Abstract: The purpose of this study was to compare a social marketing campaign to a 5-a-Day curriculum-only intervention, and to no intervention on increasing fruit and vegetable consumption. Researchers developed the intervention based on formative research needs assessment with the target audience. Outcome measures included fruit and vegetable consumption, self-efficacy, asking behaviors, and attitudes toward presentation of fruit and vegetables. Thirteen significant changes from pretest to posttest were noted in the social marketing intervention, and nine significant changes in the curriculum-only intervention. Implications for practice include using multicomponent interventions and incorporating both a cognitive approach and school-based environmental changes.
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The current level of fruit and vegetable consumption in the United States is below recommended levels for both adults and children. Adult consumption levels are estimated between 3.5 and 5.2 servings per day (Johnston, Taylor, & Hampl, 2000; Thompson et al., 1999). Only 20% of children, aged 2-18, and 23.9% of adolescents, grades 9-12, eat five or more servings of fruits and vegetables per day (CDC, 2000; Krebs-Smith et al., 1995).
One promising approach to increasing fruit and vegetable consumption among adults, adolescents, and children is social marketing, defined as "the application of commercial marketing technologies to the analysis, planning, execution, and evaluation of programs designed to influence the voluntary behavior of target audiences in order to improve their personal welfare and that of their society" (Andreasen, 1995, p.7). Social marketing strategies have been used in varying degrees for nearly 30 years in international and domestic settings, their primary intent being to improve health conditions and quality of life in general (Neiger et al., 2001; Schellenberg et al., 2001), however, there is relatively little research documenting whether this consumer-focused, consumer-driven approach is effective among adolescent populations.
The primary objective of this study was to examine the effect of a social marketing campaign on fruit and vegetable consumption among middle-school adolescents compared to a 5-a-Day curriculum intervention and to no intervention. Further, the effect of the interventions on school faculty, and parents of students was examined. The paper outlines for practitioners how social marketing can be applied in a public health setting, and it may serve as a model for other practitioners in implementing social marketing activities.
DESIGN AND IMPLEMENTATION
Design. This study used a quasiexperimental design with repeated measures. The independent variable was type of intervention: social marketing (SM), 5-a-Day curriculum-only (CO), or no-intervention (NI).
The development of the SM intervention was based on results of formative research. Formative research is defined as identifying the wants and needs of the target audience, as well as factors that influence its behavior including benefits, barriers, and readiness to change (Bryant, 1998). Formative research included 100 one-on-one interviews with students and six focus groups with students, parents, faculty, and staff. All interventions resulting from formative research were pretested with the priority population, and revisions were made accordingly.
The research team used the qualitative software Nonnumerical Unstructured Data Indexing Searching and Theorizing (NUD*IST [4.0.sup.a]) to organize the formative research data to write a summary of the findings. These summary reports guided the development of the interventions. A self-scoring checklist was developed to ensure that the research team developed interventions in response to consumer preferences as identified in the formative research. The checklist included 14 statements regarding factors such as the degree to which the research team had read the data report, referred to data in their comments, and made comments in context of the needs and wants of the target audience.
The 8-week SM intervention consisted of school-wide events, communications, and food service modifications in the cafeteria. School-wide events included a kick-off assembly where students were introduced to 5-a-Day, serving sizes, and intervention components; a 4-week contest where students recorded the number of servings of fruit and vegetables they ate; weekly snack breaks during reading period; and an ending cafeteria celebration. Communications included 5-a-Day related fruit and vegetable posters in classrooms, a banner in the cafeteria, messages on an electronic scrolling marquee, announcements over the public address system, and a display in the front hall. Food service modifications included increasing the type and variety of fruits and vegetables served in the cafeteria (e.g., vegetable pizza, grapes, kiwi, etc.), changing how they were displayed (e.g., individual serving containers, serving dip with vegetables, and not offering over-ripe bananas, etc.), and providing disposable food trays that enabled students to carry multiple food items.
Parent-focused interventions occurred at the SM school only, and included communications and one event. Communications included four 5-a-Day newsletters that were mailed home, and a display at the parent-teacher conference. The display contained food samples, 5-a-Day information, recipes, and a 5-a-Day cookbook. Parents who did not attend the conference received the cookbook in the mail. The parent event was a series of four 1-hour cooking classes held at the school once a week for 4 weeks.
The faculty at the SM school participated in the contest to eat more fruit and vegetables. They were also exposed to all the 5-a-Day communications at the school.
At the CO school, students enrolled in seventh-grade health classes during two trimesters (A or B) received a series of four 5-a-Day lessons taught by the health teacher. The four-lesson limit was a directive from the school district. The content of the lessons included serving sizes, positive effects of eating five fruits and vegetables, goal setting, barriers, strategies to overcome barriers, strategies to include more fruit and vegetables in the diet, personal assessment of intake, and comparing intake to recommended levels. There were no interventions for the faculty or parents at this school.
Recruitment and Sampling. Three middle schools (7th-8th grade) within a large, metropolitan, inner-city school district were selected for participation. A convenience sample was used to allow researchers greater flexibility in selecting schools composed of ethnically diverse and low-income students and families (criteria required by the Centers for Disease Control and Prevention, which funded the study). Therefore, the participating schools were matched initially, by ethnic composition and socioeconomic status (i.e., percent of students eligible for free and reduced lunch), and assignment to treatment condition was made prior to pretesting.
A random sample, stratified by grade and gender, of students from both the SM school (N = 177) and NI school (N = 165) were selected to complete a pre-post survey; the CO school sample included all students who were enrolled in health classes during either trimester A or B, and were present on the day the pretest was administered. The sample size was selected based on a power calculation for a sign test (alpha .05, 2-tailed, .80 power) (SamplePower 1.0, 1997). The sample was nearly equal for gender and the mean age was 13.01 years. Retention rates ranged from 87% to 93%.
A convenience sample of parents from each school was selected to participate in a pre-post telephone survey (SM: N = 110; CO: N = 103; NI: N = 101). The schools would not provide a list of telephone numbers of parents; therefore the research firm who conducted the survey purchased a sample from a vendor (a standard procedure in survey research).
All faculty at each school were asked to complete a pre-post paper-and-pencil survey on a voluntary basis (SM: N = 22; CO: N = 16; NI: N = 21). The response rate was 50% to 57%. The school district prohibited the collection of demographic and socioeconomic data for any of the study participants, including faculty and parents.
