Farm-to-School programmes,benefits,health outcomes and barriers: A structured literature review

Introduction

In the USA, Farm-to-School programmes (FTSPs) offer a valuable approach to mitigating the childhood obesity epidemic and helping address food justice issues in rural and urban communities. The prevalence of obesity and type 2 diabetes has been steadily rising over the last two decades among children. A recent report by the US Centers for Disease Control and Prevention (CDC) shows that during 2017–2018, about 42.4% of the US population was obese, and 20% of children ages 12–19 had obesity (Behavioral Risk Factor Surveillance System, CDC). The situation is alarming when we examine obesity prevalence in young children. Obesity prevalence was 13.4% among 2- to 5-year-olds and 20.3% among 6- to 11-year-olds.

Childhood obesity can cause a myriad of metabolic health pathology in later life. Physicians, physician assistants and nurse practitioners are critical in delivering health care to the individual. They need to advocate for the public’s health since a physician or lower-level provider can often only see one patient at a time (Institute of Medicine, 2004). Physicians and health care professionals can advocate for better public health standards by informing patients about public health programmes, vaccinations, and extracurricular activities and non-governmental organisations that support them (Berkowitz and Borchard, 2009). One way to reduce childhood obesity is to eat and drink more healthily (Gerberding and Marks, 2004; Institute of Medicine, 2004). Numerous studies link changes in dietary behaviours to a reduction in childhood obesity (see Hoelscher et al., 2010; Story et al., 2009; Wright et al., 2012). In the USA, low-income communities and children within these communities are more likely to experience nutritional and health-related problems. Indeed, low-income communities across the USA are particularly vulnerable to increases in the prevalence of overweight in children (Sharma, 2006).

Healthy eating habits include fresh whole foods like fruit and vegetables (FVs), whole-wheat pasta and bread, low-fat dairy products, lean protein from beans, tofu, nuts and fish, and very little sugar (Wright et al., 2012). FTSPs can serve as a form of primary prevention tools against disease, building community resilience and addressing socioeconomic disparities in rural and urban areas (CDC, 1997; Sharma, 2006). Physicians, school administrators, school boards, private businesses, local producers and other health care professionals play a critical role in influencing the health of individuals and the public at large. Physicians will benefit from understanding the potential of FTSPs in reducing childhood obesity, promoting physical health and educating patients about the opportunities that FTSPs provide for the well-being of children and communities.

The causes of childhood obesity are multifaceted. Main concerns can be summed up in terms of food safety liability issues, the challenging ability of local producers to meet the school’s volume needs, and federal and state procurement laws regarding school food. Some localities are willing to pay more for local food, with food service staff procuring local foods through current distributors (e.g. study of Izumi, 2008, in Michigan). However, a significant proportion of children in the USA receive their nutrition from school lunch programmes funded by the federal government, and only recently have those programmes fully implemented higher nutritional standards.

It is essential to understand the motivations of food service leaders, producers and distributors operating in FTSPs. Farmers observe FTSPs increasing their profits along with educational and community benefits. Other producers may recognise the health and environmental benefits of FTSPs and see child education and community economic security as a key issue to be addressed (Bateman et al., 2014; Sharma, 2006). Distributors consider FTSPs as business opportunities to diversify their holdings. FTSPs have an impact on supporting awareness of FV consumption and healthy foods. In a review of 14 FTSP-related papers, Aloia et al. (2016) found that eight studies showed the positive effects of FTSPs in increasing FV consumption. The same authors also found that FTSPs that had a classroom component, increased high FV consumption. However, studies also suggest that an increase in FV consumption requires a combination of efforts and interventions – no single intervention can boost the consumption of FVs. On the contrary, small farms that are an integral part of communities, especially in rural areas, are disappearing, giving rise to larger corporate farms in the name of food security and safety regulation, thus affecting the diets of local residents. Health care professionals are keenly aware of the effects of diet on mental and physical health, and FTSPs can be a conduit for promoting well-being benefits for both farmers’ and children’s health.

