in children's liking and consumption of the vegetable.

A randomized controlled trial evaluated the effectiveness of exposure only (EO) and exposure plus reward (E + R), relative to a control group, on children's liking and consumption of a target vegetable. Assessments were conducted at baseline and 2 weeks from baseline (post-intervention). Follow-up assessments were conducted at 4 weeks and 3 months from baseline.

The study took place in Adelaide, South Australia. Participants were self-selected in response to local media advertisements seeking to recruit parents finding it difficult to get their children to eat vegetables.

Participants were 185 children (110 boys, seventy-five girls) aged 4–6 years and their primary caregiver/parent (172 mothers, thirteen fathers).

The E + R group was able to achieve more days of taste exposure. Both EO and E + R increased liking at post-intervention compared with control and no further change occurred over the follow-up period. All groups increased their intake of the target vegetable at post-intervention. Target vegetable consumption continued to increase significantly over the follow-up period for E + R and control but not for EO.

The findings provide support for the effectiveness of using a sticker reward with a repeated exposure strategy. In particular, such rewards can facilitate the actual tastings necessary to change liking.