The PRO GREENS intervention in Finnish schoolchildren – the degree of implementation affects both mediators and the intake of fruits and vegetables

Abstract

Little is known about the mediating effects of the determinants of fruit and vegetable (FV) intake in school-based interventions that promote FV intake, and few studies have examined the impact of the degree of implementation on the effects of an intervention. The present study examined whether the degree of implementation of an intervention had an effect on children's fruit or vegetable intake and determined possible mediators of this effect. The study is part of the European PRO GREENS intervention study which aimed to develop effective strategies to promote consumption of fruit and vegetables in schoolchildren across Europe. Data from 727 Finnish children aged 11 years were used. The baseline study was conducted in spring 2009 and the follow-up study 12 months later. The intervention was conducted during the school year 2009 -2010. The effects were examined using multilevel mediation analyses. A high degree of implementation of the intervention had an effect on children's fruit intake. Knowledge of recommendations for FV intake and liking mediated the association between a high degree of implementation of the intervention and an increase in the frequency of fruit intake. Knowledge of recommendations for FV intake and bringing fruits to school as a snack mediated the association between a low degree of implementation of the intervention and an increase in the frequency of fruit intake. Overall, the model accounted for 34 % of the variance in the change in fruit intake frequency. Knowledge of recommendations acted as a mediator between the degree of implementation of the intervention and the change in vegetable intake frequency. In conclusion, the degree of implementation had an effect on fruit intake, and thus in future intervention studies the actual degree of implementation of interventions should be assessed when considering the effects of interventions.Key words: School-based interventions: Fruits and vegetables: Implementation: Mediation Increasing children's fruit and vegetable (FV) intake is of great importance in addressing the childhood obesity epidemic and preventing chronic diseases in adulthood (1,2) . School-based interventions to increase children's FV intake have so far had positive effects of varying magnitudes (3 -6) . To plan and carry out successful school-based interventions, it is vital to know what kind of interventions are effective and why.Multicomponent interventions are more effective than single-component interventions in which free fruits or vegetables are distributed to children (4,6) . Multicomponent interventions that try to influence FV intake should attempt to influence factors that are associated with this behaviour. Such factors are, for example, knowledge of recommendations for FV intake, availability and accessibility, taste preferences, a liking for FV, parental modelling, attitudes towards FV and self-efficacy (7 -10) . In a review of the mediating factors of interventions to improve children's food intake, only attitude and, to a smaller degree, the knowledge...

Validation of 2 Brief Fruit and Vegetable Assessment Instruments Among Third-Grade Students

“…Evaluating the effectiveness of these programs within the constraints of community settings using validated dietary assessment tools remains a challenge. Current assessment tools used with children include food records or diaries 2,3 such as A Day in the Life Questionnaire (DILQ), 4 24-hour dietary recalls, 5 food frequency questionnaires, 6,7 and observational methods. 8 Evidence documenting the validity of these tools is typically based on 24-dietary recalls or weighed food records as reference standards, but many potentially useful tools remain unvalidated.…”

Curricular activities and change in determinants of fruit and vegetable intake among adolescents: Results from the Boost intervention

“…The intervention dose of an entire multi-component intervention (FV snacks, FV events and parental letters) was associated with 10–11-year-olds' knowledge of recommendations for FV intake and taste preferences for fruit (Lehto et al, 2014). …”

“…Previous interventions have not succeeded in changing vegetable intake among children and adolescents (Evans et al, 2012, Van Cauwenberghe et al, 2010, Lehto et al, 2014). This study indicates that curricular activities may be one successful strategy for changing determinants of adolescents' vegetable intake.…”

“…Curricular components in previous multi-component dietary interventions among children and adolescents (Wind et al, 2008, Bere et al, 2006, Lehto et al, 2014, Story et al, 2000, Anderson et al, 2005, Bessems et al, 2013) have targeted determinants such as taste preferences, dietary knowledge, awareness of national recommendations for FV intake, and practical skills. Two of these studies (Bere et al, 2006, Lehto et al, 2014, Story et al, 2000, Anderson et al, 2005) examined the impact of the entire intervention on changes in determinants of FV intake.…”

“…Two of these studies (Bere et al, 2006, Lehto et al, 2014, Story et al, 2000, Anderson et al, 2005) examined the impact of the entire intervention on changes in determinants of FV intake. Anderson et al (2005) found a greater increase in children's (6–7 and 10–11 years old) knowledge and subjective norms (perceived social pressure from school nurse) in the intervention group compared to the control group, while taste preferences were unchanged.…”