Against this background, this study aimed to explore the following aspects of FTSP programmes – (a) health and related benefits, (b) benefits to stakeholders, (c) institutional barriers to FTSP uptake and implementation and (d) policy and environmental aspects of FTSPs.

Methodology

To address these issues, we conducted a systematic literature review of FTSPs and health benefits using Rowley and Slack’s (2004) review methods (SLR). SLR methodology advocates the use of a five-step methodology when conducting a literature review (Figure 1).

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Figure 1.

Steps involved in SLR methodology.

What constitutes a ‘FTSP’ and a ‘health outcome’?

Finding a ‘one-fits-all’ definition of FTSP is challenging. A wide variety of school-based initiatives can reasonably be called farm-to-school approaches. However, schools may have engaged in farm-to-school-related activities without naming them farm-to-school. Procuring fruit from local growers to serve in the cafeteria, integrating a school garden into the school’s health and science curriculum, organising field trips to local farms, and making it a school policy to buy from local producers where possible could plausibly be said to be FTSPs but may not be named as such.

It is also challenging to define the impacts of health outcomes related to FTSPs. Tangible and intangible, qualitative and quantitative, and direct and indirect benefits come under a comprehensive definition of the health outcomes related to the role of FTSPs in obesity reduction and healthy diet promotion. Any literature review of research on FTSPs and their health benefits may find it difficult to be inclusive of these very wide-ranging impacts and roles. This study is not entirely free from these limitations. Nonetheless, informed by representative literature on the topic, this review attempts to offer a reasonably systematic overview of key issues and concerns.

Benefits of FTSPs: awareness, healthy consumption, health impacts and beyond

Just under 20 years ago, Vallianatos et al. (2004) noted that FTSPs in California had resulted in a decrease in school vending-machine sales – specifically from vending machines containing calorie-dense but low–nutritional value foods and drinks. With an overall increase in school lunch programmes, salad bar participation rates have increased. In 2010, the Idaho Department of Education released a report on the effects of FTSPs on FV consumption across the state. The authors found that schools participating in FTSPs saw a 25% to 84% increase in FV consumption. There was also a 9% increase in school lunch participation. Just et al. (2012) studied 22 schools and photographed 48,000 lunch trays of schoolchildren in schools with an established FTSP to analyse the number of unique FV options available and schoolchildren’s eating. The authors found that 70% of vegetable servings were thrown away. Strawberries, Kiwi fruit and oranges were consumed the most but were the least available (except for oranges). Adding one additional FV menu item on a particular day increased the proportion of children who ate at least one serving of FV by 11.7%. As a specific type of food became more popular, children ate more of it. The study found that the total FV on the children’s plates increased, but the children wasted the same amount of food.

Schools’ food literacy programmes play a crucial role in shaping diets and choosing foods. Evans et al. (2012) evaluated FV consumption and food literacy programming in schools with an established FTSP. The methodology used was an unequal treatment-control post-test analysis in five schools. The schools implemented a healthy eating education programme using multiple programming modalities such as in-class learning, farm visits and so on. About 214 sixth- and seventh-grade students comprised the study population from five schools. The authors noted that students exposed to two or more intervention components scored significantly higher on FV intake, self-efficacy and knowledge, and showed significantly lower preferences for unhealthy foods than those exposed to less than two intervention components. In 2013, Moss et al. (2013) studied 65 third-grade schoolchildren at a rural Illinois elementary school to analyse the effects of FTSP educational programmes such as farm visits and cooking sessions on nutrition literacy and FV intake. Educational programmes and field trips significantly raised student knowledge of fibre, vitamins and minerals. Reported vegetable consumption was also increased.

Following a study by Moss et al.’s (2013), Yoder et al. (2014a) analysed food consumption and attitudes towards food among students from nine elementary schools, eight in urban areas and one in a rural district in Wisconsin, all with recently established FTSPs. The study adopted a quasi-experimental design that assessed willingness to try new foods and food nutrition literacy. Results showed that an FTSP significantly increased student willingness to try FVs, led to higher knowledge of nutrition and agriculture, and increased FV availability. FV consumption increased in students who scored lowest on baseline consumption surveys. Nested in the same population the study aimed to assess plate nutrient intake by photographing plates. The proportion of food items eaten was estimated and converted to caloric value. Results indicated that non-FV energy consumption decreased as the consumption of FV proportion increased. The longer the programme was run, the lower the non-FV consumption, a reduction estimated at 200 kCal per student.

