Community-based interventions for enhancing access to or consumption of fruit and vegetables among five to 18-year olds: a scoping review

Low fruit and vegetable (FV) consumption is one of the top 10 global risk factors for mortality according to the World Health Organization (WHO) [1]. Increased FV consumption can help protect overall health status and reduce both disease risk and burden [2]. Fruit and vegetable intake among children is of particular interest due to growing recognition of the importance of nutrition for growth, development, and prevention of chronic diseases such as cardiovascular disease and obesity [2]. A number of studies have shown that childhood FV consumption patterns and preferences are predictive of patterns in adolescence and adulthood [3‐6]. It has been estimated that 2.7 million lives could be saved each year through increased and adequate FV consumption. In addition, this increased consumption of FV would decrease the worldwide non-communicable disease burden by almost 2% [7].

Consumption of FV is limited by a lack of access to FV, which is a conspicuous issue facing low- and middle-income countries, but also affects high-income countries [8]. While FV intake is directly associated with socioeconomic status, many individuals do not meet recommended guidelines for FV intake regardless of country of origin and income status [8]. A systematic review of potential determinants of FV intake and intervention strategies found that availability and accessibility of FV and preferences had the most consistent positive relationship with FV consumption [9]. Another more recent systematic review of determinants of fruit and vegetable consumption among children and adolescents identified many individual level determinants including direct gradients associated with intake and socioeconomic status, home availability and accessibility, and parental intake patterns [8]. The environmental factors that influence consumption of FV extend beyond the individual to include: physical, economic and social factors; supply, availability and accessibility (includes costing); availability of FV in stores in the local community, schools, community-based programs; and policies at global, regional, national and local levels [8‐11]. Nutrition knowledge, preferences, and self-efficacy are also associated with increased intake of FV [8, 12, 13] and therefore have been included as secondary outcomes of interest for this review. Enhanced understanding of relevant intervention research and its impact on both access to and consumption of FV, as well as chronic disease health indicators, can provide guidance to public health decision-makers and policy-makers in the establishment and maintenance of effective and supportive nutritional programs.

Three reviews have previously examined the effect of community interventions to increase FV consumption, however, one review has not been updated in over 10 years [14] and the two others were limited to school-based interventions in high-income countries [15, 16]; in these the previous reviews, the important issue of access to FV was not addressed [14‐16]. The purpose of this scoping review is to identify and map literature that has evaluated the effects of community-based interventions designed to increase FV access and/or consumption among five to 18-year olds. The effectiveness of upstream interventions targeting children and adolescents (18 years and under) is of particular interest to decision makers since FV consumption patterns established in childhood tend to persist through adulthood [3‐6]. We are aware of a potentially complementary review that intends to examine interventions to increase FV consumption in preschool children (under 5 years) [17] and therefore focused on 5 to 18 year olds. Due to the large scope of this review topic, interventions focused solely on adults or specialized populations such as those with a specific chronic disease were considered beyond the scope of this review.

The initial step in this scoping review involved defining the research question in a PICOS (Population-Intervention-Comparison-Outcome-Study Design) format. The PICOS question was defined by the research team and refined in collaboration with two public health librarians who subsequently implemented the search.

The Cochrane Public Health Group acknowledges that a scoping review is a critical step in defining a systematic review question [347]. We identified a large volume of interventional research found within peer-reviewed and grey literature associated with FV access and consumption. Using a scoping review process [347], we categorized these studies with respect to outcomes based on a number of parameters such as study design, target audience, intervention location, intervention strategy, and intervention deliverer.

The predominant outcome measure was consumption. In comparison, harm was included as an outcome measure in an extremely small number of studies, which may indicate that there are few risks or potential harms associated with interventions used to increase FV consumption. It also possible that harms were overlooked given that few of these studies evaluated interventions implemented in low- or middle-income countries where populations could be more vulnerable. The bias of studies toward high-income countries and not low- and middle-income countries warrants further investigation as intervention effectiveness may vary across these populations.

While consumption measures were commonly reported, this review identified a small yet important subset of literature examining the effectiveness of interventions that increase access to FV. We believe this to be a relatively overlooked but critically important issue since consumption of FV is contingent upon access to them. A number of articles discussed FV accessibility; however, many of these studies lacked before-after comparison data or other comparison groups. These studies were excluded during full text relevance screening since they did not evaluate the impact of an intervention or policy. Specific measures of access were lacking in included studies; authors often identified a goal of evaluating the impact of interventions or policies to increase FV access but measured changes in consumption behaviors as a proxy for access.

Measuring FV access seems to be further complicated by a lack of consistent, meaningful, validated instruments; across the studies there was great variability in the ways access was measured. While some studies evaluated the impact of policy change on FV access and consumption, very few looked at population level initiatives or reported on population subgroups to be able to evaluate their impact on children aged five to 18 years. Further, despite the potential benefits of increasing access to FV, only a small number of studies partnered with farms or involved establishing community gardens. We also did not find any studies that evaluated changes in food supply or market inventory, two additional factors that influence access to and consequently consumption of FV.

This review has several methodological and operational limitations. A number of studies that examined knowledge, attitudes, awareness, and general health measures were excluded if they did not also examine either of our primary outcomes of access or consumption. It is possible, that relevant studies that explored our secondary outcomes were missed as a result of these methodological considerations. Operationally, the included studies were limited by the language fluency of the reviewers. Five articles published in Spanish were reviewed and included through titles and abstracts and full text phases, however because the Spanish-speaking reviewers were not available at the data extraction stage we excluded these papers. Data extraction was limited to studies published in English or French. Finally, including participants older than 18 years would have broadened the scope of available literature but the number of studies would not have been manageable for this scoping review. Therefore, the findings of this review are limited to children aged five to 18 years.

This scoping review sought to identify and map literature that has evaluated the effects of community-based interventions designed to increase FV access and/or consumption among five to 18-year olds. A variety of interventions have been used to support and increase FV consumption. Schools were the most common location for interventions, which were typically multi-faceted, targeted at individuals less than 15 years of age, and delivered by teachers or other school personnel. Additional research on implementing interventions in low- and middle-income countries is warranted based on the limited literature focusing on those populations. Finally, a somewhat narrow field of literature was identified with respect to FV access, suggesting that future research examining interventions to increase FV consumption should include direct outcome measures of FV access. Previously published syntheses revealed a gap in our understanding of the effectiveness of interventions that increase access to FV, since no syntheses that examined access to fruit and vegetables among children were found through our comprehensive literature search. While this scoping review identified several knowledge synthesis products, all were focused on FV consumption. Since consumption is contingent upon access, a focused systematic review that examines these interventions is needed. Such a review should examine and synthesize literature that seeks to increase access through interventions including (but not limited to): influencing FV supply, changing food environments, and enhancing FV sales in cafeterias and grocery stores.