The results of this pilot evaluation suggest that the MFVP may have helped to increase students' exposure to fruit and vegetables across all grade levels, which is consistent with the program's primary aim. The data suggest that the program modestly affected eighth- and 10th-grade students' attitudes, preferences for, and intentions to eat more fruit; it also appears to have helped to increase eighth- and 10th-grade students' consumption of fruit and fresh fruit during the school year. These results are similar to selected findings in other studies examining the effects of distributing free fresh fruit and/or vegetables.
For example, Jamelske and colleagues21
found that students at schools distributing fresh fruit and vegetable snacks were more willing to try new fruit and vegetables at school than were control-group students; these effects did not appear to transfer to home. Similarly, Fogarty and colleagues22
found that children's fruit consumption increased as a result of a national school fruit program in which children aged 4–6 years were given a daily piece of fruit at school. The effects dissipated after children aged out of the program. Further, Bere et al.23
found strong effects of a fruit and vegetable snack and educational program on students' fruit and vegetable consumption at school and overall (school and home combined). Effects were still observed one year after the distribution of free fruit and vegetable snacks had ended (parents could and did subscribe to the program at a minimal cost).
The Mississippi program did not appear to increase vegetable consumption, with one exception—on the student questionnaire, 10th-grade students reported that they were more likely to eat the vegetables offered at school breakfast and lunch. These results were consistent with observations of administrators, parents, and students, suggesting that vegetables were less popular than fruit. Other studies aimed at improving fruit and vegetable consumption have noted similar findings. For example, Acheampong and colleagues24
noted that the program entitled “5 a Day the Bash Street Way” increased consumption of fruit but not vegetables. In focus groups, students in Mississippi indicated a preference for cooked vs. raw vegetables, which may be a difficult challenge to overcome for these types of programs. Other strategies, such as offering low-fat dips, may be more feasible. School staff reported that serving vegetables with dip increased students' willingness to try them. Students reported similar views. The recall data suggested that students' consumption of all vegetables decreased at school; however, this finding was no longer significant when potatoes were excluded from vegetable servings, suggesting that, at a minimum, the program did not have a negative impact on eating vegetables promoted by the program.
The program appeared to be more successful with eighth- and 10th-grade students than with fifth-grade students. Elementary school students' willingness to try and preferences for new fruit and vegetables actually decreased. The lack of positive findings among fifth-grade students is consistent with research on food preferences across the life span.25,26
Younger children tend to prefer sweeter, more energy-dense foods (e.g., foods with high caloric content by weight, such as butter) over energy-dilute foods (e.g., foods with low calorie content by weight, such as vegetables and plain popcorn), a pattern that is thought to be influenced by physiological needs, and one that begins to change at puberty.25
Children are also predisposed to reject new foods—except those that are sweet or salty26
—and they have lower preferences for vegetables.27
Skinner and colleagues27
also found that the number of disliked foods increased as children tasted new foods; our findings were consistent with this research. Indeed, the fifth-grade students reported tasting more fruit and vegetables during the school year; at the same time, they reported liking fewer of the fruit and vegetables they tasted.
Despite the many factors contributing to children's food preferences, current research suggests that it is possible to influence food preferences through repeated tastings or exposures. For example, Wardle and colleagues found that children's liking and consumption of sweet red pepper increased significantly with repeated daily exposures during the course of eight days.28
Others have noted that between eight and 15 exposures are needed to alter preferences.29
During the MFVP, staff reported that they tended to stop purchasing vegetables that were rejected immediately by children to avoid waste and to maintain students' interest in the program. It may be important to consider a different strategy for introducing new vegetables through school-based fruit and vegetable snack programs to maximize success. For example, it may be helpful to host tasting events during repeated days (eight to 10 days) with new vegetables before buying them for school-wide distribution.
