Integrating Plant-Based Diets into Schools for a Healthier and More Sustainable Future: A Contemporary Overview

Abstract

Schools constitute strategic settings for shaping eating behaviors among youth. Given the profound environmental, health, and social challenges associated with current food systems, there is an urgent need to explore dietary patterns that simultaneously support human well-being, ecological sustainability, and ethical principles. This comprehensive review provides a contemporary overview of the role of plant-based diets as an instrumental pathway to a healthier and more sustainable future by examining (i) environmental and social impacts of current food systems; (ii) the effects of plant-based diets on health; (iii) determinants of plant-based diet implementation in schools, including barriers and facilitators to their adoption; and (iv) the development of future-oriented dietary guidelines. Transitioning to plant-based diets, combined with sustainable agricultural practices, can reduce resource use and promote ecological sustainability. Promoting plant-based diets can also encourage the development of a more responsible and equitable social culture. Plant-based diets consistently provide metabolic, cardiovascular, and anti-inflammatory benefits across diverse populations, contributing to healthy weight and glycemic regulation. Well-planned plant-based diets may also improve cognitive function and promote psychological well-being. The integration of plant-based diets in schools is limited by barriers such as children’s food preferences, habitual eating patterns, peer influence, time and resource constraints, limited knowledge, cultural attachment to meat, and low family involvement. Conversely, facilitators including experiential learning, nutrition education, teacher and family engagement, social norms, ethical or environmental motivations, and institutional support promote acceptance and implementation. Ongoing research is required to refine dietary recommendations, assess long-term health outcomes, and ensure nutritional adequacy across pediatric populations. Continued evaluation of school-based interventions and policy frameworks will be essential to optimize the integration of plant-based diets and to monitor their health, ethical, and environmental impacts.

1. Introduction

Despite decades of evidence, mitigation efforts remain inadequate, with fossil fuel subsidies persisting and high-carbon diets and air pollution contributing to harmful environmental, economic, health, social, and nutritional consequences, which collectively threaten the integrity of the planet and the lives of its inhabitants [1]. To address this urgent issue, integrating sustainability into national dietary guidelines is essential, as these policy tools not only shape individual diets but also influence broader food systems and their environmental impact [2]. However, although more than 90 countries have established food-based dietary guidelines with science-based messages to promote healthy eating, sustainability and ethical concerns remain insufficiently addressed [3]. In this respect, few countries currently advise reducing meat or dairy intake, and to mitigate the environmental impact of food systems, dietary guidelines should provide clear, evidence-based recommendations that enable individuals to adopt more sustainable diets, substituting high-impact animal products with environmentally friendly alternatives, benefiting both human and planetary health [4]. Unfortunately, dietary guidelines are not neutral instruments, but rather the outcome of power dynamics between scientific, political, and industrial actors, often resulting in moral challenges regarding transparency, equity, and the distribution of responsibility [5]. Since biodiversity is pivotal to environmental health, promoting sustainable agro-ecosystem practices may help safeguard the right of all living beings to prosper within environmentally safe and healthy habitats, which possesses important implications for social development by fostering a societal model grounded in ethical and transformative principles [6]. Therefore, ensuring that dietary guidelines adequately incorporate ecological responsibility through sustainable practices is crucial, as these decisions strongly influence long-term resource use, human health outcomes, the preservation of ecosystems and biodiversity, and the legacy left for future generations.

Childhood and adolescence represent critical periods of biological and social transition, during which experiences can exert a disproportionate impact on development [7,8]. Consequently, environmental factors during these stages interact with increased social susceptibility, shaping behaviors and long-term values [9]. Schools have been regarded as powerful settings for fostering healthy eating habits among children and adolescents, as they provide continuous and prolonged access to a substantial proportion of the young population, offer operational infrastructure including policies, curricula, physical environments, and staff such as teachers who act as key agents, and also enable both individual-level and system-level interventions that can establish healthy behaviors early in life, reduce socio-economic barriers, promote critical thinking, and contribute to the prevention of chronic diseases later in adulthood [10,11,12,13,14]. Certainly, school-based interventions have been shown to improve nutritional knowledge and promote healthier dietary behaviors in both children and adolescents [10,11]. Currently, numerous school-based protocols and interventions primarily target dietary health [12,13,14]. However, integrating initiatives that promote planetary health within the school context, alongside innovative dietary programs, may present an opportunity to shape long-term food-related norms, fostering behaviors in children that consider both personal well-being and environmental sustainability [15]. In this context, the effectiveness of school-based nutrition education programs that include environmental sustainability components among school children and adolescents appears to rely on experiential activities that foster both healthy eating behaviors and pro-environmental values, whereas sustainability education alone shows limited impact [16]. Moreover, overweight and obesity affect one in five children and adolescents worldwide, representing a major global health burden due to their increasing prevalence and association with comorbidities such as depression and hypertension, further pointing to the crucial role of implementing healthy dietary patterns in pediatric populations [17]. Collectively, these considerations highlight the potential of schools as strategic settings for shaping long-term healthy dietary habits and environmental consciousness, and underscore the need for further exploration of how integrated health and sustainability programs are implemented and evaluated.

Plant-based foods represent the paradigm of health and sustainability within dietary patterns, as their increased consumption simultaneously benefits public health, mitigates climate change, and protects biodiversity by reducing reliance on animal-derived and processed foods, lowering greenhouse gas emissions, minimizing land and water use, preventing deforestation, curbing food waste, and promoting ecosystem and animal welfare [18,19]. Despite plant-based diets primarily focus on the intake of plant-based foods, they may still include meat. For this reason, vegetarian and vegan diets can be considered the most prototypical and exemplary plant-based diets because they exclude all types of animal meat, including terrestrial, aquatic, and avian. Vegetarian patterns can be classified into lacto-ovo-vegetarianism (including dairy and eggs), lacto-vegetarianism (including dairy but not eggs), and ovo-vegetarianism (including eggs but not dairy). Vegan patterns, in turn, exclude all animal-derived products [18]. Although vegetarian and vegan diets have been associated with certain nutritional deficiencies [20,21], current evidence indicates that if a nutritionally adequate diet is consumed, the avoidance of meat and other animal foods will have no significant effects on physiological and mental health [22,23]. In fact, vegetarian and vegan dietary patterns have been linked to reduced risk of cardiovascular disease, diabetes, hypertension, certain cancers, dementia, overweight, metabolic syndrome, chronic pain, ulcerative colitis, and hypercholesterolemia [24,25,26]. The health-promoting effects of these diets are partly attributable to their antioxidant, anti-inflammatory, immunomodulatory, antiproliferative, and antihypertensive properties, as well as to the ability of their components to modulate the gut microbiome (GM), thereby promoting the microbial synthesis of short-chain fatty acids (SCFAs) and postbiotics, such as equol, urolithins, enterolignans, vitamins, isothiocyanates, coprostanol, and secondary bile acids, which exert diverse beneficial effects on physiological and immunological processes [27]. Among contemporary populations, the adoption of plant-based diets has steadily increased in recent years, primarily driven by animal welfare, ethical, religious, economic, health, and environmental considerations [28,29,30,31]. This rising trend presents a unique opportunity to leverage their influence in promoting these dietary patterns among younger generations through education in high-impact settings, such as schools and family environments, thereby fostering long-term adoption of sustainable and health-promoting eating behaviors.

Given the profound environmental, health, and social challenges associated with current food systems, and considering the critical influence of childhood and adolescence education on long-term global outcomes, there is an urgent need to explore dietary patterns that simultaneously support future human well-being, ecological sustainability, and ethical principles. Plant-based diets offer an optimal approach to addressing these challenges by reducing environmental impact, promoting public health, protecting biodiversity, and aligning with societal values related to animal welfare. In this context, schools constitute strategic settings for shaping eating behaviors among youth, serving as a key tool for educating the next generation. In light of these considerations, this comprehensive review provides a contemporary overview of the role of plant-based diets as an instrumental pathway to a healthier and more sustainable future by examining (i) environmental and social impacts of current food systems; (ii) the effects of plant-based diets on health; (iii) determinants of plant-based diet implementation in schools, including barriers and facilitators to their adoption; and (iv) the development of future-oriented dietary guidelines. Ultimately, the aim of the present review is to contextualize and highlight the potential of integrating nutritional patterns focused on plant-based foods into school settings as a strategy to foster responsible dietary practices, which may contribute to long-term societal development at the global level.

2. Method

A narrative, non-systematic approach was adopted to provide a comprehensive overview of the topic under examination. Database searches were performed in PubMed, Scopus, and Web of Science between July and August 2025. The search strategy consisted of an iterative process combining keywords such as “plant-based diets”, “vegetarian diets”, “school meals”, “school interventions”, “environmental impact”, “sustainability”, “dietary guidelines”, “barriers”, “facilitators”, “health effects”, and “pediatric health”. No restrictions or filters were applied regarding publication date, study type, or language. In addition, previously identified relevant articles were included, and reference lists from pertinent studies were examined to identify further significant sources. The selection process involved two stages. First, titles and abstracts were screened to exclude studies not aligned with the central research focus. Second, full texts of the remaining articles were examined in detail. Inclusion criteria prioritized studies addressing the role of plant-based diets in schools, their environmental, social, and health impacts, and also determinants of their implementation, including barriers and facilitators. Exclusion criteria included studies without accessible full texts, conference abstracts, letters, theses, and research not directly or indirectly addressing plant-based diets or their implications. Extracted data were then thematically synthesized to structure the review, providing a cohesive and contextually relevant compilation of current knowledge.

3. Environmental and Social Impacts of Current Food Systems

3.1. Environmental Implications

Feeding a growing global population intensifies environmental challenges, which are closely linked to current food production systems driving climate change, land-use change, freshwater depletion, biodiversity loss, food waste, and ecosystem pollution. Without mitigation, these impacts could rise 50–90% by 2050, surpassing planetary boundaries [32]. In fact, even the lowest-impact animal products generally exceed the environmental footprint of plant-based alternatives, reinforcing the necessity of dietary shifts [33]. In 2015, the food system contributed 18 gigatons of carbon dioxide equivalent (Gt CO₂e) annually (about 34% of total global emissions), with agriculture and land-use change accounting for the majority (71%), fundamentally driven by animal production, while the rest coming from supply chain activities such as retail, transport, waste management, and packaging [34].

These environmental pressures extend beyond climate and resource use, impacting biodiversity and ecosystem integrity. Global analyses of fauna extinctions indicate that human arrival was the primary driver, with climatic factors playing only a minor, region-specific role, but not being the main cause [35,36,37]. Carnivore dietary patterns among humans threaten around one-quarter of vertebrate species [38]. Human predation, including hunting, fishing, and livestock production, exerts far stronger impacts on ecosystems than other top predators [39,40,41]. Moreover, domesticated and translocated animals affect native species through competition, disease transmission, and genetic hazards, contributing to ecological extinctions and biodiversity decline [38]. In turn, animal agriculture drives extensive environmental degradation, including about 85% of South American rainforest loss for grazing and feed crops, overuse of nitrogen and phosphorus fertilizers causing eutrophication and ocean acidification, a 68% decline in monitored vertebrate populations over the last 50 years, unsustainable water use with beef accounting for 22% of United States agricultural water and 55% in the Colorado River basin, and large-scale fishing with 27% of global catch directed to feed farmed animals, all contributing to ecosystem collapse [42].

Animal-based foods entail massive food losses, since plant-based alternatives provide far more nutrition per cropland. For instance, losses reach 96% for beef and 90% for pork, and replacing all animal products in the United States with plant-based alternatives could feed 350 million additional people, far exceeding the gains from eliminating all supply chain food waste [43]. These opportunity losses not only reduce the efficiency of our food system but also exacerbate environmental pressures, as producing resource-intensive animal products requires disproportionately more land, water, and energy compared with nutritionally equivalent plant-based foods.

The transition toward a plant-based world offers multiple benefits in counteracting the negative effects of animal agriculture. This shift can contribute to environmental restoration by reducing resource consumption and greenhouse gas emissions. At the same time, it supports ethical improvements by alleviating animal exploitation and enhances human well-being through healthier dietary choices and improved working conditions within the food system [44]. While mitigation strategies can exist throughout the supply chain, producers could face limits to how much they can reduce impacts. Effective solutions may require monitoring environmental footprints, adopting flexible practices to meet sustainability targets, and communicating progress to consumers. Complementing these actions with dietary shifts toward plant-based foods can further reduce reliance on high-impact animal agriculture and ease pressure on natural resources. These strategies align with ongoing research on food system transformations, which seeks to understand and guide comprehensive, equitable, and sustainable changes across the entire food system, emphasizing practical pathways to achieve healthy and sustainable outcomes [45].

