Comparison of a 5-a-Day social marketing intervention and school-based curriculum

American Journal of Health Studies, Winter, 2002 by Rosemary Thackeray, Brad L. Neiger, Heather Leonard, Joan Ware, Gregory J. Stoddard

Availability of fruit and vegetables at home has been reported as a factor in fruit and vegetable consumption (Corwin, Sargent, Rheaume, & Saunders, 1999; Hearn et al., 1998). In the present study, parents reported serving fruit for dinner four to six times per week and serving vegetables for dinner and fruit, fruit juice, or vegetables as snacks every day. From pre- to posttest, the SM group parents reported significant differences in serving fruit at dinner, vegetables at dinner, and fruit, fruit juice, or vegetables as a snack. This is in contrast to the literature by Perry et al. (1998) that reported no change in parent behavior. The NI group also reported increase of frequency of serving fruit at dinner, and fruit and vegetables as a snack. One possible explanation for this could be that barriers were reduced as availability and variety of fruit and vegetables increased with the season. It has been reported that adults eat more fruit and vegetables in the summer, or when in season (Uetrecht, Greenberg, Dwyer, Sutherland & Tobin, 1999).

There was no increase in fruit and vegetable consumption for faculty in any of the three study groups. These results are both similar to and in contrast to the two 5-a-Day studies that reported the impact of a school-based intervention on faculty. Story et al. (2000) found that faculty who had taught a nutrition curriculum in their classroom reported that their consumption of fruit and vegetables was higher than usual. Resnicow et al. (1998) reported that a combination of a classroom curriculum and an employee wellness program had no impact on either student or teacher outcomes.

The use of convenience samples reduces the ability to generalize findings to all ethnically diverse and low-income populations, as well as middle-school students. However, non-probability samples are generally acceptable when the study of relationships among variables is more important, as in this study, than describing a population in general (Cozby, 1997). Both intervention groups completed a posttest one month after the conclusion of the intervention. The curriculum-only intervention was shorter, as a result of the four-lesson limit mandated by the school district. But this duration is supported by Contento et al. (1995) who reported a median value of three hours for school-based nutrition education. Because of the difference in lengths of intervention, the elapsed time between the pretest and posttest was shorter for the CO groups compared to the SM group and NI groups. Finally, all measures were self-report and subject to bias. Although this does not represent a phenomenon unseen in most field research that relies on voluntary participation, it does represent a limitation. This bias is reduced when valid and reliable scales are used as in this study.

CONCLUSION

While changes in overall fruit and vegetable consumption among students was limited to choosing more fruit at lunch, 13 significant changes were noted in the SM intervention and 9 significant changes were detected in the CO intervention among students, parents, and teachers. In general, a multicomponent intervention that is based on social marketing principles, and that combines cognitive approaches with environmental changes may potentially be most effective in changing fruit and vegetable consumption among adolescents, though not tested in this intervention. Even a well-designed social marketing intervention that focuses almost exclusively on environmental changes to support healthy behaviors may not accomplish the same degree of change without this cognitive element (i.e., specifically addressing servings and serving sizes, how to consume adequate servings, and how to reduce barriers).