Repeated exposure in a natural setting: a preschool intervention to increase vegetable consumption

Laboratory and home-based research suggest that repeated exposure to vegetables may increase consumption among children. Effectiveness of repeated exposure to vegetables has not been tested in a community-based preschool setting.

This randomized controlled trial tested the hypotheses that children who are served unfamiliar vegetables repeatedly in the preschool lunch setting will increase consumption of them, and that consumption will be influenced by peer eating behaviors and parental feeding behaviors.

Data were collected in two private preschools in a small northeastern city in 2007. Ninety-six children (aged 3 to 6 years) participated.

Schools were randomly assigned to condition. During the first 6 weeks, Preschool A served three vegetables at lunch on 10 separate occasions (ie, 30 days of exposure), while Preschool B continued routine practice. In the 7th week, schools reversed conditions and Preschool B served the vegetables for the next 6 weeks. Consumption data were collected daily in the intervention school and at baseline and post-intervention meals in the control school. PRIMARY OUTCOMES/STATISTICAL ANALYSES: Analysis of variance was used to examine the effect of vegetable exposure on vegetable intake; multilevel models were used to examine the effect of peer eating behaviors and parental feeding practices on vegetable intake.

Repeated exposure did not increase vegetable consumption. Greater consumption by tablemates was a significant predictor of greater vegetable consumption; across the three vegetables, 1 g of peer intake was associated with roughly a 1/5-g intake increase among the subjects. Overall, children demonstrated wide fluctuation in vegetable consumption from day to day, creating as much variability within subjects as between them.

Further research should explore the conditions necessary for repeated exposure to increase vegetable consumption in preschool settings. Creating opportunities for young children to serve as peer models has promise as a strategy to promote vegetable consumption.