Sustainability of Alternatives to Animal Protein Sources, a Comprehensive Review

Abstract

The manuscript was prepared to conduct a thorough analysis and deepen the understanding of sustainable food production and diets within the context of the challenges posed by intensive agricultural practices and their environmental impacts, as well as their effects on human health. The rapid growth of the human population necessitates an increase in food production to meet nutritional needs. However, increasing the production of animal-derived products, which are significant protein sources, is likely to worsen undesirable consequences, such as global climate change, greenhouse gas emissions, and a larger carbon footprint. Traditional farming techniques also contribute to environmental contamination due to the use of synthetic fertilizers and pesticides. Transitioning to a sustainable food production model that addresses food needs while protecting consumer health and the environment is crucial. The challenge for the food industry and research centers is to find and develop the production of alternative sources of protein. In addition to the technological problems that must be solved, there is consumer education focused on healthy eating and overcoming psychological barriers related to the consumption of new foods.

1. Introduction

The global human population is experiencing rapid growth, with projections indicating an increase to approximately 10 billion by 2050. Ensuring sufficient, secure, and sustainable food provision for this growing population poses a significant challenge, especially considering resource depletion, pandemics, and climate change. Over the past five decades, both meat production and consumption have increased, with expectations that this trend will continue to meet the rising demand for animal protein [1,2,3].

According to the World Economic Forum, global meat consumption is expected to double by 2050, driven by population growth and rising incomes, which will lead to changing dietary preferences. Despite the increasing recognition of plant-based diets and the popularity of vegetarianism, high levels of animal-origin food consumption persist in developed countries [4]. The rise in meat consumption will exacerbate adverse effects such as global climate change, greenhouse gas emissions (GHGs), and an increased carbon footprint. Additionally, traditional meat production contributes to water pollution due to the heavy use of fertilizers and pesticides [5,6].

The alarming forecast of greenhouse gas emissions growth is particularly concerning, as a significant portion of the 7.1 gigatons of carbon dioxide emissions, constituting approximately 14.5% of total emissions [7], originates from livestock supply chains [8]. Livestock farming for meat and dairy products accounts for 65% of total greenhouse gas emissions, with 45% of these emissions being methane [9].

The causes of food insecurity are multifaceted and include persistent inequalities, systemic weaknesses in food systems, and disruptive events such as the war in Ukraine, which has significantly impacted global food prices. Climate change poses a serious threat to food systems, as extreme weather events, including floods, droughts, and wildfires, increase the pressure on these systems and severely reduce crop yields [10].

Agriculture plays a significant role in surpassing three planetary boundaries: biodiversity loss and the biogeochemical cycles of nitrogen and phosphorus. Although current global food production yields a net surplus of over 80% of protein and approximately 8% calories, more than 800 million people experience food shortages, and over 2 billion suffer from malnutrition, which includes deficiencies in protein, vitamins, and minerals, as well as obesity. The environmental impact of food production is unsustainable [11].

Numerous countries have established ambitious targets to eradicate hunger by 2030 in alignment with the UN Sustainable Development Goal 2. However, the 2023 Global Report on Food Crises [12] reveals that in 2022, around 258 million people in 58 countries and territories experienced severe food insecurity. Given these climate challenges and existing inequalities, the development of sustainable and resilient food systems is more essential than ever [13]. An essential element of these systems is sustainable diets, defined as “those diets with low environmental impact that contribute to food and nutrition security and to the healthy life of present and future generations. A sustainable diet protects and respects biodiversity and ecosystems, is culturally acceptable, accessible, economically equitable and affordable; nutritionally adequate, safe and healthy, while optimizing natural and human resources” [14]. Defining diversified diets in this way shows the areas of impact in terms of: (1) well-being and health; (2) biodiversity, environment, and climate; (3) justice and fair trade; (4) organic, local, and seasonal food; (5) cultural skills and cultural heritage; and (6) food and nutrient requirements, food security, and availability [15]. The causes of food insecurity are multifaceted, involving persistent inequalities, systemic vulnerabilities within food systems, and disruptive events such as the war in Ukraine, which has significantly influenced global food prices. Climate change presents a significant threat to food systems, with extreme weather events, including floods, droughts, and wildfires, intensifying stress on these systems and severely reducing yields [10].

