Rewards can be used effectively with repeated exposure to increase liking of vegetables in 4–6-year-old children

Abstract

Objective: 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. Design: A randomized controlled trial evaluated the effectiveness of exposure only (EO) and exposure plus reward (E1R), 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. Setting: The study took place in Adelaide, South Australia. Participants were selfselected in response to local media advertisements seeking to recruit parents finding it difficult to get their children to eat vegetables. Subjects: Participants were 185 children (110 boys, seventy-five girls) aged 4-6 years and their primary caregiver/parent (172 mothers, thirteen fathers). Results: The E1R group was able to achieve more days of taste exposure. Both EO and E1R 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 E1R and control but not for EO. Conclusions: 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.

Understanding and changing children’s sensory acceptance for vegetables

“…Our finding is in line with those studies and, similarly, an increase in acceptance after exposure to a multiple target vegetable was found. In contrast, we did not find an effect on vegetable intake with repeated exposure to a single vegetable, whereas others reported positive effects on intake (52,63,64) . Our measures of vegetable intake differed from those studies, as they had measured intake of the vegetable as part of the acceptance rating procedures, whereas we used separate measures of intake of vegetables relating to daily intake and intake in a meal.…”

“…The overall conclusion that emerges from this research is that repeated exposure is effective in increasing intake of vegetables in children, and that FFL and FNL offer no benefits beyond those found through the repeated exposure effect (52)(53)(54)(55)(56)(57)(58)(59)(60)(61)(62) . Our study added to this knowledge by comparing two variants of a repeated exposure paradigm for its effectiveness to increase vegetable acceptance and intake.…”

“…Approximately 10 exposures are needed to change liking, but this number depends on the novelty of the stimulus, initial liking when a stimulus is not novel, and individual characteristics (50) . Previous experience with foods also affects number of exposures needed, as the number of exposures needed by children decreases with increased variety in their diet (52) . Flavour-flavour learning (FFL) and flavour-nutrient learning (FNL) are both forms of associative learning or classical conditioning, whereby the valence (hedonic value) of a conditioned stimulus (CS) changes through simultaneous presence of an unconditioned stimulus (US) that either has a positive (liked) or negative (disliked) valence (53,54) .…”

“…Several exposure studies measured vegetable acceptance (52,63,64) and found an increased acceptance with repeated exposure to a single target vegetable. Our finding is in line with those studies and, similarly, an increase in acceptance after exposure to a multiple target vegetable was found.…”

“…This strategy is simple to adopt by parents and should be further promoted in public health messages and by health professionals that provide individual advice to parents on their children's eating habits. The use of a small non-food reward promotes willingness to try the vegetable (52,76) . Exposure to multiple target vegetables seems a promising strategy to increase vegetable intake more than what can be achieved using single target vegetable exposure, and further research is needed in this area.…”