In another study, Yoder et al. (2014b) investigated FV consumption and whether consumption of FV reduced calorie intake from non-FV energy among third to fifth-grade students in nine Wisconsin elementary schools, one of which was urban and the rest were classified as rural. The study on FV consumption was quasi-experimental in design using baseline food frequency questionnaires (FFQ) and follow-up after nutritional programming, along with photographs of lunch trays. This study found a significantly higher ‘willingness to try new FVs’ and ‘knowledge of nutrition/agriculture’ and lunch FV availability both with increasing prior FTSP exposure, and with each additional year, the FTSP was active in a school. While there was no effect on overall dietary patterns, FV consumption increased among those with the lowest intakes. In photo analysis, the percentage of trays with no FV consumption for continuing programmes decreased by 3%. A second study by the same author, using the same sample population, used photographs of 2,292 lunch trays to see if there was an association between FTSPs and an increase in FV calories consumed. The authors found that 41% of students in the study were obese, and 72% of the school lunches photographed were from schools allowing students to select their FVs. Data showed that a higher intake of FV energy displaced non-FV energy, but total calories did not decrease across FV energy intake groups. Trays with a significant number of FV calories were associated with a lower caloric intake of non-FV compared to energy intake from trays classified as ‘low’ density of FV calories. Trays from schools with a longer duration of FTSP decreased total and non-FV energy intakes from school lunches.

Yoder et al. (2015) analysed food waste on the cafeteria trays of Wisconsin third to fifth graders in schools with an established FTSP. The study population consisted of 7,117 trays from 1,877 students. After adjustment for sex and grade, there was no significant difference in the percent of the FV portion thrown away. Fresh fruit was wasted in a higher proportion to cooked fruit dishes. Cooked vegetable portions were wasted at a higher ratio than fresh vegetables. Salad bar FV was wasted more than cooked FV. The average food wasted was one tablespoon or two bites for an elementary school child. Davis et al. (2015) published a systematic review of studies on nutritional programming in schools with a school garden programme. The authors identified 13 studies that analysed the impact of school gardens and lessons incorporating local food and nutrition programming. Their review identified six studies that showed increased FV intake and four which showed no effect. Seven out of eight studies measuring food preference showed an increased appreciation for vegetables, improved attitudes about food identification and willingness to try new FVs. Hands-on nutritional curriculum integration such as farm visit field trips or farmer visits to schools, community support and instructor support were common themes in studies that had the most positive impacts.

Using a quasi-experimental study design and looking at 13 FTSP schools in three regions in South Carolina, Jones et al. (2015) investigated whether FTSPs affected mean FV consumption and the average percentage of students trying new FVs. Most students at these schools received free or reduced-price lunches (61% of all students in the study population). Children attending FTSP schools were significantly more likely to consume FVs and try new foods than control group schools. Parents reported that their children also started to eat more FVs at home. In addition, parents and caregivers acknowledged that FTSPs helped their local community.

FTSPs may also be criticised when it comes to food waste. Kropp et al. (2018) used an experimental study design to analyse the food waste rate in school cafeterias participating in FTSPs. The authors used three schools as the experimental group and three control schools, with a total sample size of 11,626 plates observed. Students at treatment schools ate 37% more servings of vegetables and 11% more fruit portions than the control schools, a statistically significant result. After controlling for school socioeconomic and demographic characteristics, treatment schools consumed 65% more vegetable portions, but fruit portions were not significantly increased. The authors found evidence of spillover effects of FTSP messaging, nudging and marketing, causing an increase in non-FTSP associated with FV consumption. In their discussion, the authors disclosed that there were more total vegetable products in the intervention than fruit, which could have driven the study findings.