In order to address the transition toward plant-based diets and reduce the environmental footprint of food production, it is also necessary to implement sustainable agricultural practices that enhance resource efficiency and ecosystem stability. An imbalance in land use can destabilize ecosystems, and disparities in food production continue to challenge global food security [46]. Strategies to mitigate these environmental pressures include improving nitrogen fertilizer management, optimizing feed and energy use, enhancing irrigation efficiency, and adopting alternative agricultural practices [47,48,49,50]. The use of grain-system by-products as feed has been shown to reduce both water and land footprints and alleviate competition between food and feed, supporting the UN 2030 food security goals [51]. In addition, the implementation of biopesticides, organic nitrogen fertilizers, clean energy, and climate-smart technologies contributes to lowering the carbon, water, and nitrogen footprints of crop production [52,53,54]. Building on the aforementioned strategies, diversified agricultural systems offer further opportunities for sustainability. Approximately 47% of global regions, particularly in the Northern Hemisphere, are suitable for profitable diversification [55]. Practices such as crop rotation, intercropping, straw returning, cover cropping, and integrated systems, including livestock–plant and crop–livestock–bioenergy approaches, have been empirically demonstrated to reduce carbon and nitrogen footprints [56,57,58,59,60,61]. The effectiveness of these strategies, however, depends on crop type, geographic conditions, and the adoption of appropriate agricultural technologies.

As dietary patterns increasingly shift toward plant-based consumption, the demand for large-scale crop production is expected to rise. This transition emphasizes the urgent need to decouple land productivity from environmental footprints, ensuring that increased crop production does not compromise ecosystem health. In this respect, research has focused on optimizing farming methods, management practices, and resource use through field experiments, model simulations, and data envelopment analysis, all aimed at maintaining yields while reducing environmental impacts [62,63]. Within this context, the role of organic farming is complex. Meta-analyses suggest that under optimal management, crop selection, and favorable growing conditions, organic systems can achieve yields comparable to conventional systems [64]. Conversely, some studies report substantially lower yields, such as 45.9% less wheat compared to conventional farming [65]. Thus, both conventional and organic systems face environmental challenges, including the acidification and depletion of abiotic fossil fuel resources [66]. Importantly, Lombardi et al. [67] demonstrate that a 50% reduction in animal protein intake aligns the land footprint of organic agriculture with conventional systems. This finding underscores the critical role of reducing animal protein consumption and adopting plant-based diets as a strategy to enhance agricultural sustainability and minimize environmental impacts.

Overall, transitioning toward plant-based diets emerges as a pivotal strategy for mitigating the environmental pressures of current food systems. Coupled with sustainable and diversified agricultural practices, optimized resource use, and reductions in animal protein consumption, this shift can balance the need to feed a growing population with the imperative to preserve ecosystems, maintain biodiversity, and reduce greenhouse gas emissions. Therefore, integrating dietary changes with agricultural innovation provides a transformative pathway toward a more adaptive, efficient, and responsible global food system.

3.2. Social Implications

The normalization of animal exploitation in dietary practices can desensitize individuals to violence, potentially fostering a culture where aggression is more readily accepted. Indeed, the routine exposure to animal suffering in conventional agriculture diminishes empathy and emotional responsiveness, reinforcing societal tolerance for harm and linking attitudes toward animals with broader acceptance of violence, a process compounded by the systemic nature of factory farming [68]. This process has been further reinforced by the historical erosion of legal protections for farmed animals, which were initially among the first to be covered by anti-cruelty statutes but have since been systematically excluded through exemptions that shield standard agricultural practices from scrutiny. As farming shifted from small-scale household production to corporate industrial systems, this legal gap enabled unprecedented levels of suffering to become institutionalized, creating what some scholars have described as a crisis of animal suffering comparable in scale to other forms of mass social harm [69].

Violence toward animals and humans are interconnected, with animal abuse serving as a strong but not definitive predictor of human-directed violence [70]. In this respect, individuals who engage in animal cruelty are more likely to exhibit violent behaviors toward humans, suggesting a psychological link between the two forms of violence. Research has reported that some public mass and active shooters have histories of animal abuse, with such offenders tending to be younger, less likely to die at the scene, and more likely to harm multiple victims [71]. Similarly, domestic abusers often harm companion animals to exert psychological control over victims, with the mistreatment of animals contributing to the maintenance of abusive environments and influencing the decisions of victims to remain in these settings [72]. In addition, slaughterhouse employment has been consistently associated with negative psychosocial outcomes, as these workers show higher rates of depression, anxiety, antisocial behavior, sexual offending, and violence-supportive attitudes compared to other populations [73].

Given that large-scale domestication and exploitation of animals is associated with systemic violence, social oppression, zoonotic disease outbreaks, resource appropriation and depletion, population displacement, and contributions to contemporary global crises such as hunger, environmental degradation, and climate change [74], it is plausible to assert that the normalization of mass animal slaughter represents a highly influential factor in shaping attitudes among young populations. Childhood and adolescence constitute critical periods of social and moral development, during which values, ethical frameworks, and behavioral norms are established. Once internalized, these early-acquired patterns are often resistant to modification later in life. Within this developmental context, schools serve as primary sites for both the socialization of normative behaviors and the manifestation of peer-to-peer violence, including bullying, a prevalent phenomenon with profound psychosocial consequences [75]. Exposure to normalized violence against animals may exacerbate these dynamics by reinforcing aggressive and desensitized behavioral tendencies, creating a social context in which both general bullying and more targeted forms, such as ethnic-cultural bullying, are more likely to occur. Ethnic-cultural bullying involves the marginalization or devaluation of peers on the basis of perceived racial or cultural differences [76], processes closely linked to cognitive and affective mechanisms of dehumanization. Drawing a parallel to attitudes toward animals, the habitual witnessing or acceptance of cruelty toward nonhuman beings may contribute to the cognitive framing of out-group human peers as less morally salient or deserving, thereby amplifying tendencies toward interethnic aggression. In this manner, the societal normalization of violence against animals is not merely an ethical concern regarding nonhuman life but may also constitute an indirect but potent factor in the propagation of socialized violence and dehumanization among young people, with implications for educational policy, school-based intervention, and systemic social development.

Based on the aforementioned, schools and familial influence represent highly promising frameworks for fostering more equitable societal values, particularly regarding attitudes toward animals. By integrating ethical education, critical thinking about dietary practices, and awareness of the consequences of animal exploitation, educational settings can intervene during critical developmental periods to counteract normalized patterns of violence and desensitization. Moral reasoning is crucial for both individual development and societal change. From childhood to adulthood, it drives age-related improvements in evaluating fairness, equality, and need, guiding actions to rectify inequalities and resist stereotypes. Beyond personal development, moral reasoning enables individuals to identify and challenge social injustices, contributing to long-term societal transformation [77]. When combined with parental discipline methods [78], moral reasoning can cultivate empathy, prosocial behavior, and an inclusive ethical orientation that encompasses both human and nonhuman beings. Importantly, by shifting toward plant-based diets, societies can challenge rooted behaviors and cultural norms that reinforce cruelty, thereby promoting empathy and reducing the acceptance of violence in all its forms. Thus, schools are not merely sites of academic instruction but pivotal contexts for shaping future generations capable of sustaining more humane, just, and socially responsible communities.

4. The Effects of Plant-Based Diets on Health

4.1. Plant-Based Diets in Physiological Health

Plant-based dietary patterns, characterized by high intakes of fruits, vegetables, legumes, whole grains, nuts, and seeds, have been associated with favorable metabolic, inflammatory, and cardiometabolic profiles. Indeed, a range of recent studies (2022–2025) have consistently demonstrated that plant-based diets exert beneficial effects across a range of health-related outcomes, including weight management and body composition [79,80,81,82,83,84], glycemic control and diabetes [85,86,87], cardiovascular health and lipid profiles [88,89,90,91,92,93,94], and muscle function and protein metabolism [95,96,97,98]. In addition, a recent prospective cohort study with 9301 participants investigated whether plant-based dietary intake moderates the association between adverse childhood experiences (ACEs) and early mortality [99]. Results indicated that individuals with high plant-based intake could potentially live 5.4 years longer than those with low intake after experiencing 4 or more ACEs, suggesting that plant-based diets may mitigate the long-term mortality risks associated with childhood adversity.

4.1.1. Metabolic, Glycemic, and Cardiovascular Benefits

Interventions addressing type 2 diabetes mellitus (T2DM) and obesity reported substantial weight reduction and metabolic improvements, including decreased glycated hemoglobin (HbA1c), reductions in low-density (LDL) and high-density lipoproteins (HDL), and diminution of total cholesterol (TC) levels, after adopting plant-based diets compared to omnivorous diets [100,101,102]. For instance, Lee et al. [103] reported decreased HbA1c levels and reduced waist circumference in vegan diet groups, while Jenkins et al. [104] observed disease-attenuating effects in patients with hyperlipidemia after six months on a low-carbohydrate plant-based diet compared to a high-carbohydrate lacto-ovo-vegetarian diet. Although lower energy intake in vegans may contribute to these effects, other studies controlling for caloric intake still demonstrated trends toward enhanced metabolic outcomes. Two studies in T2DM patients comparing calorie-unrestricted vegan or vegetarian diets with calorie-restricted conventional diets over 6 months to 1.5 years (N = 86) showed greater improvements in body mass index (BMI), glucose and insulin sensitivity, and reduced medication requirements with plant-based diets [105,106]. Plant-based interventions recently conducted have similarly yielded favorable effects in T2DM management. In the Marshall Islands, a 24-week whole-food plant-based (WFPB) diet with moderate exercise reduced HbA1c, medication use, weight, and inflammation, and achieved diabetes remission in 23% of participants with baseline HbA1c <9% [86]. Short-term interventions, such as Mankai-supplemented meals, decreased postprandial glucose excursions and improved triglyceride/HDL ratios [87], while long-term increases in plant protein intake were associated with higher likelihood of diabetes remission independent of weight loss [85].

A five-arm study evaluating vegan, vegetarian, pesco-vegetarian, semi-vegetarian, and omnivorous diets among obese subjects (N = 63) found that the vegan diet produced the most substantial weight reduction (−7.5% to −4.5% of total body weight) and decreased inflammatory markers, measured by the dietary inflammatory index [107]. These effects occurred despite comparable caloric intake across groups, suggesting that plant-based diets exert health benefits beyond simple caloric restriction. Nevertheless, a conceptual limitation of the study lies in the categorization of dietary patterns. In this respect, vegan and vegetarian diets are strictly defined as excluding products derived from animal slaughter. Consequently, when interpreting broader trends across vegetarian and non-vegetarian diets, the inclusion of pesco-vegetarian and semi-vegetarian categories does not represent strictly plant-based dietary patterns. Consistent with these findings, recent interventions adopting plant-based dietary patterns, particularly whole-food, low-fat, or vegan diets, have consistently demonstrated improvements in body weight, metabolic markers, and glycemic control across diverse populations. For instance, a 10-week WFPB program in New Zealand involving 56 adults with obesity and elevated HbA1c led to reductions in weight (mean −5 kg), BMI, HbA1c, and TC, with partial maintenance of weight loss at 36 months [83]. Similarly, a 16-week trial of 244 overweight adults showed that a vegan diet increased adherence to plant-based diet indices, which correlated with weight loss [82]. Longer-term, culturally customized interventions among African American adults with overweight or obesity reported modest but sustained weight reductions and improved nutrient intake with vegan diets, comparable to low-fat omnivorous diets [81,84]. Targeted low-fat vegan dietary patterns also reduced fat mass, body weight, insulin resistance, and inflammatory markers, with legume consumption identified as a strong predictor of weight loss [79,80].

Even brief interventions emphasizing plant foods improved lipid profiles and cardiometabolic parameters in healthy adults and populations with chronic conditions [90,91]. Cardiovascular benefits were further observed with specific plant foods, including walnuts, vegetarian, and Mediterranean diets, which improved lipid and GM profiles, and also lowered blood pressure [89,93,94]. Emerging evidence also supports anti-inflammatory and stroke-protective effects of plant-based diets, demonstrated by reductions in periodontal inflammation and stroke-associated metabolites [88,92]. Therefore, plant-based dietary patterns can support weight management, metabolic health, glycemic control, and cardiovascular protection, with intervention design, dietary adherence, and specific food components influencing the magnitude of benefits.

4.1.2. Muscle Function and Proteins

Recent controlled trials indicate that well-planned plant-based diets and plant-derived proteins can support muscle function and anabolic responses comparable to omnivorous diets across age groups. In a 10-day crossover study with 34 older adults (mean age 72 years), a varied vegan diet maintained daily mixed muscle protein synthesis rates similar to an isocaloric, isonitrogenous omnivorous diet, while also lowering LDL, HDL, and TC without affecting triglycerides, glucose, insulin, insulin resistance, or blood pressure [95]. Similarly, in a randomized double-blind trial of 36 healthy young males (mean age 26 years), ingestion of 30 g corn protein alone or combined with 15 g milk protein stimulated post-prandial myofibrillar protein synthesis to a comparable extent as 30 g milk protein, demonstrating that plant proteins can be equally anabolic when appropriately dosed [97]. These findings collectively suggest that age and protein source do not necessarily limit the capacity of plant-based proteins to support muscle maintenance and synthesis.