The aim of this study is to conduct an analysis and update the knowledge regarding sustainable food production and diets in the context of threats posed by intensive production systems, their environmental impact, and implications for human health. This research includes a review of consumer dietary behaviors from various countries concerning environmental threats and provides a synthetic overview of the advantages, development potential, and barriers to the production of alternative protein sources.

2. Methodology

This study involved an analysis of scientific publications focused on sustainable food production, sustainable dietary patterns, and alternative protein sources. The authors assessed the impact of traditional production methods on the natural environment and the influence of traditional dietary patterns on health. Against this backdrop, the study reviewed potential opportunities and challenges associated with the production of alternative protein sources as measures towards environmental protection, sustainable diets, and supporting sustainable development.

The multi-criteria evaluation method was used in the literature review. This study utilized the research question of what arguments support sustainable development in food production and the implementation of sustainable diets to meet food needs and improve health. The literature search within the analyzed scope was conducted between November 2023 and August 2024 using the Web of Science and Scopus databases. Scopus, one of the major commercial bibliographic databases, encompasses scientific literature from nearly every discipline, with a record count exceeding 94 million [16]. Web of Science provides access to a full spectrum of biomedical literature from agriculture to public health and zoology, drawing from multiple databases focused on multidisciplinary content in the natural sciences. Through specialized collections, the Web of Science enables searches for content relevant to scientists from various fields, including physics, engineering, and food science [17].

To obtain a broad spectrum of search results, combinations of keywords were applied: sustainable development, food production, sustainable diet, and alternative protein sources. For increased search precision, combinations of these words were employed. To depict consumer behaviors regarding the challenges of sustainable development, studies from various geographic regions and cultural backgrounds were selected. The search results were verified by researchers for relevance to the topic and purpose of the study. Subsequently, 284 articles that were most relevant to the topic and purpose of the study were subjected to further analysis.

Articles for review were included based on the following criteria: studies involving consumers engaging in activities related to sustainable development or sustainable diets and publications related to research on the development, implementation, and improvement of technologies for alternative protein sources production. In the case of review articles, synthetic coverage of the subject matter concerning current achievements in the development of alternative protein source production methods, comprehensive presentation of the effects of intensive food production, and prospects for transitioning towards sustainable food production and nutrition were considered.

3. Sustainable Development in Food Production

Food security and environmental sustainability are essential for the progress and development of economies and societies worldwide. Food security encompasses sufficient access for communities to safe, culturally acceptable, nutritionally appropriate, and wholesome food that maximizes social confidence and equity through a sustainable food system [18]. Food and agricultural security means access to safe and nutritious food and sustainable development. Sustainability is an integral component and prerequisite for food security, and nutrition is a prerequisite for availability, stability of supply, access, and utilization [16]. Today, food security and the impacts of industrial agriculture and humans on climate and ecosystems are becoming increasingly complex [17,19], and food insecurity is increasing. Existing agricultural systems are failing to address the global health and nutrition challenge, causing and exacerbating environmental damage and social injustice [20].

In the second half of the 20th century, global food production and distribution increased rapidly as a result of the intensification of agricultural practices. This was due to advances in crop research, expansion of agricultural land, mechanization, and the widespread use of synthetic fertilizers, pesticides, and genetically modified high-yielding crop varieties [21,22]. The significant increase in production, due to population growth and high global meat consumption, has raised concerns from the perspective of environmental protection, public health, ethics, and ideology. Scientists have identified several environmental problems, such as poor management of water resources and arable land, emissions of harmful gases, and loss of biodiversity [23].