Other research emphasizes the importance of family influences and availability in fruit and vegetable consumption. For example, eating with family members, especially parents, is associated with increased consumption of fruit and vegetables.30,31
Similarly, availability, particularly at home, is linked to increased consumption.32
Finally, parental modeling is important to promote consumption.27,33
These factors could be beneficial leverage points for fresh fruit and vegetable programs. Future programs may consider capitalizing on this potential by emphasizing parents' role in increasing fruit and vegetable consumption through eating as a family, making fruit and vegetables available at home, and modeling consumption. Anecdotal evidence from the evaluation suggests that the free fresh fruit and vegetable program could help with these influences. During focus group interviews with parents, several parents of children at varying grade levels commented that their children asked them to buy fruit and vegetables that were served at school, which they did.
Interestingly, staff reactions alone would have suggested much stronger outcomes for fifth-grade students than were captured with the student questionnaire. More research is needed on how to best assess the effects of this type of program on younger children. Although there is empirical support for collecting self-administered nutrition-related questionnaires from fourth- and fifth-grade students,14
and there did not appear to be significant comprehension challenges during questionnaire pilot testing or administration, it is possible that the younger students may have had more challenges than the older students in understanding some of the questionnaire items. Nonetheless, the research on collecting data from children suggests that, in general, children aged 9 years and older are capable of contributing valid information about their own feelings, experiences, behaviors, and physical symptoms through many of the traditional data collection methods, such as diaries, in-person interviews, written surveys, and computer-based surveys.34
Limitations and strengths
The evaluation had several limitations. Data were collected within a one-group (no comparison group) pretest/posttest design, limiting the ability to attribute changes in students' attitudes, preferences, and eating behaviors to the program. Without a comparison group, the influences of factors such as seasonality, national attention on the issue of obesity, or other unknown trends cannot be ruled out.
If seasonality were an issue, biases resulting from seasonal availability of produce would have had the most significant effect on the types of fruit and vegetables eighth- and 10th-grade students reported eating on the food frequency scale and 24-hour recall interviews. It is possible that students in Mississippi may have had more fresh fruit and vegetable options available in fall than in spring (Personal communication, Dr. T. Carithers, University of Mississippi, August 2005); however, the program may have helped equalize the availability of fresh produce in spring somewhat by providing fresh fruit and vegetable snacks at school. Further, analyses compared data collected in early fall (pretest) and late spring (posttest) rather than from two stark opposite seasons (e.g., summer and winter); this may have helped to minimize the threat of seasonality. Finally, for both types of data, we examined the total number of servings of fruit and vegetables (fresh, frozen, dried, or canned), further minimizing the biases that might result from examining consumption of fresh produce alone.
Other important limitations include the sample size for the dietary recall interviews, intervention intensity, and the stage of intervention implementation. The sample for the dietary recall interviews was relatively small. We established the sample size to allow for overall group estimates, with an expectation of being able to detect small to medium effects in the mean number of servings of fruit or vegetables. The sample size was too small to support tests of subgroup differences (e.g., gender or grade-level differences), limiting the ability to assess program effects among subgroups.
The intervention (distributing free fruit and vegetables) was relatively modest. Schools augmented the distribution with a variety of nutrition education activities, but students' exposure to these activities was not assessed at the individual level, thereby limiting conclusions about how these may have affected the outcomes.
Finally, at the time of this evaluation, the MFVP was a new program for Mississippi schools, and the evaluation year represented the first year of implementation. Schools experienced a range of start-up and implementation challenges that could have affected the program's overall impact; nonetheless, schools suggested the challenges were limited, and program coordinators reported that they were able to address most of the challenges relatively early in the school year.
The study also had a number of strengths. For example, it had high participation and retention rates in both the student surveys and 24-hour recall interviews. It included both elementary and secondary-level students, and analyzed their survey data separately. Similarly, this study examined fruit- and vegetable-related data separately. Although some studies have taken a similar approach, many studies have combined fruit and vegetable indicators, potentially obscuring differential program impacts. This study more specifically addressed the program's goals by examining the recall data with and without potatoes and only fresh vs. all fruit and vegetables, providing a more specific analysis of how these programs might impact student outcomes. Finally, we examined consumption of fruit and vegetables as measured in the recall both in school and overall, providing an opportunity to better understand where behavioral influences may be occurring.