Beyond anabolic responses, plant-based diets and meat alternatives may confer ancillary benefits for kidney function and hydration. In an 8-week randomized crossover trial, consumption of plant-based meat compared with animal meat in generally healthy adults lowered urinary excretion of sulfate, ammonium, phosphorus, and urea nitrogen, increased urinary pH and citrate, and modestly reduced serum creatinine, suggesting potential kidney health benefits of plant-meat diets [98]. In addition, a study comparing 1000 mL of skimmed cow’s milk versus a sweetened soya beverage in 10 healthy males showed no differences in total urine output or hydration markers, with potassium balance higher following soya intake, indicating that soy-based drinks provide comparable hydration to dairy [96]. Together, these studies highlight that plant-derived proteins and protein-rich beverages can promote muscle function and also offer kidney and hydration benefits, making them viable alternatives across age groups and health contexts.

Plant-based animal product alternatives (PB-APAs) have emerged as tools to reduce animal product consumption while maintaining sensory and culinary experiences. PB-APAs, such as Beyond Meat and Oatly, mimic the appearance, taste, smell, and functionality of animal products, emphasizing consumer needs for taste, familiarity, and convenience [108,109]. Evidence shows that PB-APAs can aid in reducing meat intake without compromising diet satisfaction and also exhibit favorable environmental profiles compared to animal products, including lower greenhouse gas emissions, water usage, and land use [110,111]. Nutritionally, PB-APAs support weight management, muscle synthesis and maintenance, and also meet the needs of specific health conditions [112]. These PB-APAs can thus serve as practical sources of protein, offering additional nutritional and environmental benefits.

4.1.3. Nutrient Composition and Mechanistic Effects

The nutrient composition of plant-based diets differs markedly from omnivorous diets, with variations in micro- and macronutrients affecting multiple physiological pathways. These differences challenge the attribution of metabolic benefits to a single dietary component. Instead, plant-based diets may act through multiple mechanisms, including enhanced glycemic control [113], reduced inflammatory activity [114], and modulation of neurotransmitter metabolism via dietary intake [115] or gut activity [116]. Indeed, significant disparities exist in macronutrient profiles between dietary patterns. Plant-based diets are generally higher in mono- and polyunsaturated fatty acids, fibers, and complex carbohydrates. Conversely, they are lower in saturated and trans fats, refined sugars, proteins, and cholesterol [117]. Micronutrient intake also differs, as vegans consume less retinol, vitamin B12, vitamin D, calcium, and zinc, while intake of magnesium, iron, folic acid, and vitamins B1, C, and E is higher compared to omnivorous diets [118,119,120]. Saturated fat content and origin may be particularly relevant, as higher intake can elevate systemic lipid levels and cardiovascular risk [121,122].

A key characteristic of plant-based diets is high dietary fiber from legumes, grains, vegetables, and fruits, which promotes favorable metabolic processes including enhanced carbohydrate fermentation, reduced protein fermentation [123,124], improved appetite regulation via gut hormones [125,126,127,128,129], and potential prevention of chronic diseases such as obesity and T2DM by slowing digestion and improving lipid control [130]. A review of 185 prospective studies and 58 clinical trials indicated that daily fiber intake of 25–29 g significantly reduces the risk of cardiovascular disease, T2DM, and stroke [131]. More recent evidence suggests short-term high-fiber diets enhance satiety, improve metabolic parameters, suppress postprandial acylated ghrelin, and maintain resting energy expenditure [132], while also inducing microbial changes that may reduce long-term weight gain [133].

The lower systemic inflammation observed in plant-based diet adherents may result from increased anti-inflammatory molecules and avoidance of pro-inflammatory, animal-derived molecules [134]. This is particularly relevant in obesity, a condition associated with elevated cardiovascular risk [135]. Higher levels of C reactive protein (CRP) and interleukin-6 (IL-6) have been linked to alterations in brain microstructure and increased cognitive decline risk [136,137,138]. In this respect, diets with low inflammatory indices may directly promote healthy brain aging [139]. Plant-based diets are also rich in phytochemicals and vitamin C from fruits and vegetables, which may enhance immune function and protect against chronic diseases [140]. Meta-analyses suggest benefits on cardiovascular disease, cancer, overweight, body composition, glucose tolerance, digestion, and mental health [141]. Other compounds excluded from plant-based diets, such as opioid peptides from casein, carry-over antibiotics in animal products, or dietary toxins like dioxins and nitrosamines, may further explain indirect health benefits of plant-based patterns [142,143,144,145,146].

4.1.4. Interventions in Pediatric Populations

In the context of pediatric populations and educational settings, various studies have investigated the impact of plant-based or nutritionally optimized dietary programs. A randomized trial involving 107 children with abdominal obesity demonstrated that an intensive lifestyle program combining a moderately hypocaloric Mediterranean diet with nutritional education increased adherence to the EAT-Lancet planetarian diet and led to reductions in BMI, weight, and waist circumference, highlighting the potential of early adoption of plant-forward diets to support healthy weight trajectories and align with sustainable dietary patterns [147]. Similarly, a large-scale program conducted in Australia, including 1001 children, aimed to increase fruit and water intake while reducing unhealthy food and beverage consumption. Participants exhibited smaller increases in body weight, waist circumference, and BMI z-scores compared to a regional comparison group, with no evidence of exacerbated health inequalities [148]. Apart from pediatric populations, a 4-week “Plant Plunge” challenge in higher education settings with 46 medical students from the United States resulted in significant reductions in weight and blood pressure and enhanced understanding of diet–health relationships, underscoring the potential of integrating plant-based programs into educational curricula to promote healthy eating behaviors and internalization of sustainable dietary patterns [149]. Evaluating the nutritional quality of school meals in Seoul, Kim and Kim [150] reported that plant-based menus in elementary schools provided lower energy, protein, fat, thiamine, and vitamin C, but higher carbohydrates, calcium, and iron compared to regular menus, with macronutrient distributions largely within recommended ranges. Nevertheless, it was reported that some plant-based menus failed to meet nutritional standards for certain nutrients. In turn, a garden-based intervention conducted by Davis et al. [151] in the United States noted improved dietary behaviors and vegetable intake without significant effects on obesity or blood pressure. The results obtained in these studies suggest that plant-based interventions within educational settings can promote healthier dietary patterns and potentially exert positive health-related outcomes, but careful attention to nutrient adequacy is completely essential.

Table 1. Effects of plant-based diets on pediatric body composition and physiology.

Reference	Intervention	Results/Outcomes
Alexy et al., 2021 [152]	Germany. Cross-sectional. N = 149 Veg, N = 115 VE, and N = 137 OM (6–18 years old). Mean age: 12.7 years.	Veg and VE children showed generally adequate nutritional status compared to OM. VE participants had higher folate and lower LDL-C/non-HDL-C, while Veg exhibited lower holotranscobalamin and higher methylmalonic acid. Ferritin was highest in OM. Overall, no major nutritional risks were observed among Veg or VE youth.
Ambroszkiewicz et al., 2011 [153]	Poland. Cross-sectional. N = 30 Veg (4–10 years, 18 males, 12 females): 15 LOV since birth, 2 LV, 9 OV, 4 VE. Control group: N = 60 OM	Veg exhibited normal height, weight, and lean/fat body mass, with lower fat mass than OM. Blood lipids were within physiological ranges, with total cholesterol, LDL, and triglycerides lower in Veg. Leptin levels were approximately halved, and adiponectin levels were higher compared to OM.
Ambroszkiewicz et al., 2018 [154]	Poland. Cross-sectional. N = 62 Veg, and N = 55 OM (5–10 years old).	Veg and OM children were comparable in age, weight, height, BMI, and body composition. Veg had lower leptin/soluble leptin receptor ratios and resistin levels, with higher anti-inflammatory to pro-inflammatory adipokine ratios. Other adipokines were similar between groups.
Ambroszkiewicz et al., 2023 [155]	Poland. Cross-sectional. N = 51 Veg, and N = 25 OM (4–9 years old).	BMI did not differ between Veg and OM. Veg showed 10–15% lower serum levels of valine, lysine, leucine, and isoleucine, slightly lower (but normal) serum albumin, higher CTX-I, and no differences in other bone metabolism markers or PTH.
Desmond et al., 2021 [156]	Poland. Cross-sectional. N = 63 Veg, N = 52 VE, and N = 72 OM (5–10 years old).	VE diets were linked to a healthier cardiovascular profile but higher risk of nutritional deficiencies, lower bone mineral content, and shorter height. Veg had fewer deficiencies but a less favorable cardiometabolic profile.
Elliot et al., 2022 [157]	Canada. Longitudinal. A total of 8907 children aged 6 months to 8 years, including N = 248 Veg at baseline, participated. Mean age at baseline was 2.2 years.	Veg diets showed no association with zBMI, height-for-age, ferritin, vitamin D, or serum lipids. Veg children had higher odds of underweight. Milk intake influenced cholesterol levels but children meeting the recommended 2 cups/day had similar serum lipids.
Gorczyca et al., 2011 [158]	Poland. Cross-sectional. N = 24 Veg (2–18 years, 6 males, 18 females): 2 VE, 10 LOV, 7 LV or OV, 5 SV; all on Veg diet for at least 1 year, no allergies, no use of nutritional supplements. Control group: 16 OM with allergies, 18 OM without allergies.	Veg had similar height, weight, and most blood lipids to omnivores. Linoleic acid was higher and eicosapentaenoic acid lower in Veg compared to allergic OM.
Gorczyca et al., 2013 [159]	Poland. Cross-sectional. N = 22 Veg children (2–18 years, 5 males, 17 females): 11 LOV, 6 LV, 5 SV; all on a Veg diet for at least 1 year, no use of Fe supplements; mainly parents also were Veg. Control group: 18 OM	Veg had similar height and weight to OM but showed higher prevalence of iron deficiency (serum ferritin 9.6 μg/L vs. 36.1 μg/L) and a negative correlation between age and iron intake.
Hovinen et al., 2021 [160]	Finland. Cross-sectional. N = 10 Veg, N = 6 VE, and N = 24 OM children (mean age 3.5 years old).	VE participants exhibited vitamin A insufficiency and borderline vitamin D levels, along with low total, HDL, LDL cholesterol, essential amino acids, and DHA. Metabolomic profiles, bile acid biosynthesis, and phospholipid balance differed from OM.
Jen et al., 2018 [161]	The Netherlands. Prospective cohort. N = 3991. Age 8–10 years old.	Higher protein intake at age 8 was linked to increased risk of overweight/obesity up to age 10, mainly via higher FFMI rather than FMI. Both plant and animal protein increased FFMI, with plant protein showing a stronger effect. Higher plant protein intake was associated with lower FMI, while higher animal protein intake trended toward higher FMI.
Laskowska-Klita et al., 2011 [162]	Poland. Cross-sectional. N = 32 Veg (2–10 years, 18 males, 14 females): 21 LOV, 1 LV, 5 OV, 5 VE Control group: 18 OM.	Iron status (Fe, total iron-binding capacity, ferritin, transferrin) and vitamins B12, A, and E were within physiological ranges in Veg. Homocysteine (5.79 μmol/L) and vitamin A (1.25 μmol/L) were similar to OM, while vitamin E and overall antioxidant status were slightly lower. Vitamin D levels (13.7 μg/L) were approximately half the reference limit.
Matthews et al., 2011 [163]	The United States. Prospective cohort. N = 1764 SDA and OM children (879 males, 885 females, 6–18 years). No control group	17% of boys and 20% of girls were overweight in both groups. Higher nut and vegetable intake was associated with lower overweight risk, while higher dairy intake was positively associated. No significant associations were observed for meat, fish, eggs, or fruit consumption.
Rowicka et al., 2023 [164]	Poland. Cross-sectional. N = 32 LOV, and N = 40 OM (2–10 years old).	Children on a LOV diet showed lower TOC, GSH, and GSSG, but higher TAC compared to OM. OSI was lower in LOV, while GSH/GSSG ratio, CRP, and calprotectin were similar between groups. Correlations indicated maintained oxidant–antioxidant balance in LOV children.
Světnička et al., 2022 [165]	Czech Republic. Cross-sectional. N = 79 Veg, N = 69 VE, and N = 52 OM (0–18 years).	No differences were observed in holotranscobalamin, folate, homocysteine, or mean corpuscular volume. Cyanocobalamin (B12) levels differed, with few children showing deficiency but many exhibiting B12 hypervitaminosis (Veg: 35, VE: 28, OM: 9). Supplementation significantly affected B12, aB12, and homocysteine levels.
Světnička et al., 2023 [166]	Czech Republic. Cross-sectional. N = 91 Veg, N = 75 VE, and N = 52 OM (0–18 years old). Stratified analyses were performed based on age: 0–5 years and 6–18 years.	VE and Veg children showed a trend toward lower UIC than OM, indicating a potentially higher risk of iodine deficiency. Further research is needed to assess long-term effects on iodine status and thyroid function.
Weder et al., 2019 [167]	Germany. Cross-sectional. N = 127 Veg, N = 139 VE, and N = 164 OM (1–3 years old).	Energy intake, energy density, and anthropometrics were similar across groups. OM children consumed more protein and added sugars, while VE children consumed more carbohydrates and fiber, indicating that Veg and VE diets can support normal growth comparable to OM children.