Currently, there is substantial evidence suggesting that our existing global food systems and consumption patterns are unsustainable for both human health and the planet [24]. Food production contributes to approximately 21–37% of global greenhouse gas emissions [25], with agriculture responsible for about 70% of the world’s freshwater usage [26,27]. The environmental impact of diet is due to the amount of water and soil used, the amount of fertilizer and energy required for production, which are related to the use of potentially harmful substances (such as pesticides and medicines) and the reduction of biodiversity as an indicator of environmental damage, indicating the “environmental cost” of a food or food group [28]. The largest water footprint is from beef production in the pasture model, followed by plant-based scenarios, at around 57 and 42 m³, respectively [29]. Smaller water footprints are observed for animals kept in confinement, such as beef, pork, and chicken (~3.76–17.05 m³). This oscillation between animal proteins, even taking into account the on-farm and processing stages, is related to environmental factors (for example, ambient temperature and humidity), drinking water temperature, water quality, feed composition (nature of food and dry matter content), feed intake, animal size, body weight gain rate, and composition [30]. The reduction in environmental impact was progressively greater from a flexitarian diet to a vegan diet for all factors except the water footprint, which had the opposite trend. Reduction values ranged between 54–87%, 2–11%, 8–11%, and 41–46% for GHG emissions, freshwater use, cropland use, and fertilizer use (summing N footprint and P footprint), respectively [31,32]. When assessing energy requirements, it is estimated that about 89% of the total impact of plant products is attributed to the cultivation stage and only 10% to the grain processing stage. In comparison, the impact related to animal protein, more specifically beef, depends on the animal production method, and the environmental burdens associated with this stage range from 24% to 50%, while the slaughter and processing stage of meat can represent values greater than 74% of the total process impact [33]. The Mediterranean diet, as well as some diets related to national dietary guidelines in the study by Fresán and Sabaté (2019) contributed to significantly lower GHG emission reductions than vegetarian patterns (10% compared to a range of 22–87%) [34].

The use of antibiotics and other drugs in animal husbandry and agriculture also has negative implications. Public health concerns are particularly troubling due to the link between the consumption of red and processed meats and diseases such as colorectal cancer [35] and cardiovascular issues [36,37].

A large body of scientific evidence underscores the urgent need to change current dietary patterns in order to mitigate climate change. As a result, many initiatives and policies have been implemented to promote sustainable development. These efforts include international actions, such as the introduction of the UN Sustainable Development Goals [38] and national actions, such as the implementation of official dietary guidelines in several EU countries that explicitly recommend more sustainable diets [39].

The growing recognition of the necessity for a more sustainable food production system is evident. This system must satisfy food demands while protecting consumer health and the environment. Achieving this shift requires cooperation between the food industry, government regulatory agencies, and the scientific community to develop and implement strategies for preventing chemical contamination in food. Progress in food technology, risk assessment, and regulatory frameworks presents promising opportunities to ensure both food safety and sustainability [40].

Sustainable development has been integrated into international agreements, national regulations, and policies. Nearly all agri-food production necessitates some degree of land use. Decisions regarding land use impact where and how food systems operate, and subsequently, food systems affect land, water, and climate [41].

One of the sustainable agricultural practices is crop rotation. It is one of the basic agricultural methods, which has been replaced by intensive farming. It is crucial for optimizing the use of both artificial and natural resources. Crop rotation maximizes the efficiency of resource use and mitigates environmental complications that often result from continuous cropping [42,43]. Another practice is the use of polyculture, which is the simultaneous cultivation of many plant species in the same space, which increases land use efficiency and potentially farmers’ income [44]. Polyculture can be practiced in aquaculture, where it involves the joint cultivation of different species in the same aquatic environment, improving production profitability [42,45]. Another principle of sustainable agriculture is integrated pest management. It uses different pest control methods. These methods include biological control, habitat manipulation, and pest-resistant crop varieties. The aim of integrated pest management is to destroy pests while effectively minimizing harmful effects on the environment. Integrated plant protection reduces the dependence on chemical pesticides, contributing to maintaining ecological balance and preserving biodiversity [42]. An integral part of sustainable agriculture is also the use of renewable resources such as water and energy, which is crucial to minimizing the environmental footprint of agricultural activities.

Sustainable agriculture also uses technological achievements (in the framework of precision agriculture) and biotechnology. Precision agriculture uses advanced technologies to precisely adjust the use of inputs, such as fertilizers and pesticides, taking into account the variability of field conditions. The use of precision agriculture technologies takes place at important stages of the crop growth cycle (soil preparation, sowing, crop management, and harvesting), but also in animal breeding [46]. It has the potential to improve environmental practices by reducing unnecessary use of inputs and reducing pollution in sustainable agriculture. In addition, advances in digital technology, including 3D visualization [47,48] are crucial to engage younger generations and promote sustainable farming practices [49]. Two major technological trends can be distinguished in precision agriculture: (1) big data and advanced analytical capabilities, (2) aerial imagery, feeding and milking robots, and smart sensors [50].