Researchers have recently used experimental methods (pre- and post-intervention) to investigate the FTSPs. For instance, Landry et al. (2017) used a quasi-experimental study design to study FV consumption and nutrition attitudes in 124 fifth graders. The experiment lasted 1 month, and the sample largely consisted of White middle-class students. The post-intervention data revealed a significant increase in students’ belief scores (If I eat better, I will do better) than pre-intervention. The authors found no major consumption differences between pre- and post-intervention. Greer et al. (2018) used focus groups and a social-cognitive theory approach to assess students’ perceptions of locally grown food in diverse, low-income schools. Respondents reported that perceived outcomes associated with consuming local produce included ‘benefits the environment’, ‘builds community and trust’, and ‘keeps taxes down’. Overall, students perceived local produce to be of higher quality (e.g. ‘tastes better’, ‘fresher’) than nonlocal produce.

Finally, state laws and regulations can have a direct impact on FTSPs. For example, Sanjeevi et al. (2020) conducted a national observational study to assess the eating behaviours and weight status of 2,751 students in grades 10–12 in states with existing regulations about FTSPs. The authors found that adolescents in states with FTSP laws had greater intakes of whole fruit and snacks and lower intakes of soft drinks (sugar-based drinks or soda) than in those states with no regulations. Strong farm-to-school laws were associated with lower soft drink intakes in 2010. Among those in 12th grade in 2012, the study found lower soft drink intakes and lower overweight/obesity odds among adolescents in the states with effective and robust food laws. Strong FTSP laws were inversely associated with 2012 overweight/obesity odds, but only in states with strong competitive food laws.

FTSPs and state- and national-level policy environment

In the early 1990s, schools across the USA saw the implementation of several FTSPs. The activities included local food use in school meals and the integration of school gardens into school cafeterias and curricula. Consequently, the available literature tends to focus on the increase in farm-to-school-related programmes after the 1990s. The US Census started assessing or recording relevant activities from 2011 to 2012. The 2015 Census of Agriculture, for example, shows that around 63% of school districts with FTSPs completed at least three FTSP-related activities in 2015 (United State Department of Agriculture [USDA], 2017). The report also documented a significant increase in local food purchases (105%) by schools in the 2013–2014 school year. Over the same period, the number of cultivable school gardens increased nationwide to 7,100. As a result, school districts’ access to fresh FVs increased by 196% compared to 2011–2012. This trend continued to grow in the years following. At a national level, there has been an increasing growth of these and related activities in schools and preschools. State and federal policies from offices such as the Office of Community Food Systems and Food and Nutrition Service of the USDA have supported FTSPs and the closer linkage of schools to local food systems.

In a report based on the 2019 Farm-to-School Census, Bobronnikov et al. (2021) found that about two-thirds of all public and private school authorities reported participating in one or more farm-to-school activities. Nearly half (46%) indicated participating in seven or more different farm-to-school activities. Local food purchases accounted for 21% of the public and private school authorities’ total food budget. Bobronnikov et al. (2021) identify three critical findings of FTSPs. First, schools and school districts have significantly increased their spending on local foods. However, the definition of ‘local’ varies throughout the literature. Second, the authors note positive changes in school children’s willingness to try and accept FVs. Increasingly, people are aware that consuming FVs has a health- and weight-related educational impact. Third, the amount of income farmers receive from FTSPs has also increased, albeit the percentage of income for farmers from direct sales to schools is low. Farmers too consider FTS to have a broader sustained connection to the community. The review indicates that numerous policies are now supportive of the fact that FTSPs require State agencies to establish FTS activities or provide support for them through budgets. Finally, the study acknowledges the limited literature on FTSPs, particularly assessing programmes, economic impact, effects on healthy food consumption, and their effect on the agricultural sector and regional economies.