BMI: body mass index, CRP: C-reactive protein, DHA: docosahexaenoic n-3 fatty acid, FFMI: fat-free mass index, FMI: fat mass index, GSH: reduce glutathione, GSSG: oxidized glutathione, HDL: high density lipoprotein, LDL: low density lipoprotein, LOV: lacto-ovo vegetarians, LV: lacto-vegetarians, OM: omnivore, OSI: oxidative stress index, PTH: parathormone, TAC: total antioxidant capacity, TOC: total oxidant capacity, UIC: concentration of iodine in spot urine, VE: vegan, Veg: vegetarian.

presents several studies on the relationship between vegetarian and vegan diets and their effects on body composition development and physiological parameters in children and adolescents.

Cross-sectional and cohort studies examining the physiological and nutritional status of vegetarian and vegan children have generally reported normal growth and body composition compared to omnivores. The Vechi Youth Study [152] found no significant differences in hemoglobin, vitamin B2, 25-OH vitamin D3, HDL-C, or TG between diet groups, although ferritin was higher in omnivorous and vegans had the lowest non-HDL-C and LDL-C. Ambroszkiewicz et al. [153,154,155] observed that vegetarian children had normal height, weight, and lean body mass, lower fat mass, improved blood lipid profiles, favorable adipokine ratios, slightly lower essential amino acids, and higher bone resorption markers, without major differences in BMI or other bone metabolism markers compared to omnivores. Desmond et al. [156] noted that vegan diets were associated with healthier cardiovascular profiles but also with increased risk of micronutrient deficiencies and lower bone mineral content. Longitudinal analyses [157,161,163] indicated that vegetarian and vegan diets generally supported normal growth trajectories, with higher plant protein intake favorably associated with fat-free mass and lower fat mass, and no major impact on BMI or overweight risk. Interestingly, an inverse association has been observed between plant-based food consumption and the risk of overweight in children and adolescents, which may be explained by factors such as a higher resting metabolic rate, greater satiety leading to reduced intake of other foods, and incomplete energy absorption from plant sources [163]. However, some micronutrient deficiencies (vitamin B12, vitamin D, iron, iodine) were noted in subgroups [159,160,162,165,166]. Finally, vegetarian and vegan children tended to have higher fiber and lower fat intakes, lower oxidative stress indices, and balanced antioxidant status compared to omnivores peers [164,167]. Building on these findings, it is plausible to assert that well-planned plant-based diets during childhood can provide a favorable framework for growth, metabolic health, and long-term disease prevention, highlighting the importance of dietary planning, nutrient monitoring, and education for families choosing plant-based patterns.

4.2. Plant-Based Diets and the Gut Microbiome

Another pivotal mechanistic pathway through which plant-based diets may influence health involves the GM, an area of increasing scientific interest [27]. A commonly used method to characterize the GM is enterotyping, which stratifies individuals based on the relative abundance of bacterial genera, such as Prevotella and Bacteroides [168]. Despite the limited number of controlled interventional trials, this ratio has been shown to differentiate microbial profiles associated with plant-based versus animal-based diets [169]. Specifically, in a sample of 98 individuals, Wu et al. [169] reported that diets high in protein and animal fats were associated with increased Bacteroides abundance, whereas carbohydrate-rich diets, typical of plant-based patterns, were linked to higher Prevotella levels. In addition, a dietary shift from a high-fat/low-fiber to a low-fat/high-fiber regimen induced changes in GM enterotypes within 24 h, persisting over 10 days, although not fully transitioning to an alternate enterotype [169].

In a strictly controlled 30-day crossover study, dietary interventions with exclusively animal- or plant-based diets promoted GM diversity and modulated gene expression within five days [124]. This effect was particularly pronounced with the animal-based diet, which elicited a rapid increase in microbial diversity, surpassing baseline levels of microbial gene expression. Evidence from two randomized controlled trials indicates that even minimal dietary modifications, such as daily consumption of 43 g of walnuts, can lead to an increase in probiotic- and butyric acid-producing bacterial species after three and eight weeks, respectively [170,171].

The Prevotella-to-Bacteroides (P/B) ratio appears to influence the effectiveness of dietary interventions targeting weight reduction. Individuals with a higher P/B ratio experienced greater weight loss on a 6-month whole-grain diet compared to those with lower ratios [172]. Other microbial communities, including the salivary microbiome, have also been shown to differ between omnivores and vegan subjects [173], suggesting additional avenues for research on diet-mediated microbiome adaptation [174].

Evidence suggests that plant-based diets are associated with distinct gut microbial profiles. Vegan diets, in particular, show marked differences compared to omnivorous diets, though not necessarily when compared with vegetarian diets [175]. In a small study of six obese individuals following a one-month vegetarian diet, reductions in pathobionts, increases in protective bacterial species, improved lipid metabolism, and decreased intestinal inflammation were observed [176]. Long-term observational studies have demonstrated dose-dependent shifts in GM composition in vegetarians and vegans compared to omnivores, with decreased abundance of Bacteroides, Bifidobacterium, Escherichia coli, and Enterobacteriaceae, most pronounced in vegans [177]. The functional significance of these compositional changes remains unclear, requiring further development of functional microbiome analyses.

Fermentation processes associated with fat and carbohydrate metabolism have been linked to the abundance of specific microbial species. Notably, fiber intake correlates strongly with Prevotella abundance [124], which has been associated with plant-based and low-fat/high-fiber diets [178,179], and may promote SCFA production [180]. SCFAs serve as signaling molecules interacting with host receptors, such as free fatty acid receptor 2, expressed across multiple tissues [129,181], potentially mediating GM-host communication via the gut–brain axis. Although the specific mechanisms and health implications of Prevotella remain under investigation, increased fiber intake and subsequent Prevotella proliferation in plant-based diets may support glycemic regulation and moderate inflammatory processes, partially via enhanced satiety and reduced energy intake [182].

A Green-Mediterranean diet, which is characterized by high intakes of plant foods, walnuts, green tea, and the aquatic plant Mankai, has been shown to induce more pronounced GM alterations than a conventional Mediterranean diet, particularly in low-abundance “non-core” microorganisms. These changes included increases in Prevotella and branched-chain amino acid degradation pathways, and decreases in Bifidobacterium and branched-chain amino acid biosynthesis pathways. Improvements in body weight and cardiometabolic biomarkers were observed, with the magnitude of benefit linked to adherence and specific plant-based components of the diet. Notably, GM shifts appeared to mediate the relationship between dietary adherence and cardiometabolic improvements [183]. Furthermore, the GM may also influence systemic homeostasis, suggesting a role in whole-body regulatory mechanisms. Emerging GM-based therapeutic strategies aim to improve glycemic control and other physiological parameters by inducing microbial changes that affect systemic homeostasis, potentially including effects at the central nervous system level [184]. This concept has been further explored in the context of bidirectional interactions between the GM and the brain, with diet playing a potential role in the onset and progression of various mental disorders [185].

4.3. Plant-Based Diets in Mental Health

Divergent evidence has been reported on the prevalence or risk of mental health conditions, such as depression, anxiety, and stress, regarding the adoption of a plant-based diet [186]. Positive associations among vegetarian and vegan participants were observed in several studies [187,188,189,190,191,192], whereas other studies reported the opposite [193,194,195,196]. In addition, no clear vegetarian or vegan diet-related effects on mental health or mood have also been reported [197,198,199,200,201,202]. Research on specific populations following a plant-based diet has also shown irregular findings, with some trends indicating poorer mental health outcomes [203,204] and other revealing benefits in certain domains [205,206]. Within this context, it has been suggested that deficiencies in essential amino acids, such as methionine, tryptophan, or tyrosine, may underlie the link between plant-based diets and depression via dopamine and serotonin metabolism [207]. On the other hand, the association between vegetarianism and mental health may be driven more by psychological mechanisms than by diet itself [186]. In this respect, mental health conditions could also motivate individuals to adopt a vegetarian diet as a form of self-protection, perceived as healthier. Matta et al. [202] reported that depression risk was associated with exclusion of any food group, indicating that links between vegetarian diets and depression may reflect a broader relationship between depressive symptoms and food exclusion, independent of food type. Moreover, these authors demonstrated that the association between vegetarian diets and depression varied with legume intake, weakening as consumption increased [202]. Given that legumes are a rich protein source, this supports the hypothesis that well-planned vegetarian diets may be less associated with depressive symptoms and are nutritionally adequate. Nevertheless, economically disadvantaged individuals avoiding meat due to cost may face higher risk of illness, including mental disorders, irrespective of diet. Geographical context is also critical, as plant-based diets are culturally dominant in some Asian countries, and mental health outcomes may differ substantially from those in European, African, or American populations. Furthermore, wide variation exists in many studies regarding the classification of plant-based diets, including vegetarian, vegan, and lacto-ovo-vegetarian diets, as well as other non-strictly vegetarian dietary patterns such as Mediterranean, pesco-vegetarian, and semi-vegetarian diets, which complicates valid conclusions within the examined relationship [186].

Recent studies and reviews reveal key insights regarding the relationship between plant-based diets and mental health. A retrospective cohort study using data from the Chinese Longitudinal Health and Longevity Survey examined 1666 adults aged over 65 years between 2008 and 2018 to investigate the association between plant-based dietary patterns and the long-term trajectory of depressive symptoms [208]. Three trajectories of depressive symptoms were identified. Participants with the highest adherence to plant-based diets were less likely to follow a moderate or highly progressive depressive trajectory compared to those with the lowest adherence. Conversely, higher adherence to an unhealthy plant-based diet was associated with increased odds of being on a moderate or highly progressive depressive trajectory. These findings suggest that adherence to healthy plant-based diets may protect against unfavorable depressive trajectories, whereas unhealthy plant-based dietary patterns may exacerbate long-term depressive symptoms. In parallel, a scoping review analyzing dietary intake and plant-based interventions in individuals with substance use disorders reported that plant-based dietary interventions in these populations were associated with improvements in overall diet quality, resilience, and self-esteem [209]. Another scoping review addressing the social consequences of veganism found that vegan diets can elicit both negative and positive social experiences, which may influence mental health [210]. Comparisons of mental health outcomes between vegans and omnivores yielded mixed results, with some studies reporting poorer mental health among vegans and others finding no differences. Finally, an umbrella review synthesizing evidence from nine systematic reviews assessed associations between plant- and meat-predominant dietary patterns and depression [211]. Among these reviews, five reported associations between dietary patterns and depression, with four suggesting that plant-predominant diets were linked to increased depressive symptoms, while five reviews found conflicting or null associations. Based on the aforementioned, overall current evidence on plant-based diets and mental health seems to be inconclusive, with methodological limitations undermining the reliability of existing conclusions and highlighting the need for further research in this area.

Clemente-Suárez et al. [212] conducted a systematic review examining the relationship between vegan and vegetarian diets and neurological health. Analyzing 112 studies published between 2010 and 2024, the authors concluded that plant-based diets are typically rich in phytonutrients and antioxidants, which are associated with lower levels of inflammatory markers such as CRP and IL-6. These findings suggest a potential role for these diets in reducing systemic inflammation and oxidative stress, both of which are implicated in neurodegenerative processes. However, deficiencies in critical nutrients, including vitamin B12, omega-3 fatty acids (particularly eicosapentaenoic acid and docosahexaenoic acid), and iron, have been consistently linked to an increased risk of cognitive decline, mood disturbances, and neurodegenerative disorders. Moreover, antinutritional factors such as phytates and oxalates may further impair nutrient absorption, highlighting the importance of careful dietary planning and, when necessary, supplementation. Emerging evidence also suggests that plant-based diets may influence mental health via the gut–brain axis. A systematic review conducted by Medawar et al. [213] reported an overall robust support for beneficial effects of a plant-based diet on metabolic measures in health and disease. However, the authors also reported that the evidence for cognitive and mental health effects of a plant-based diet is still inconclusive, highlighting the potential role of microbial intervention strategies for treating neuropsychiatric conditions. In this respect, nutritional psychiatry has gained increasing relevance in clinical practice, as numerous dietary components and nutraceuticals have been shown to influence central nervous system function through the gut–brain axis, with the combined supplementation of psychobiotics representing a synergistic approach to treating certain mental health conditions [214]. Psychobiotics are a novel class of psychotropic agents that include living microorganisms and bioactive substances capable of exerting beneficial effects in individuals with brain-related disorders, including psychological, neurodegenerative, and neurodevelopmental conditions [215]. These agents act on gut–brain signaling pathways and have demonstrated promise in the mitigation of prevalent adverse mental health states, such as stress, anxiety, and depression [216]. Psychobiotics can be delivered via supplements, functional foods, or targeted dietary strategies, and encompass probiotics, prebiotics, synbiotics, postbiotics, and certain plant-derived components [217]. Within this context, integrating plant-based diets into schools not only addresses environmental and physiological health challenges, but also underscores the pivotal influence of nutrition on mental health. Insights from nutritional psychiatry, including the potential of psychobiotics, reinforce the need to view school environments as instrumental platforms for fostering psychological well-being in future generations through the implementation of innovative nutritional strategies that extend beyond traditional dietary frameworks, potentially reducing reliance on pharmacological treatments, as their side effects may pose significant risks during early stages of development.