The development of precision agriculture has been a major driver for the transformation of biotechnology, which offers a wide range of benefits, from increased crop resilience to reduced chemical inputs. It has thus had a significant impact on the environment and the economy [51,52].

The implementation of new production systems, increasing innovation in zootechnical practices are able to provide improved feed efficiency and cattle growth rates, resulting in a better impact on meat quality and carcass characteristics, in addition to reducing carbon footprint, ammonia emissions, and meat production costs [53]. Biotechnology centers are increasingly involved in maintaining the competitiveness of the poultry system in the face of emerging challenges. Moreover, the global experience of producers in the field of poultry breeding, as well as beef and pork production systems, shows that the formation of the quality of meat products begins with cultivation and is controlled at all stages of the food chain [54].

It is important to recognize that sustainable development has been a key focus of the United Nations (UN) for more than 30 years. These principles were initially presented in the 1987 Brundtland Report and were further detailed at the 1992 “Earth Summit” in Rio de Janeiro, where Agenda 21 was established [55]. A decade later, the 2002 “World Summit on Sustainable Development” in Johannesburg outlined strategies for more effective implementation of Agenda 21. Consequently, sustainable agriculture has progressively emerged as a major global objective [15]. Policies such as the United Nations Sustainable Development Goals [56] and the European Green Deal [57] are pivotal for global decision-making aimed at mitigating the anthropogenic climate crisis. Although these policies have different objectives, they share a commitment to promoting sustainable agri-food systems and environmental protection [58].

Additionally, several important initiatives related to sustainable development goals exist at both international and European levels. Internationally, the 2015 Paris Agreement on climate change, established during the climate conference in Paris, France, demonstrates strong links to the 2030 Agenda. On the European level, the European Green Deal, adopted by EU member states in 2019 [59], supports initiatives aimed at eradicating hunger, achieving food security, improving nutrition, and promoting sustainable agriculture, particularly within the framework of the “Farm to Fork” strategy [60].

Sustainable development in the agri-food industry pertains to meeting present and future food needs while preserving the integrity of natural resources and ecosystems [61]. This includes reducing the carbon footprint, safeguarding water and soil quality, and conserving biodiversity [62]. However, it should be viewed from a broader perspective that encompasses people, planet, and industry [63,64]. Sustainable food production, conceptualized as a guiding principle within the food cultivation system, intersects with various critical systems such as energy, trade, and healthcare, and has garnered escalating attention since the previous century [65]. At its core, it is grounded in principles that emphasize heightened awareness and empowerment, ensuring that short-term profitability is harmonized with long-term stability [66].

Increasing global incomes and evolving consumer preferences have heightened the demand for protein. Animal protein currently plays a crucial role in meeting this demand, and its production is projected to rise in the coming years [67,68]. However, constraints such as limited agricultural land and labor have hindered the expansion of animal husbandry, reaching saturation points in recent times. Food producers face obligations to uphold animal welfare and preserve land and biodiversity [69], posing challenges to efforts aimed at rapidly increasing meat production and supply in the short term [70].

4. Sustainable Diet and Consumption Patterns

The Lancet Commission in 2019 highlighted the pivotal role of food in sustainable development: “Food is the single strongest lever to optimize human health and environmental sustainability on Earth. However, food currently threatens both people and the planet” [15,24]. Sustainable food production encompasses diverse viewpoints and tackles concerns spanning the environment, economy, and society. Developing sustainable food production systems encounters obstacles such as environmental decline, competition for resources, rising food needs, and the incorporation of agriculture into the global economy [22]. Socially, sustainable food production aims to secure food and nutrition for future generations by integrating local resources and supply chains [71].

Transformative change across the entire food system, from farm to waste, is essential, yet agriculture alone is unlikely to achieve global climate goals without significant shifts in dietary patterns on the consumer side [72]. A globally advocated approach is the transition to a “sustainable diet,” which emphasizes high consumption of plant-based foods and whole proteins while reducing animal-based food intake. This shift promises additional benefits for both human health and environmental sustainability [24,73,74].

