« Kids choice » school lunch program increases children’s fruit and vegetable acceptance.

The "Kids Choice" school lunch program used token reinforcement, food choice, and peer participation to increase children's fruit and vegetable consumption without later drops in food preference sometimes found in past research and often called 'overjustification effects.' Participants included 188 school children (92 boys, 96 girls; mean age = 8.0; 95% Caucasian). After four baseline meals, children were randomly assigned for 12 meals to receive token reinforcement for eating either fruits or vegetables. Observers recorded fruit and vegetable consumption and provided token reinforcement by punching holes into nametags each day children ate their assigned foods, then once a week children could trade these tokens for small prizes. Fruit and vegetable preference ratings were gathered with child interviews during baseline, and during follow-up conditions two weeks and seven months after the token reinforcement program. Consumption increased for fruit and for vegetables and the increases lasted throughout reinforcement conditions. Two weeks after the program, preference ratings showed increases for fruit and for vegetables. Seven months later, fruit and vegetable preferences had returned to baseline levels, suggesting the need for an ongoing school lunch program to keep preferences high, but also showing no signs of "overjustification effects" from the token reinforcement used in the "Kids Choice" school lunch program.