5. Determinants of Plant-Based Diet Implementation in Schools

Adopting plant-based diets within education systems involves multiple factors at the family, school, and community levels. Evidence indicates that peer and social influences play a crucial role in shaping children’s and adolescents’ eating behaviors, suggesting that peer networks may serve as important leverage points for promoting healthy dietary patterns, including plant-based options [218]. Similarly, attitudes toward food choices, such as concern for animal welfare or environmental impact, are influenced by underlying human values, which may affect receptivity to plant-based diets [219]. A narrative review conducted by Nekitsing et al. [220] highlighted that taste exposure, sensory learning, and nutrition education can be pivotal in promoting vegetable intake in preschool children. Taste exposure showed the strongest effects, while sensory learning had moderate success. In turn, nutrition education alone was less effective, underscoring the need to combine it with experiential strategies. In this respect, research indicates that emphasizing taste and attractive eating contexts tends to be more effective than abstract ethical or health messaging, particularly for omnivores [221]. Similarly, studies on nudging strategies and messaging interventions suggest that placement, social norms, and customized communications can modestly increase acceptance of plant-based foods [222,223]. In addition, sensory optimization of plant-based products may enhance their acceptability. For instance, plant-based foods designed to mimic the sensory properties of meat can compete with traditional meat products, even when participants are aware of the alternative protein source [224]. Culturally adapted plant-based diets have also been shown to be as acceptable as omnivorous diets in adult populations while maintaining dietary satisfaction, indicating potential feasibility for broader dietary interventions [225]. Nevertheless, it is also important to highlight that vegetarians and vegans frequently face negative attitudes and discrimination, which manifest as stereotypes, moral judgments, and social distancing, and are shaped by social norms, gender, age, and cultural factors, with ethical or environmental motivations and veganism eliciting the strongest reactions [226].

5.1. School-Related Barriers and Facilitators

Evidence from international studies highlights that schools are effective platforms for promoting plant-based and health-promoting diets, although their impact can be constrained by a range of individual, interpersonal, environmental, and systemic barriers. Moreover, diverse factors such as parental and teacher engagement, institutional support, and cultural norms strongly influence the success of interventions. Programs that integrate experiential learning, create supportive food environments, actively involve educators and families, and align school meals with broader sustainability objectives appear particularly promising for achieving durable dietary change.

A qualitative study from Australia, involving 19 parents and 17 teachers, underscored the strengths of schools in promoting healthy eating through food and nutrition education, role modeling, and supportive food environments. However, participants pointed to barriers such as limited educator knowledge, time constraints, and inconsistent food policies, emphasizing the need for institutional support and policy enforcement [227]. Comparable findings were noted in the United States, where a study of 261 children and 19 teachers across early childhood schools showed that embedding nutrition education into classroom activities enhanced children’s fruit and vegetable (FV) preferences. Teachers highlighted experiential strategies such as repeated exposure and tasting opportunities as key to strengthening the acceptance of children for healthy foods [228]. In addition, teacher perspectives in South Africa emphasized that schools offer opportunities to promote nutrition knowledge and skill development, but barriers such as lack of time, limited resources, unhealthy vendor food, and peer influences limited effective delivery [229]. Moreover, a mixed-method study conducted in Germany with 3015 adolescents found that efforts to transform school catering were hindered by insufficient public funding, conflicting stakeholder demands, limited educational opportunities, and parental or peer influences [230].

Parental and teacher support appears to constitute a critical facilitator for implementing plant-based initiatives in schools. In Portugal, a survey of 104 parents and 252 teachers found that teachers were slightly more supportive than parents of school policies promoting plant-based eating, with support linked to favorable social norms and lower attachment to meat [231]. Nevertheless, cultural perceptions of meat consumption can create socio-emotional barriers. In Portuguese schools, strategies to promote plant-based eating included leveraging ethical and environmental motivations, expanding plant-based availability, and engaging local communities [232]. Similar insights were reported in Southern Europe, with parental attitudes playing a decisive role. In France, nearly half of 1261 parents supported twice-weekly vegetarian meals, with motivations related to environmental, health, and animal welfare concerns [233]. However, sensory preferences and familiarity were identified as barriers reducing willingness to opt for vegetarian meals. Complementary evidence from Italy showed that dynamic social norm nudges encouraged the selection of environmentally friendly school meals, particularly among parents with lower education and strong child-related engagement [234].

Barriers can also be noted in early care and home settings. In the United States, a cross-sectional study with 163 early childhood education directors reported that food costs and children’s food preferences were the main barriers to implementing mandatory nutrition standards, although centers involved in federal programs, thanks to reimbursement structures, were able to comply better [235]. Another qualitative study conducted in the United States with 25 parents of children aged 6–12 identified limited time, food costs, junk food requests, picky eating, and early exposure to unhealthy foods as obstacles, with parents of overweight/obese children also reporting less spousal support [236]. A study in South Korea with 15 overweight/obese children and their parents complemented these findings by reporting barriers such as permissive grandparents, reliance on convenience foods, rapid eating at home, poor cafeteria environments, ineffective nutrition education, and inconsistent teacher management [237]. Furthermore, a survey with 106 teachers from the United States revealed that competing academic demands, insufficient time, weak curricula, and unsupportive environments limited nutrition education [238]. The study also reported that teachers recommended integrating nutrition into core subjects, aligning cafeteria offerings with lessons, and engaging parents to enhance impact.

Efforts to align school meals with sustainability goals provide additional insights into the topic. A controlled intervention across six Swedish schools tested a low-carbon lunch menu by substituting high-impact foods with climate-friendly alternatives [239]. Results showed that the intervention reduced greenhouse gas emissions without reducing pupil acceptance, with explanatory videos provided as part of the intervention. However, although pupil acceptance remained generally high, there was no significant effect on meal satisfaction, highlighting the limited immediate impact of menu changes. In addition, the OPTIMAT™ study, which implemented a four-week sustainable menu, demonstrated that while pupils and kitchen staff recognized the value of diet sustainability, barriers such as limited culinary skills, peer influence, and low familiarity with plant-based foods were present [240]. In this study, facilitators included gradual introduction of new dishes, careful attention to taste and presentation, and stronger leadership and stakeholder involvement.

A wide range of interventions specifically focused on the consumption of FV also point to both barriers and facilitators. In Australia, an intervention improved parental FV intake and reduced perceived barriers (e.g., dietary habits, high cost, limited appeal, lack of knowledge on preparation), showing the potential feasibility of peer-led approaches [241]. In Canada, a gardening and snack program with Indigenous children improved FV knowledge and preferences at school, but these changes did not extend to the home environment, with limited support and early exposure to unhealthy food acting as barriers, which highlights the importance of bridging school and family environments [242]. Qualitative evidence from the Netherlands showed that low intention among adolescents to eat more plant-based foods stemmed from limited knowledge and poor taste perceptions, although many felt capable of temporary adherence if given appropriate skills and awareness [243].

School gardening programs have been particularly prominent in the context of plant-based diet promotion. A study conducted in the United Kingdom indicated that teacher-led interventions were associated with higher fruit intake, while externally led programs improved vegetable recognition, suggesting that empowering teachers may produce more sustainable outcomes [244]. In Belgium, the “Taste Garden” program was well received by teachers and students, although its effects were limited to minor improvements in awareness and knowledge [245]. In addition, the “Eat Your Way to Better Health” program, conducted in United States, improved the self-efficacy of children and fostered FV intake [246]. An integrated program conducted in South Korea, combining gardening, nutrition education, and cooking, improved preferences, consumption, and reduced food neophobia [247]. Similarly, in the United States, a 12-week schoolyard garden program increased FV consumption and enhanced nutrient intake [248]. Moreover, combined classroom-garden interventions in Australia increased willingness to taste vegetables and improved preferences, although intake remained largely unchanged [249]. In turn, a study conducted in Nepal indicated that limited home access to FV and low parental involvement may hinder the impact of school garden, whereas integrating gardening with educational lessons and promotional activities could increase children’s knowledge, awareness, and preferences [250]. In the United States, school-based interventions adopting multicomponent approaches also showed promising effects on dietary knowledge and attitudes among children. For instance, students exposed to both gardening and classroom lessons demonstrated greater improvements in knowledge, preferences, and cafeteria choices than peers receiving classroom instruction alone [251], while combining teacher training and parental workshops further strengthened children’s attitudes toward FV. However, changing actual consumption remained challenging [252].

Longitudinal studies have highlighted durability and family engagement as key conditions for success. A panel study in the USA showed that school gardening improved vegetable recognition, preferences, and willingness to try, although it remains unclear whether these changes persist long term [253]. Further evidence from Nepal, through a one-year randomized trial conducted across 30 schools, demonstrated significant improvements in vegetable intakes among children, nutrition knowledge among caregivers, agricultural skills, and home gardening, underscoring the importance of interventions that connect schools and households [254].

Table 2. Barriers and facilitators for adopting plant-based diets in schools.