Adopting a less processed diet can benefit both health and environmental sustainability. Ultra-processed foods, which are unnecessary for a balanced diet, contribute to excessive consumption, one of the main drivers of the growing negative environmental impact [75,76].

The production of ultra-processed food is also a significant contributor to environmental pressure [75,76,77,78,79]. Each stage of the life cycle assessment of ultra-processed food production—monoculture farming, energy-intensive processing, long transportation chains, and excessive packaging—contributes to environmental pressure [76,80]. To align the food sector’s impact on climate with sustainable development goals and commitments to greenhouse gas emissions under the Paris Agreement, a shift in current consumption patterns is necessary [24,81,82]. Voluntary adjustments by consumers towards sustainable development will also be crucial in reducing the carbon footprint. Understanding changes in behaviors, habits, or strategies that consumers may adopt to reduce their greenhouse gas emissions is essential [81]. Adopting a less processed diet can benefit both health and environmental sustainability. Ultra-processed foods, unnecessary in a balanced diet, contribute to overconsumption, which is one of the main causes of the growing negative impact on the environment [75,76].

A sustainable diet protects and respects biodiversity and ecosystems and is culturally acceptable, accessible, economically fair, and affordable. This definition is widely accepted by the scientific community and typically appears in most works published on the subject of sustainable diet [15,83]. Sustainable consumption is often identified with ecological consumption. In line with this trend, the key to achieving the goal of sustainable development is changes in the area of consumption, not necessarily related to limiting consumption, but modifying it to minimize negative external effects. The concept of sustainable consumption is often considered in a narrow sense, focusing on ecological aspects while marginalizing the other two aspects of sustainable development to which it refers, namely economic and social [84].

Consumer attitudes towards sustainable diets are presented in

Table 1. Selected consumer attitudes towards sustainable development.

Consumer Behaviors towards Sustainable Development	Source
− Two-thirds of respondents consider the ideals of sustainable development to a “moderate” or “high” extent during food purchases. − 95% of survey participants have altered or are interested to alter their behavior in response to climate, environmental, or sustainable development concerns, with 40% showing a strong inclination toward behavior change. − 95% of respondents have changed or are willing to change their behavior due to climate, environmental, or sustainable development concerns, with 40% strongly inclined to change their behavior. − Respondents reported increased consumption of organic products, seasonal eating, and purchasing locally produced food.	[81]
− Around 70% of consumers are open to buying products with reduced or more environmentally friendly packaged materials, and 45% are open to increasing consumption of reginal food by 30%. − 40% of consumers intend to increase consumption of organic food by 30%.	[85]
− Consumers find the following adjustments easiest to incorporate into their daily lives regarding sustainable development: increasing consumption of fruits and vegetables, reducing the use of plastic bags, opting for seasonal products, purchasing local food, and minimizing food by-products.	[86]
− In particular, Italian shoppers who prioritize ecological consumption show greater concern for sustainable development in their dietary choices and tend to adopt more sustainable lifestyles overall.	[87]
− Increased consumption of organically grown food correlates with greater intake of plant-based foods, reduced meat consumption, and overall improved nutritional quality.	[88]
− More than half of Belgian consumers indicated that they purchase locally or organically produced food to safeguard the environment.	[89]
− The most commonly practiced principles are buying locally produced products, purchasing organic products, and choosing smaller packaging. When it comes to protein-rich and dairy products, the second most frequently observed practice is purchasing minimally processed food.	[90]
− Choosing fresh, local, and seasonal food reduces transportation and storage (e.g., in refrigerators), resulting in reduced calories consumption.	[91]
− Consumption of organic food; 54% of respondents in a study conducted in the UK try to avoid and minimize food waste.	[92]
− British respondents tend to favor making minor adjustments to their behavior rather than adopting more substantial lifestyle changes related to diet and transportation.	[93]
− More than 60% of British adults are prepared to decrease their meat consumption.	[94]
− Consumers interested in reducing consumption of meat were also more open to consuming cultured meat.	[95]

.

