Modifying children's food preferences: the effects of exposure and reward on acceptance of an unfamiliar vegetable

J Wardle, M-L Herrera, L Cooke, E L Gibson

The aim of this study was to evaluate two interventions (one reward-based and one exposure-based) for increasing children's acceptance of an unfamiliar vegetable compared with a no-treatment control. It was predicted that the exposure condition would increase liking for, and consumption of, the vegetable relative to either the reward or control group. Using a randomized controlled design, participants were assigned to one of two intervention groups (exposure or reward) or to a no-treatment control condition, for a 2 week period. Liking for, and consumption of, red pepper was assessed before and after the treatment period. The study was conducted in three primary schools in London. Parental consent was obtained for 49 out of a possible 72 children. Interventions comprised eight daily sessions during which participants in the exposure group were offered a taste of sweet red pepper and told that they could eat as much as they liked. Participants in the reward group were shown a sheet of cartoon stickers and told that they could choose one of them on condition that they ate at least one piece of the pepper. The exposure-based intervention significantly increased both liking (P=0.006) and consumption (P=0.03) compared with the control group. The outcome of the reward intervention was intermediate and did not differ significantly from the exposure or control conditions. Repeated exposure to the taste of unfamiliar foods is a promising strategy for promoting liking of previously rejected foods in children.