Reference	Intervention	Barriers	Facilitators	Limitations
André et al., 2024 [239]	Sweden. Quantitative, pre-post controlled intervention study. N = 653 children.	No significant effect of either menu change or added information on the acceptance of pupils, suggesting limited immediate influence on meal satisfaction and consumption.	Implementation of low-carbon recipes fostered positive engagement. Providing clear information on environmental impact and sustainability enhanced awareness and receptivity without negative effects on consumption.	Small sample. Schools already accustomed to vegetarian meals. Acceptance may vary with local norms.
Aydin et al., 2022 [227]	Australia. Qualitative, cross-sectional study. N = 19 parents and 17 teachers.	Limited knowledge from educators, time constraints, and inconsistent food policies that hindered plant-based diet promotion.	Increased knowledge and awareness of health and environmental benefits, positive social modeling from peers or family members, easy access to appealing and nutritious plant-based foods, and supportive policies or institutional norms.	Convenience sampling. Rural participants underrepresented. Potential self-selection bias. Exploratory qualitative design limits generalizability.
Caso et al., 2024 [234]	Italy. Quantitative, between-subject experimental study. N = 617 parents.	Some parents lacked awareness or engagement with sustainable school meals.	Dynamic social norm nudges successfully encouraged parents to choose more environmentally friendly meals, especially among those with lower education levels.	Single-task focus. No standardized taxonomy for social norms. Small, non-representative sample. Hypothetical choices may introduce bias. Cross-sectional design. Nudge effect may be exaggerated.
Dahmani et al., 2024 [233]	France. Quantitative, cross-sectional study. N = 909 parents (from 1261 children).	Sensory preferences and familiarity reduced willingness to support vegetarian meals.	Parental support increased when linked to higher education, flexitarian or vegetarian diets, and motivations related to health, environment, or animal welfare.	No quota-based recruitment. Low response rate. Participant imbalance. Possible parental bias. Children’s perspectives excluded.
Eustachio Colombo et al., 2021 [240]	Sweden. Qualitative, cross-sectional study. N = 29 children and 13 kitchen staff.	Habitual eating patterns of pupils, sensory factors, peer pressure, and general dislike of school meals limited acceptance. Lack of stakeholder involvement (from pupils to municipality decision makers) and insufficient staff training hindered implementation.	Facilitators included gradual introduction of plant-based meals, careful attention to seasoning, naming and aesthetics of dishes, leadership support, and training for kitchen staff. Education in sustainable diets and involvement of multiple stakeholders also promoted acceptance.	Only three schools in one municipality. Selected grades only. High non-participation. Local variation not captured.
Glasson et al., 2012 [241]	Australia. Quantitative, pre-post controlled intervention study. N = 292 parents.	Eating habits, perceived high cost, lack of interesting or tasty ways to serve fruit or vegetables, lack of knowledge on how to prepare vegetables.	Facilitators included peer-led education, follow-up newsletters, guidance on serving sizes and recommendations, strategies to overcome barriers, and enhanced self-efficacy for increasing family fruit and vegetable intake.	Short follow-up. Self-reported data. Seasonal effects. Partial use of peer educators. Generalizability and feasibility limited.
Graça et al., 2022 [232]	Portugal. Qualitative, cross-sectional study. N = 33 stakeholders.	Cultural attachment to meat and socio-emotional factors acted as barriers to plant-based meal adoption.	Ethical and environmental motivations, improved meal availability, and community engagement facilitated acceptance of sustainable diets.	Focus on Portuguese public schools. Private schools excluded. Small stakeholder samples. No longitudinal or experimental designs. Transferability limited.
Hanbazaza et al., 2015 [242]	Canada. Quantitative, longitudinal intervention study. N = 116 children.	Lack of family or household involvement likely limited behavior transfer from school to home.	Experiential learning and repeated exposure at school improved the knowledge and taste preferences in children toward fruits and vegetables.	Moderate dropout. Non-randomized design. No control group. Self-reported data. Long-term changes not consistent.
Havermans et al., 2021 [243]	The Netherlands. Qualitative, cross-sectional study. N = 11 adolescents.	Low interest in plant-based diets, insufficient knowledge of dietary components, limited awareness of associated health and environmental benefits, and inadequate cooking skills. Anticipated poor taste, unfamiliarity with plant-based foods, and lack of experience using meat and dairy alternatives further hindered acceptance.	Facilitators included temporary confidence in adopting a plant-based diet, increased familiarity with plant-based foods through repeated exposure, supportive environments at school, home, and via social media, and nutrition education that incorporated cooking skills.	Small non-representative sample. Limited triangulation and adherence. Possible misinterpretation of “plant-based diet”. No participant background. Limited generalizability.
Hennchen et al., 2024 [230]	Germany. Mixed-methods study. N = 3015 adolescents (quantitative).	Insufficient funding, conflicting stakeholder demands, and parental or peer influences.	Opportunities for student engagement and systemic support could facilitate healthier and more sustainable practices.	Restricted generalizability beyond Germany. Non-representative Berlin schools. COVID-19 may have affected participation.
Hutchinson et al., 2015 [244]	United Kingdom. Quantitative, longitudinal intervention study. N = 777 children.	Gardening alone was insufficient to change attitudes toward fruit and vegetable consumption. Lack of complementary nutrition or cooking education limited behavior change. Pupils with high baseline knowledge had little room for improvement. Limited comprehension among English-as-second-language students hindered engagement.	Teacher-led gardening improved the attitudes and willingness of children to try new fruits. Greater gardening intensity positively influenced fruit and vegetable intake. Combining hands-on gardening with classroom education and supportive home environments enhanced intervention impact.	No non-gardening control. High dropout and potential ceiling effects. Self-reported data. No direct measure of fruit and vegetable intake differences.
Huys et al., 2019 [245]	Belgium. Quantitative, pre-post controlled intervention study. N = 350 children.	Short intervention duration, limited time for activities, minimal parental or community involvement, and inconsistent implementation reduced effectiveness and hindered changes in vegetable consumption, knowledge, and awareness.	Positive reception by teachers and children, and higher-quality implementation enhanced knowledge and awareness.	No long-term follow-up. Urban setting only. Non-random assignment and unmatched groups. School dropout and delayed implementation. Self-reported data may introduce bias.
Kararo et al., 2016 [246]	The United States. Quantitative, pre-post intervention study. N = 222 children.	Short intervention duration, pre-existing food habits, limited parental involvement, and low household availability of healthy foods hindered the potential for sustained dietary behavior change.	Experiential learning through gardening enhanced engagement and self-efficacy for healthy food choices. Multisensory, curriculum-integrated activities supported knowledge acquisition. Community collaboration facilitated program implementation and potential scalability.	Convenience sample. No experimental design. Self-reported data. No triangulation. Missing demographic data limits assessment of program effects.
Kim et al., 2019 [237]	South Korea. Qualitative, cross-sectional study. N = 15 overweight/obese children and 15 parents.	At home, parental food preferences, sibling differences, permissive grandparents, convenience foods, and fast eating created barriers. At school, time pressures, poor cafeteria environments, ineffective nutrition education, inconsistent teacher management, and unsafe food environments hindered healthy eating.	Awareness of the home and school environment’s influence and coordinated efforts among children, parents, teachers, and community members facilitated healthier eating.	Small metropolitan sample limits generalizability beyond Korea. Key stakeholders excluded. No analysis of parent–child perspectives or school-level barriers.
Kim et al., 2020 [247]	South Korea. Quantitative, pre-post intervention study. N = 202 children.	Lack of parental involvement and uncertainty about long-term sustainability and generalizability limited the potential impact of the intervention.	Hands-on gardening and cooking experiences increased food familiarity and reduced food neophobia. Improvements in dietary self-efficacy, outcome expectancies, gardening knowledge, and nutrition knowledge positively influenced vegetable preferences and consumption. Sensory exposure reinforced willingness to try new foods.	Pre-post design, single school. No control group. Parents not involved. Long-term effects not assessed.
Kupolati et al., 2016 [229]	South Africa. Qualitative, cross-sectional study. N = 24 teachers.	Limited school time, scarce resources, unhealthy vendor foods, and peer influences obstructed nutrition education.	Teachers acting as role models and the presence of nutritious school meals and school gardens supported healthy eating promotion.	Potential response bias. Limited transferability to affluent schools. Missing insights from absent participants. Focus on experienced teachers only.
McAleese et al., 2007 [248]	The United States. Quantitative, pre-post controlled intervention study. N = 99 children.	External influences, including home environment, parental behaviors, and other classroom activities, hindered the effectiveness of the intervention.	Garden-based nutrition education increased fruit and vegetable servings. Experiential learning through gardening enhanced engagement and consumption behaviors.	Non-randomized trial. Short duration. Small sample. Self-reported data. External influences not accounted for. Long-term behavior change unknown.
Morgan et al., 2010 [249]	Australia. Quantitative, pre-post controlled intervention study. N = 127 children.	Limited program duration, short follow-up, and the complexity of dietary behavior change hindered improvements in fruit and vegetable intake.	Nutrition education improved willingness to taste vegetables, taste ratings, ability to identify vegetables, and preference for certain vegetables. Experiential learning via school garden enhanced engagement and knowledge.	Non-randomized, two schools only. Short-term 24-h recall. Limited generalizability. Clustering effects not accounted for.
Nepper & Chai 2016 [236]	The United States. Qualitative, cross-sectional study. N = 25 parents.	Parents’ time constraints, food costs, children’s preferences for junk food, picky eating, early exposure to unhealthy foods, and limited spousal support hindered adoption of healthier dietary habits	Parental strategies to manage time, cost, and picky eating, together with consistent support across child age groups, facilitated healthier dietary practices.	Single interview set. Age-related differences not fully captured. Exploration of barriers and strategies limited.
Parmer et al., 2009 [251]	The United States. Quantitative, pre-post controlled intervention study. N = 115 children.	Real-world school constraints and lack of long-term follow-up hindered the assessment of sustained dietary behavior change.	Integration of gardening with classroom instruction enhanced engagement, while combined nutrition education and gardening improved fruit and vegetable knowledge, taste ratings, and consumption.	Gender imbalance. Non-randomized design. Small sample. No follow-up.
Perera et al., 2015 [238]	The United States. Qualitative, cross-sectional study. N = 106 teachers.	Competing academic expectations, lack of time, insufficient curricula, and unsupportive school and home food environments hindered nutrition education.	Integration of nutrition education into core subjects, involvement of school cafeterias, and parent participation facilitated effective teaching.	Feasibility limited by time, resources, and need for external support. School-day constraints may limit implementation. Alternative strategies not addressed.
Prelip et al., 2012 [252]	The United States. Quantitative, quasi-experimental pre-post study. N = 399 children.	Limited effectiveness was hindered by low parent engagement, challenges implementing the program in large school districts, and absence of evaluation on curriculum delivery, resulting in no significant increase in fruit and vegetable consumption despite improved knowledge and attitudes.	Teacher training strengthened their ability to influence student attitudes toward fruits and vegetables. The multicomponent nature of the program promoted the engagement of students and reinforced nutrition education, supporting positive changes in knowledge, attitudes, and behaviors toward fruits and vegetables.	Convenience sample. Potential selection bias. Self-reported data. Low knowledge scale reliability. Small sample. Single urban district limits generalizability.
Ratcliffe et al., 2011 [253]	The United States. Quantitative, pre-post panel study. N = 236 children (questionnaire) and 161 children (taste test).	Improvements in vegetable consumption did not extend to the home, suggesting school-only programs may be insufficient. Gardens were often seen as supplementary rather than integral to the curriculum, which may have reduced teacher engagement.	Hands-on gardening enhanced recognition, attitudes, preferences, willingness to taste, and variety of vegetables consumed. Integration with academic curriculum supported learning and health promotion. Collaboration with teachers and health educators can reinforce nutrition education across the school day.	Pre-post design, no control group. Vegetable intake not measured. Long-term impact unknown. Limited generalizability.
Roque et al., 2023 [231]	Portugal. Quantitative, cross-sectional study. N = 252 teachers and 104 parents/caregivers.	Some parents were less supportive of plant-based school policies due to cultural attachment to meat.	Teachers’ favorable social norms, lower attachment to meat, and injunctive norms enhanced support for school policies promoting plant-based diets.	Small, convenience, non-representative sample. Self-selection bias. Ad hoc measures with uncertain validity. Children and adolescents excluded. No longitudinal or mixed-method design.
Schreinemachers et al., 2017 [250]	Nepal. Quantitative, cluster randomized controlled trial. N = 1275 (2014) and 785 (2015) children.	Limited access to fruits and vegetables at home and in the community, along with low parental involvement, may have hindered behavior change.	Integration of gardening with educational lessons and promotional activities increased children’s knowledge, awareness, and preferences.	Schools as intervention unit. Small sample of 30 schools. Baseline selection bias. Short duration and single 24-h recall. No mixed-methods evaluation.
Schreinemachers et al., 2020 [254]	Nepal. Quantitative, cluster randomized controlled trial. N = 779 children and their caregivers.	Standalone school gardens were insufficient to change eating behavior, as household food availability and caregiver practices strongly shape children’s diets.	Combined school and home garden approach improved caregiver nutrition knowledge, agricultural knowledge, liking for vegetables, and home garden productivity. Intervention highlighted the importance of targeting both schools and households.	Short-term (1-year) evaluation. Self-reported data. Only two treatment arms, limiting separation of school vs. home garden effects.
Stapp et al., 2024 [228]	The United States. Mixed-methods study. N = 261 children and 19 teachers.	Reliance on canned rather than fresh vegetables and variability in school meal offerings may have limited the effectiveness of the intervention.	Integrating nutrition education into classrooms increased children’s preference for fruits and vegetables through hands-on, experiential activities.	Cannot quantitatively measure impact on families’ fruit and vegetable intake.
Zoltz et al., 2018 [235]	The United States. Quantitative, cross-sectional study. N = 163 ECE center directors.	Food costs, children’s preferences, and additional financial and educational burdens limited adherence and program participation.	Intervention facilitated compliance through federal reimbursement and familiarity with regulations.	Cross-sectional design prevents causal inference. Self-reported data. No center-level compliance comparison. Only directors surveyed, not teachers.

ECE: Early Care and Education.

presents several barriers and facilitators identified for adopting plant-based diets in school settings.

Across the 28 reviewed studies conducted in 14 countries, the majority were from the United States (32.1%), followed by Australia (10.7%), Portugal, South Korea, Sweden, and Nepal (each 7.1%), and Germany, Italy, France, Belgium, the Netherlands, the United Kingdom, Canada, and South Africa (each 3.6%). Several consistent barriers to the adoption of plant-based or healthy school meals were identified: (i) children’s sensory preferences; (ii) habitual eating patterns; (iii) peer influences; (iv) time constraints and competing responsibilities affecting educators and parents; (v) limited knowledge or awareness of sustainable or plant-based meal options; (vi) resource constraints, including insufficient funding, infrastructure limitations, and high food costs; (vii) cultural attachment to meat; and (viii) low family involvement. These findings suggest that structural factors (e.g., time, resources, policies) and individual or socio-cultural factors (e.g., knowledge, preferences, cultural norms, family practices) may limit the implementation and acceptance of healthier or plant-based school meals. However, it can be inferred that cultural and socio-emotional determinants, as well as family involvement, despite being reported less frequently that other barriers, may exert a disproportionately strong influence on the adoption of plant-based diets, given the inherent difficulty of modifying deeply ingrained family values and established beliefs.