When it comes to dietary behaviors associated with meat consumption, studies by Palomo-Velez et al. [96], Einhorn [97], and Moreira et al. [98] have highlighted certain issues related to environmental degradation, health problems, and endangered animal welfare [96,97,98]. These issues have become a major research focus in food sciences. The literature indicates a growing concern for understanding the current state of research and future directions for adopting food alternatives to reduce meat consumption and address significant challenges in health and sustainable development [97,99]. On the other hand, considering the central role of meat in dietary routines and its various hedonistic, social, and cultural aspects, many consumers may be reluctant to eliminate this component from their meals [100].

Promoting a global reduction in meat consumption is both necessary and urgent, though challenging [101]. However, meat consumption is a voluntary behavior that can be modified. Some consumers, known as flexitarians, have transitioned to more sustainable dietary patterns by reducing the frequency of meat consumption rather than completely eliminating it [102]. While total elimination of meat may seem unrealistic, intermediate behaviors like flexitarianism have gained popularity [103]. According to Minotti et al. [104], adopting a balanced and healthy diet had a 47% lower carbon footprint and a 25% lower water footprint than an unhealthy diet, while at the same time affecting income and monthly food expenditure by an average of 13% less. Additionally, such a diet had a 21% lower impact on sanitary costs related to cardiovascular diseases [104]. Providing information, particularly about environmental benefits, is crucial for encouraging positive opinions. Lack of knowledge about new technologies can lead to distrust and concerns about potential long-term negative consequences [105,106]. Both GMOs and cultured meat are perceived as technological innovations that evoke feelings of distrust and unease [106]. Limiting false equivalences, such as associating cultured meat with GMOs, is important [105]. Economic accessibility and spending patterns also influence how sustainable practices are adopted and valued in each country, from more practical and affordable approaches to a preference for higher-end products. Economically developed countries may have a higher percentage of consumers willing to consume sustainable food products or services due to increased income. Spaniards attach greater importance to the use of reusable bags, Colombians prefer to buy local products. They negatively assess the impact of meat consumption on sustainability and express the belief that vegetarian diets are more sustainable, and affordable prices ensured by intensive food production. Turkish consumers perceived the importance of socio-economic, environmental sustainability [107].

New technologies and products, along with changes in dietary patterns, such as the growing vegan population, have the potential to reduce the environmental impact of food production [108,109]. This change has stimulated the evolution of agricultural policy and investments in research and development from various governmental and private sectors. Emerging technologies and products, coupled with shifts in dietary habits like the increasing vegan population, hold promise for diminishing the environmental footprint of food production [108,109]. This shift has spurred advancements in agricultural policy and investments in research and development across governmental and private sectors. Due to the diversity in geographical and cultural diets and agricultural methods, strategies for dietary modification will differ across national and local contexts [110]. Research indicates that substituting animal-derived products with plant-based alternatives in affluent and middle-income households can substantially lower environmental impact [111,112,113] and reduce the prevalence and mortality rates of noncommunicable diseases [32,114,115]. A very important direction will be the use of plant protein due to its lower ecological footprint and additionally the search for other alternative protein sources, such as insect-based diets, microalgae proteins, or fungi, which will enable safer and less polluting protein production [104]. Harmonizing the consumption of alternative plant proteins with the aim of reducing the environmental impact does not seem to be sufficient for those who usually eat animal protein. This is because although agriculture has promising carbon sequestration rates (~56% of CO₂), it is estimated that 9.9% of global greenhouse gas emissions are still related to agricultural activities. In addition, another aggravating factor is deforestation, with agriculture being responsible for over 75% of the devastation of the world’s territory [116].

Food waste is a substantial contributor to climate change, given that the environmental impact of producing each kilogram of unconsumed food equals that of a kilogram of consumed food. Similarly, food waste from plant-based diets generally has a smaller environmental footprint compared to waste from diets high in animal products [117]. In developed nations, household waste represents more than 40% of total food waste occurring at the retail or household level [118]. Per capita food waste at the household level remains a considerable concern across both high- and low-income countries. In 2019, households globally were responsible for 61% of total food waste, amounting to 931 million tons. Factors contributing to household food waste include excessive purchasing, over-preparation, large portion sizes, confusion over labels and expiration dates, storage challenges, and inadequate packaging, particularly for perishable items [119,120].