Barriers to the implementation of FTSPs

Discussion

There are many ways in which FTSPs can impact food consumption in schoolchildren. Major findings from this review include a critical result suggesting that the longer children are exposed to FTSPs, the more likely they are to increase their consumption of FVs. Increased intake of FVs subsequently displaces other calories that schoolchildren consume. However, given the nutritional tastes of children, fruit consumption can overtake and even replace vegetable consumption. This issue can be tackled in various ways using information from Yoder et al.’s (2015) work. This study found that children wasted a higher proportion of fresh fruit than cooked and vice versa for vegetable dishes. In consequence, individual school districts can use different preparation methods like more fresh, unprocessed vegetable dishes and more cooked fruit dishes. This study and others also noted that the longer FTSP is in a school, the less the wasted food. These studies lend credence to the idea that nutrition education plays a vital role in developing future eating habits, but cooking methods play an equally important role. Another finding from recent research, noted by Evans et al. (2012) and Davis et al. (2015), is that classroom nutrition education and the multi-level integration of nutrition education in schools has a synergistic effect on the availability of fresh FVs. Education outside of the school cafeteria helped drive demand for FVs when children were not in school and helped change health behaviours such as attitudes towards ‘junk’ foods.

FTSPs positively affect low-income students’ attitudes towards healthy and local foods (Greer et al., 2018). In this study, students had favourable views about local produce. They suggested that posters with local produce benefits displayed in the cafeteria would help raise awareness by reinforcing the benefits. It is well known that lower-income students suffer disproportionately high obesity, academic distress and food insecurity. This highlights the importance of diversity in the set up and provision of FTSPs and the importance of nutrition education. Since many low-income students cannot afford the variety of produce they receive from participating in FTSP, intervening early in disadvantaged populations may help reduce the cumulative effect of poor nutrition, poor access and potentially poor academic performance on the person’s future human potential. Extension and/or country workers can be crucial players in disseminating nutritional education and educating school administrators in implementing various interventions (Scherr et al., 2013). School nurses may also be critical for nutrition education since they are present in many schools (Muckian et al., 2017).

Conclusions and implications

In the USA, school-aged children face significant health and nutrition issues, including poor nutrition, childhood obesity and minimal nutrition information. A daily diet rich in FVs can help reduce the risk of many leading causes of illness and death, including heart disease, type 2 diabetes, some cancers and obesity. To combat childhood obesity, the USDA has advanced support for FTSPs. FTSPs aims to bring locally or regionally produced foods into schools in which most children eat breakfast and lunch. When implemented effectively, FTSPs offer a comprehensive way to strengthen childhood nutrition education and stimulate local communities economically and socially. They also have several other direct and indirect benefits – such as additional income for farmers and food businesses. The reviewed literature in this study shows that FTSPs can positively influence school-aged children’s nutrition knowledge, FV consumption behaviour, and awareness of farms and farmers. The studies reviewed here also show that FTSPs increase the purchase of locally produced food items, resulting in higher incomes for small farmers. FTSPs have also increased farm crop diversification, community engagement and new opportunities for farming businesses. In sum, FTSP can be considered a boon for local schools, producers, communities and better health outcomes for school-age children.

Several challenges inhibit the uptake of FTSPs, however. Key factors are food safety requirements that are prohibitively expensive for smaller producers and lack of clarity about who is liable when problems develop in the supply chain from federal and state levels. Beyond this, there are economies of scale to consider and logistics between schools and local farmers or distributors, as kitchen facilities are generally lacking at schools and small farmers cannot deliver and/or process their FVs. In several of the studies cited above, food service staff and school administrators highlight the importance of FTSPs, but stress the importance of food preparation training for staff and better ways to link themselves to local producers. There is also a need for lesson plans that integrate school gardens with nutrition education while meeting state testing requirements.

In several studies, school staff noted how students eat more FVs following the implementation of an FTSP. Strengthening food literacy enables children to develop key food-related skills such as choosing the right food at an early age, laying the foundations for lifetime healthy dietary behaviour. In addition, local producers receive social benefits and secure their economic future in an increasingly competitive context. Finally, we acknowledge that because of the diverse nature of FTSPs and the wide variety of practices within them, the wider impact of such programmes is likely to be underestimated in studies based on keywords and a literature review. Our own review paper may not be free from these limitations.