In turn, several facilitators consistently supported the adoption of plant-based or healthy school meals: (i) experiential learning and hands-on activities, including gardening, cooking, tasting, and multisensory curriculum integration; (ii) parental, family, and community support, often linked to higher education, ethical or environmental motivations, and to coordinated efforts among families, teachers, and community members; (iii) teacher role modeling and engagement, including leadership support and high-quality implementation; (iv) nutrition education and integration into core subjects or curricula; (v) social norms and ethical or environmental motivations; and (vi) systemic and institutional support, including policies and programmatic incentives. These results indicate that educational strategies, family and community engagement, social modeling, and institutional support converge to facilitate the adoption of healthier and more sustainable dietary practices in school settings. Experiential learning and active participation of multiple stakeholders appear particularly relevant, suggesting that hands-on engagement may reinforce knowledge, attitudes, and behaviors toward plant-based diets. Furthermore, another of the most salient facilitators appears to be associated with family influence, potentially reflecting that the transmission of values and modeling of dietary behaviors may play a central role in promoting the adoption of plant-based diets.

Finally, several methodological and contextual limitations were reported in the studies: (i) restricted generalizability and non-representative sampling; (ii) small sample sizes; (iii) limited stakeholder representation, including exclusion of children, teachers, or other relevant groups; (iv) use of cross-sectional, pre-post, or exploratory designs, which hinder causal inference or longitudinal assessment; (v) potential biases related to self-selection, self-report, or employment hierarchy; and (vi) contextual and logistical constraints, such as short intervention duration, reliance on specific school settings, and limited resources. These limitations underscore the need for larger, representative, and longitudinal or mixed-method studies that include multiple stakeholders to better assess interventions promoting healthier plant-based school meals and to understand the barriers and facilitators influencing their implementation.

5.2. Healthcare-Related Barriers and Facilitators

Healthcare professionals, through their guidance, recommendations, and modeling of plant-based dietary practices, can indirectly influence decision-making and the implementation of nutrition programs within schools and other educational settings. For instance, Canadian dietitians report generally positive attitudes toward plant-based diets and emphasize the value of nutrition education resources to support dietary counseling, suggesting that well-informed professionals can play a key role in shaping school-based initiatives [255]. In fact, educational institutions should remain up to date with medical and health recommendations regarding the healthiest dietary habits and patterns, including nutrition, which is a critical domain in this context. Therefore, understanding barriers and facilitators in healthcare contexts can help inform strategies to promote and implement plant-based initiatives in educational settings.

In general terms, plant-based diets are regarded positively within the healthcare context, although some concerns are also noted. Positive views include environmental sustainability [256] and positive outcomes in the management of specific conditions such as cardiovascular disease [257], chronic kidney disease [258,259], hypertension [260], obesity [261], and type 2 diabetes [262]. On the other hand, it has been reported that negative views may stem from the perceived risk of nutrient deficiencies among pregnant women and children [263,264], as well as the association of plant-based diets with eating disorders and related nutritional inadequacies in adolescents [265]. Despite these considerations, obstetricians and gynecologists generally perceive well-planned plant-based diets as safe and nutritionally adequate for pregnant and lactating patients [266,267]. Furthermore, emerging evidence indicates that well-planned vegetarian and vegan diets are increasingly recognized within healthcare contexts as potentially safe and nutritionally adequate for pediatric populations [268,269]. In a narrative review conducted by Sempa et al. [270] examining 27 studies, nine key domains were identified as determinants shaping the perspectives of health professionals regarding plant-based diets. These domains included educational resources, education and training, evidence-based guidelines, knowledge, lack of confidence in patient capabilities, lack of time, multidisciplinary collaboration, personal experience and interest, and safety and compliance challenges.

Table 3. Determinants shaping the perspectives of health professionals regarding plant-based diets.

Domains	Contributing Determinants
Educational resources	Accessible, evidence-based educational resources and practical tools, including apps, handouts, recipes, and visual materials, support effective counseling and implementation of plant-based diets.
Education and training	Limited education and professional training in plant-based nutrition reduce confidence in discussing and implementing it in practice, whereas additional education and training enhance the ability to provide effective nutritional counseling.
Evidence-based guidelines	Awareness of scientific evidence on plant-based nutrition influences confidence in discussing and recommending it, and access to clear, evidence-based guidelines enhances self-efficacy and supports clinical practice.
Knowledge	Sufficient knowledge of plant-based nutrition, including definitions, principles, health benefits, disease management, and supporting evidence, facilitates recommendation and implementation, whereas limited knowledge acts as a barrier.
Lack of confidence in patient capabilities	Perceived patient limitations, including low motivation, knowledge gaps, socioeconomic constraints, cultural habits, and reliance on convenience foods, can reduce confidence in successful adoption of plant-based diets, whereas simpler nutrient-focused advice may be seen as more feasible.
Lack of time	Limited clinician and patient time, including demands of staying current with literature and prioritizing convenience in food preparation, restricts discussion, counseling, and adoption of plant-based diets.
Multidisciplinary collaboration	Collaboration across health and scientific disciplines ensures consistent, evidence-based messaging and reduces confusion for patients regarding plant-based nutrition.
Personal experience and interest	Personal adherence to or experience with plant-based diets increases willingness to counsel and fosters positive attitudes, while lack of experience contributes to perceptions of diets as unrealistic, difficult, or unappealing, with interest influenced by health, ethical, environmental, and personal factors.
Safety and compliance challenges	Concerns about nutrient management, particularly potassium and blood sugar control in patients with comorbidities, can limit confidence in recommending plant-based diets.

provides a summary of these determinants, as reported by Sempa et al. [270].

The determinants shaping the perspectives of healthcare professionals on plant-based diets may have direct and indirect implications for their potential role in promoting school-based implementation. For instance, the availability of accessible educational resources and clear evidence-based guidelines reflects the need for standardized recommendations and strategies in school contexts, where teachers and food service staff could benefit from such tools when translating nutritional principles into practice. Similarly, the level of professional training and knowledge among healthcare providers parallels the requirement for nutrition proficiency within school staff, indicating that schools could benefit from similar capacity-building initiatives to enhance successful adoption. Barriers perceived by healthcare professionals, such as lack of time, patient motivation, or cultural food preferences, also reflect challenges faced in schools that can limit nutrition-based program effectiveness, such as lack of time for nutrition education, socioeconomic disparities, and ingrained dietary habits, all of which could be addressed through targeted strategies. Conversely, facilitators such as multidisciplinary collaboration and the positive influence of professionals with personal interest or experience in plant-based diets highlight potential synergies between healthcare and educational systems. In this sense, leveraging consistent messaging and role modeling could foster acceptance and compliance. Finally, concerns around safety and nutrient adequacy in clinical practice may impact school food provision, highlighting that schools might adopt approaches based on clinical evidence, since ensuring menus that are nutritionally adequate, sustainable, and ethically responsible is essential for the acceptability and long-term success of plant-based initiatives.

6. Toward Future-Oriented Dietary Guidelines

Global food systems face interconnected challenges related to human health, environmental sustainability, and social equity, collectively described as the Global Syndemic of obesity, undernutrition, and climate change [271]. Within this context, food-based dietary guidelines (FBDGs) have emerged as central instruments to address these crises, but assessments reveal substantial gaps in their integration of environmental and economic sustainability. Among 195 countries, only 37 (19%) explicitly address environmental sustainability, predominantly in Europe and Central Asia, while lower-income regions remain largely unrepresented [272]. Without explicit consideration of economic factors, including accessibility, affordability, and equitable wealth distribution, the practical implementation of sustainable dietary recommendations remains limited [271].

Transitioning to plant-based diets is increasingly recognized as a viable strategy to mitigate these challenges. Ethical, environmental, and health concerns associated with animal-source foods, such as high resource demand, greenhouse gas emissions, and diversion of cereals from human consumption, underscore the need to reduce red and processed meat intake, particularly in high-income populations [273,274]. Research indicates that partial replacement of animal protein with plant-based alternatives improves dietary quality, enhancing intake of fiber, magnesium, folate, and polyunsaturated fatty acids, reducing cholesterol, and increasing overall nutrient adequacy. However, excessive substitution may reduce protein, zinc, and vitamin B12 intake, highlighting the importance of well-planned, evidence-guided plant-based diets [275,276]. Epidemiologic and intervention evidence further corroborates replacing red and processed meats with plant proteins to reduce LDL cholesterol and lower cardiometabolic risk, aligning with current professional guidelines emphasizing the consumption of fruits, vegetables, whole grains, nuts, and legumes [277].

National policies and school-based interventions are critical levers to promote plant-forward dietary patterns. Evidence from Spain indicates that local food procurement initiatives in school canteens, although limited (approximately 2.2% of schools) and regionally heterogeneous, can support healthier menus and sustainable rural development when accompanied by governmental coordination [278,279]. Denmark exemplifies how consumer demand and international influences can drive sectoral transformation, with businesses adopting innovative strategies to expand plant-based food offerings [280]. Such experiences underscore the need for multi-stakeholder collaboration, including governments, civil society, and private enterprises, to foster sustainable dietary transitions.

Effective implementation of plant-based dietary strategies requires attention to cultural, ethical, and socioeconomic contexts. Nutrition-related interventions must engage stakeholders, balance potential benefits with unintended consequences, and incorporate monitoring and evaluation to ensure both health and ethical outcomes [281]. Integrating ecological economics principles, such as sustainable production, accessible nutritious diets, and green innovation, can enhance both the feasibility and effectiveness of FBDGs [271]. Collectively, these measures offer triple-duty benefits, simultaneously promoting human health, environmental sustainability, and social equity, highlighting the pivotal role of plant-based diets in advancing global food system resilience, and also underscoring schools as strategic platforms for fostering healthy and sustainable dietary habits among children and adolescents.

Indeed, across diverse global contexts, schools have progressively been used as platforms for fostering sustainable food practices and environmental literacy among young populations. In the United States, initiatives have ranged from food waste management, composting, and recycling programs [282,283] to curriculum-linked sustainability education, school gardens, and experiential learning through field trips [284,285,286,287,288,289,290]. Similar initiatives in Canada emphasized local and organic food procurement, vegetarian menu options, and integrated school gardens [291,292], while European and African schools implemented energy audits, recycling, agroforestry teaching, and regional food use [293,294,295,296,297]. In Asia, Japan has explored strategies to minimize lunch waste through pedagogical practices, portion adequacy, and composting [298], and in Finland, structured initiatives, such as the Helsinki Vegetarian Day, encouraged exposure to plant-based diets [299]. Brazil demonstrated engagement through school gardens, environmental education, and the promotion of local and organic foods, with some programs emphasizing practical sustainability skills such as recycling and use of returnable materials [300,301,302,303,304]. In Spain, local procurement and agroecological policies in school canteens highlighted how sustainability interventions can also contribute to GHG emissions reduction and rural development [278,305,306].

These diverse school-based practices illustrate how educational settings can integrate multiple dimensions of sustainability, from environmental and nutritional education to local sourcing and waste reduction, providing tangible models for promoting plant-forward diets. Interventions that combine experiential learning with structural changes, such as gardening programs, curricular adaptations, and procurement policies, can simultaneously enhance the knowledge of the students, influence dietary behaviors, and strengthen community engagement. Initiatives such as Meatless Monday campaigns [307] and Farm-to-School programs [298,308,309] demonstrate the feasibility of introducing plant-based options at scale while aligning with broader ecological and ethical goals. Collectively, these findings underscore the potential of schools as strategic platforms for integrating sustainable and health-promoting dietary habits, reinforcing the pivotal role of plant-based diets in shaping lifelong nutrition behaviors and contributing to environmental and social objectives.