The environmental burden from food waste varies by country, depending on the quantity and type of waste and the stage at which it occurs. Research conducted across 15 countries found that food waste in affluent nations (such as the USA, Saudi Arabia, UAE, and Canada) had the most substantial environmental impact across nearly all categories assessed. In the USA, for instance, food waste contributed 172 million metric tons of CO₂ equivalent to climate change, depleted 22 million tons of fossil resources, and used 121 billion cubic meters of water resources. These environmental costs were markedly higher compared to those observed in lower-income countries such as South Africa, Mexico, Argentina, and Lebanon [121].

More effective public health initiatives are needed that promote healthy eating habits and overall lifestyles. To address this problem, school-based nutrition education programs are effective in promoting appropriate growth and improving children’s physical, social, and mental health while laying the foundation for healthy habits throughout adulthood. According to the WHO guide, educational programs should be child-centered, promoting active participation, with a planned curriculum that is appropriately designed for different stages of development [122]. Successful in-school initiatives, some of which include digital components, have been implemented in many countries [123,124,125,126,127]. Approaches to promote sustainable diets encompass adopting vegan or vegetarian lifestyles, minimizing food waste, choosing seasonal foods, opting for organic products, and selecting meats with reduced carbon footprints [128]. Changing dietary habits can be challenging, especially when influenced by factors such as tradition or the desire for self-improvement [129]. Sustainable eating behaviors often involve reducing meat consumption, particularly red meat, although this is less frequently mentioned than other behaviors like eating locally or seasonally and reducing food waste. Dietary changes are not explicitly associated with a specific diet type (vegetarian, vegan, or plant-based) [4]. A nationwide survey in the UK found that meat reduction was not listed as the most important action for a sustainable lifestyle [130]. Sensory appeal is a significant factor in food choices, proving to be a key determinant of regular consumption [131]. Positive and negative sensory experiences did not deter participants from trying various plant-based meat substitutes (PBM), such as minced meat, burgers, sausages, and nuggets [132]. Vitale et al. estimate that the mere reduction of red and processed meat consumption in the traditional Italian diet would reduce CO₂ production per capita by as much as 31% and contribute to greenhouse gas emission savings of over 50%. However, considering that a drastic reduction in red and processed meat consumption is unrealistic in the short term, it is worth emphasizing that even less radical changes would be beneficial for the time being and should therefore be supported [133].

Consumer knowledge about sustainability plays a crucial role in food choices. Studies show that consumers are more likely to engage in eco-conscious purchasing when they understand the significance of sustainability attributes at the product level or have high subjective environmental knowledge. Conversely, they are unlikely to engage in sustainable behaviors if they lack sufficient information about the issue, its potential consequences, and how their actions can contribute to its resolution [134]. Even motivated and concerned consumers need specific knowledge to choose sustainable alternatives from available options [135].

Common challenges for consumers include the complexity of preparing and locating meat-free meal choices. Other barriers include the habitual nature of meat consumption and its perceived necessity for a “proper meal,” as well as a lack of awareness about the negative health and environmental impacts of high meat consumption. Negative perceptions and concerns about the high sodium content and highly processed nature of substitute products also play a significant role [136,137,138].

5. Alternative Protein Sources

To adapt to the swift changes in the food supply chain and the consequent intense demand for high-protein products, the food production industry has been actively working to boost the production and processing of these products in recent years [139]. To address the ‘diet-environment-health’ trilemma [115] for both current and future generations, it is crucial to introduce sustainable and ethically justified alternatives to traditional meat production and consumption, such as plant-based protein sources [140] and insects [141].

Table 2. Opportunities and challenges related to alternative protein sources.

