Purpose. To examine the application of the transtheoretical model (TTM) to fruit and vegetable consumption among economically disadvantaged African-American adolescents. Methods. Scales for measuring decisional balance, situational self-efficacy, and processes of change for fruit and vegetable consumption were developed and pretested with 57 economically disadvantaged African-American adolescents. The scales and measures for assessing stages of change, demographic variables, and fruit and vegetable consumption were administered to a separate sample of 262 participants. t-tests for independent samples and analysis of variance were used to examine differences in TTM variables and fruit and vegetable consumption across stages of change. Results. Two-factor solutions for decisional balance and processes of change and a three-factor solution for situational self-efficacy provided the best fit to the data. Alpha coefficients of reliability for the scales ranged from .77 (experiential change processes) to .91 (pros). Participants in action-maintenance stages evidenced higher pros, self-efficacy, and fruit and vegetable consumption and significantly lower cons than did participants in precontemplation and contemplation-preparation stages. Also, participants in action-maintenance stages used processes of change more frequently than did those in precontemplation-contemplation-preparation stages. The use of experiential and behavioral processes within these stages did not differ significantly, as posited. Discussion. Observed differences in TTM variables and fruit and vegetable consumption by stage of change in this sample of economically disadvantaged African-American adolescents were consistent with theory and previous applications of the model to fruit and vegetable consumption in adults. With replication studies, the TTM may be appropriate for designing interventions to increase fruit and vegetable consumption among this population.
Differential effects of planning and self-efficacy on fruit and vegetable consumption