7. Discussion

The present review was conducted to provide a comprehensive overview of the potential of plant-based dietary patterns, particularly vegetarian and vegan diets, to address the environmental, health, and social challenges associated with current food systems, considering the suitability of schools for shaping and promoting dietary habits. Based on the literature reviewed, several key points can be highlighted. First, animal-based food production drives major environmental pressures, including greenhouse gas emissions, biodiversity loss, and ecosystem degradation. Transitioning to plant-based diets, combined with sustainable agricultural practices such as optimized fertilizer use, crop diversification, and integrated farming systems, can reduce resource use and promote ecological sustainability. Thus, reducing animal protein consumption is completely essential for aligning food production with environmental preservation, thereby ensuring the long-term stability of planetary resources. Second, widespread animal exploitation and suffering raise profound ethical concerns and also desensitize individuals to violence, linking cruelty toward animals with increased risk of human-directed aggression and antisocial behavior. Schools and families provide critical settings to foster moral reasoning and empathy during childhood and adolescence. Integrating ethical education and promoting plant-based diets can counteract normalized cruelty and encourage the development of civically responsible and ethically aware behaviors that contribute to a more equitable social culture. Third, plant-based diets consistently provide metabolic, cardiovascular, and anti-inflammatory benefits across diverse populations, supporting healthy weight, glycemic regulation, and muscle function. Across pediatric contexts, interventions promoting plant-based eating have been shown to improve dietary quality, foster sustainable eating patterns, and support healthy growth and body composition, without compromising normal development when appropriately planned. Fourth, plant-based diets are associated with a particular GM composition, including increased Prevotella abundance and enhanced microbial diversity, which can influence metabolic, inflammatory, and cardiometabolic outcomes. Fiber-rich plant foods promote SCFA production, modulate microbial gene expression, and may mediate the effects of diet on glycemic regulation, satiety, and systemic homeostasis. Emerging evidence also suggests that GM shifts may play a role in whole-body regulatory mechanisms and potentially influence central nervous system function. Fifth, current evidence on plant-based diets and mental health is mixed and seems to be context-dependent. Well-planned plant-based diets, rich in phytonutrients, fiber, and antioxidants, may improve cognitive function and promote psychological well-being, potentially via the gut–brain axis and psychobiotic interventions. In educational settings, integrating plant-based nutrition programs offers a promising strategy to foster mental health, emphasizing the importance of careful dietary planning, supplementation when necessary, and early-life interventions. Sixth, the adoption of plant-based and healthier school meals is shaped by both structural and socio-cultural factors. Key barriers include children’s food preferences, habitual eating patterns, peer influence, time and resource constraints, limited knowledge, cultural attachment to meat, and low family involvement. Conversely, facilitators such as experiential learning, nutrition education, teacher and family engagement, social norms, ethical or environmental motivations, and institutional support promote acceptance and implementation. Seventh, healthcare professionals may play a potential role in promoting plant-based diets within educational settings. Their guidance, evidence-based recommendations, and role modeling can support the design, implementation, and acceptance of school-based nutrition programs. Educational resources and multidisciplinary collaboration can help ensure dietary interventions are safe, nutritionally adequate, and aligned with sustainability and ethical principles. Eighth, global food systems face challenges related to health, environmental sustainability, and social equity, which can be mitigated through plant-based dietary transitions. Well-planned plant-diets improve nutrient adequacy and address the environmental impacts of animal-based foods. Moreover, national policies, school-based initiatives, and multi-stakeholder collaboration facilitate their adoption. In particular, schools can serve as pivotal strategic platforms for fostering sustainable dietary habits, integrating experiential learning, local procurement, curriculum adaptations, and community engagement.

Current and projected environmental sustainability challenges are largely driven by existing food production systems and established societal dietary patterns. Although corporate interests exert considerable influence on public behavior through various channels, society retains a responsibility to engage in critical thinking and to mitigate such external pressures. Human behavior is often described as characterized by the capacity for ethical judgement and other morally relevant traits, distinguishing humans from non-human animals [310]. Paradoxically, humans frequently assert dominance over other species, despite the potential for animals to exhibit fewer negative behavioral traits. This perceived supremacy parallels historical patterns of domination, slaughter, and genocide within human populations, acts that have been widely condemned due to their intra-species nature. In turn, consciousness is frequently cited as a defining feature distinguishing humans from other species. However, evidence indicates that non-human animals may also possess varying levels of conscious awareness [311]. Moreover, minimal attention has been given to the shared capacity for suffering or comparable levels of awareness among neonates of different species, even in instances where animals are deliberately killed without legal or ethical protection, as illustrated by traditional culinary practices such as the consumption of suckling pig in certain cultural contexts. Although ingrained cultural practices may be resistant to change, current adult generations possess both the opportunity and arguably the ethical obligation to cultivate values in younger populations that emphasize animal welfare and promote sustainable practices. Such interventions may contribute to a more ethically coherent framework that aligns human activity with the welfare of other species and the long-term resilience of global ecosystems.

Violence toward animals is widely normalized, to the extent that harming non-threatening sentient beings is often trivialized across many cultures. Beyond familial influences, regional customs, and the corporate-driven mass production of animal-derived foods, media platforms may serve a significant role in shaping dietary behaviors and promoting ethically responsible and sustainable eating practices. Nevertheless, animated content depicting animal-directed aggression, as well as advertisements for animal-derived products explicitly designed to imprint on children’s memory, remain pervasive [312,313]. Interactive media, such as video games, constitute an additional influential factor, as active embodiment of characters can facilitate the internalization of observed behaviors. Evidence indicates that exposure to violent content through video games may normalize aggression, desensitize adolescents to violence, and increase the likelihood of real-world aggressive actions [314]. Numerous games even provide rewards for harming or killing animals, and in some cases humans, thereby reinforcing these behaviors. The differential legal and ethical consequences associated with harming humans versus non-human animals further highlight the ethical gap and the potential for societal reinforcement of violence toward animals. These considerations underscore the importance of early interventions. In this respect, educational and media strategies should focus on fostering ethical awareness, empathy, and understanding of the consequences of actions toward animals. Integrating moral and animal welfare education into school curricula, regulating exposure to violent media content, and promoting media literacy may mitigate the normalization of cruelty. Ultimately, cultivating a culture that acknowledges the intrinsic value of non-human life is critical not only for ethical considerations but also for the development of socially responsible and empathetic individuals capable of making informed dietary and lifestyle choices consistent with principles of sustainability and animal welfare.

Barriers and facilitators on diet implementation highlight that the successful integration of plant-based or healthier meals in school settings requires addressing practical and structural constraints, as well as fostering supportive social and cultural environments. Although certain barriers are deeply ingrained, the presence of diverse facilitators across multiple contexts suggests that coordinated interventions targeting education, family, and community engagement can yield meaningful improvements in dietary practices. Moreover, the variability observed across countries underscores the importance of customizing strategies to local cultural norms, policy environments, and resource availability. Future research and policy efforts should therefore adopt a holistic approach, considering the interplay of structural, social, and cultural factors to maximize the sustainability and impact of plant-based initiatives in educational settings. In addition to these considerations, there is a need to emphasize the potential benefits of integrating plant-based initiatives with broader educational goals, such as environmental literacy, health promotion, and social-emotional learning. By integrating nutrition and sustainability concepts into the curriculum and aligning them with experiential learning activities, schools can foster immediate dietary changes and also long-term shifts in attitudes and values toward food. Furthermore, attention to equity and inclusivity, ensuring that interventions are accessible and relevant across socio-economic, cultural, and geographic contexts, stands out as a crucial factor for both effectiveness and sustainability. The findings on this area also suggest that multi-level collaboration among policymakers, educators, parents, and communities may enhance the scalability of interventions, creating systemic support that reinforces individual and collective behavior change. However, in the school context, the success of dietary and health interventions largely depends on teachers and their capacity to transmit values and model behaviors. Although policies and regulations establish overarching frameworks, teachers remain a highly influential figure for students, sometimes even rivaling parental influence. Unfortunately, the models provided by educators are not always optimal. Across educational contexts, continuous evaluation of teachers regarding health, ethical principles, professional competencies, or mental well-being is often minimal or insufficient [315,316,317,318]. Ineffective or even harmful pedagogical practices, such as verbal reprimands or humiliation, are reported [319,320,321,322,323]. Furthermore, institutional corporatism among teachers, administrators, and inspectors may result in organized structures that protect colleagues, normalize unethical practices, and systematically obscure instances of negligence [324,325,326]. Such underlying structural and behavioral barriers can impede the successful implementation of school-based initiatives, highlighting the critical need for capacity building, accountability, and the promotion of positive role models within educational systems.

In 2019, the EAT-Lancet Commission on Healthy Diets from Sustainable Food Systems released a report advocating for diets with higher proportions of plant-based foods. The adoption of plant-based diets has increased globally, driven by growing concerns over environmental sustainability and the well-established health benefits associated with these dietary patterns. Several studies have found no significant differences in growth parameters between children following plant-based diets and those consuming omnivorous diets. Nevertheless, some evidence suggests a tendency toward lower growth indicators, including a risk of undernutrition, among children adhering to plant-based diets. Conversely, lower prevalence of overweight and obesity has consistently been observed in this population [327].

Although recent research has increasingly examined the health implications of plant-based diets in children, numerous questions remain unanswered, highlighting the need for further investigation. Key areas of uncertainty include (i) whether the health benefits and risks of plant-based diets vary across stages of development; (ii) the effects of supplementation with bone-supporting nutrients on skeletal health in vegan children; (iii) the potential consequences of consuming novel plant-based ultra-processed foods; and (iv) whether health outcomes observed in childhood translate into long-term effects in adulthood [328]. To address these gaps, several recommendations are proposed for future consideration: (i) the development of country-specific training programs for healthcare professionals on appropriate pediatric nutritional care for vegan and vegetarian children and their families; (ii) the establishment of national dietary and supplementation guidelines for vegan and vegetarian children, customized to developmental stages and regional dietary patterns; and (iii) the regulation of ultra-processed plant-based meat and dairy alternatives to ensure their safety and nutritional equivalence for pediatric consumption.

Dietary guidelines provide recommendations regarding meat consumption and its relationship with sustainability and environmental impact. A review of national food-based dietary guidelines indicates that most provide only generic information on sustainability and dietary patterns. A subset of these guidelines explicitly recommends reducing meat intake, while others suggest limiting dairy consumption [4]. However, these recommendations require refinement to clearly articulate the rationale for reducing consumption of animal-derived foods in the context of sustainability. The literature reveals a scarcity of specific, actionable guidance on sustainable diets within national guidelines [272], especially regarding the transition from ruminant-based foods to diets higher in plant-based foods [329]. Moreover, discrepancies exist between current research and published guidelines concerning which countries provide sustainability-related recommendations linked to animal- or plant-based diets [330]. Consequently, transitioning toward sustainable diets, including plant-based patterns, will necessitate systemic transformation and interdisciplinary collaboration among nutritionists, environmental scientists, economists, and public health professionals.

In essence, early educational settings represent an extraordinary opportunity to shape long-term health behaviors, as personal health trajectories during childhood and adolescence strongly influence outcomes in adulthood [331,332,333,334,335]. Schools provide an ideal platform to improve measurable health outcomes and academic achievement, as well as to foster critical thinking, motivation, and ethical awareness among students [335]. Despite generally favorable health indicators, suboptimal physical activity levels, inadequate FV intake, and engagement in risky behaviors such as alcohol consumption and smoking remain prevalent among school-aged populations [331]. In this respect, students adhering to vegetarian or vegan diets demonstrate higher health awareness, more consistent engagement in physical activity, and more favorable dietary patterns, including higher daily FV consumption, suggesting that diet type is closely linked with overall lifestyle behaviors [332,333]. By targeting both structural and behavioral factors, school-based interventions can serve to enhance individual health awareness, promote responsible lifestyle choices, and influence societal health trajectories through the development of future role models, including families, educators, and academic staff [331,334,335]. Thus, schools at a global level should consider the importance of implementing strategies that combine nutritional education and ethical considerations in order to support the wellbeing of young populations, foster social and moral development, and contribute to long-term public health and sustainable planetary practices.

Despite the comprehensive scope of this review, various potential limitations should be acknowledged. First, the heterogeneity of the included studies in terms of design, population characteristics, dietary assessment methods, and outcome measures. Second, the current evidence on plant-based diets in pediatric populations remains limited, and the inherent biases of existing studies restrict the ability to draw definitive conclusions regarding their effects. Third, regional and cultural differences in dietary patterns, food availability, and school-based nutrition programs were insufficiently represented. Fourth, this review does not follow a standardized systematic methodology. Fifth, given the narrative nature of this review, formal analysis of the methodological quality and risk of bias of the included studies were not performed. Finally, the narrative approach adopted in this review enhances readability and provides a clearer understanding of trends and the overall context, but it limits replicability, comparability across studies, and also relies on interpretive synthesis rather than quantitative analysis, so conclusions should be viewed as a thematic overview rather than precise, generalizable estimates.

8. Conclusions

Plant-based dietary patterns, particularly vegetarian and vegan diets, hold significant potential to address environmental, health, and social challenges associated with current food systems. Evidence indicates that such diets can reduce ecological pressures, support metabolic and cardiovascular health, promote healthy growth in pediatric populations, and modulate GM composition with systemic effects. Ethical considerations, including the prevention of animal suffering and the promotion of moral reasoning, further emphasize their societal relevance. As schools are uniquely positioned to influence long-term behaviors, they serve as crucial platforms for fostering these dietary shifts by integrating nutrition education, experiential learning, and community engagement. Effective implementation requires addressing structural and socio-cultural barriers, strengthening educator and healthcare professional involvement, and aligning policy frameworks with sustainability objectives. Coordinated, evidence-based, multi-level strategies that combine nutritional, ethical, and environmental perspectives can facilitate the adoption of plant-based diets, promoting both individual well-being and planetary stability, as well as fostering values that cultivate socially responsible future generations. Nevertheless, ongoing research is required to refine dietary recommendations, assess long-term health outcomes, and ensure nutritional adequacy across diverse pediatric populations. Thus, continued evaluation of school-based interventions and policy frameworks will be essential to optimize the integration of plant-based diets and to monitor their health, ethical, and environmental impacts.