Alternative Protein Sources	Advantages and Development Potential	Reference	Barriers and Risks	Reference
Plant-based alternative foods (PBAF)	− Products frequently emulate the function of seafood and meat in the diet, providing consumers with real opportunities to transition to a diet with reduced meat and seafood content.	[142,143,144,145,146,147,148,149]	− The extensive processing involved in certain plant-based products has hindered their acceptance and sparked discussions regarding their long ingredient lists, nutrient composition, and potential health effects.	[94]
	− They are consumed as part of numerous dietary patterns aimed at promoting health and managing diseases, including the Mediterranean-style diet, the nutritional strategies to reduce hypertension diet, low glycemic index diets, and fiber-rich diets.	[150,151,152,153,154,155,156,157]	− Consumers perceive plant-based products as excessively processed and potentially harmful to health.	[158,159]
	− They allow for achieving satisfactory levels of protein in the diet, with the total replacement of animal-derived protein by other sources of protein such as amaranth, quinoa wheat, legumes, and soy-based products (tofu and tempeh). Therefore, protein-rich plants, such as legumes, can help reduce the demand for animal protein sources, which would bring enormous benefits to the environment.	[149,160,161]	− The significant processing that some plant-based food alternatives (PBAF) undergo may classify them as UPF and leads to increased salt and sugar intake, the consumption of which is associated with various adverse health outcomes.	[162,163,164]
	− Consumption of plant-based alternative foods has experienced a significant increase and shows signs of increasing. Higher consumption rates are observed among individuals who consume less meat, supporting the hypothesis that these products facilitate the transition to a diet with reduced animal-derived product intake.	[165]	− These products are seen as more modern, artificial, and expensive in comparison to legumes, which are viewed as healthier and more environmentally friendly.	[166]
	− There is a pressing need to expand the availability of plant-origin meat substitutes (PBMS) to meet consumer demand. Sales of plant-based products in Europe saw a notable increase of 49% from 2018 to 2020, with Spain alone experiencing a 32% rise in PBMŚ volume of sales from 2019 to 2020. This trend is evident globally, supported by studies conducted in various countries, including the UK, Brazil, Norway, USA, Australia, and Germany.	[27,167,168,169,170,171,172]
	− Factors contributing to the growing consumption of PBMS include health considerations, as well as concerns regarding animal welfare, greenhouse gas emissions, and the broader environmental impacts associated with meat production.	[173,174]
Microalgae	− Rapid growth in diverse habitats under conditions that support photosynthetic growth.	[175]	− Lack of awareness regarding the health benefits of their use, minimal incentives for producers.	[175]
	− Cultivation in closed systems or open ponds without the use of plant protection agents and pesticides.	[175]	− Difficulties regarding economic profitability.	[175]
	− High tolerance to environmental conditions—microalgae demonstrate greater productivity compared to conventional crops and can be cultivated in both different climates and extreme pH and salt concentrations.	[175]	− Enhanced biomass concentration, coupled with ample feedstock availability for extracting desired products, can be realized through high-density agricultural practices.	[176]
	− They utilize nutrients present in wastewater, thereby reducing the reliance on chemical inputs and freshwater.	[175]	− Unattractive taste, smell, and color, which completely alter the organoleptic properties of processed food.	[177]
	− Microalgae have a unique capacity to accumulate essential nutrients and bioactive compounds crucial for human health.	[178]	− Microalgae have intricate cell walls composed of layers including pectin, cellulose, alginate, fibrillar peptidoglycan, and various polysaccharides (such as cellulose and hemicellulose), which may adversely affect bioavailability.	[179]
	− Microalgae contain up to 50–70% protein in dry mass. Moreover, they are rich sources of vitamins, beta-carotene and polyunsaturated fats, vitamins, and beta-carotene.	[175]
Insects	− Edible insects, particularly those belonging to the order Orthoptera, are a rich source of protein, containing between 48% and 77% protein content. They also provide all essential amino acids necessary for maintaining a balanced and healthy diet.	[180,181,182]	− Insects can be either scavengers or parasites, primarily consuming grains, which may result in them carrying various pathogens.	[183]
	− Insects produce less pollution and residue compared to other vertebrates in traditional farming.	[181]	− The level and scope of contamination in insect-based food products are primarily determined by the insect species, the substrates or feed used in breeding colonies, the production methods, and the stage at which the insects are harvested.	[184]
	− Given insects’ minimal needs for water, land, and energy, their production is economically efficient. Since insects are poikilothermic, they can derive water from the moisture in their food. For instance, crickets require only 1.5 L of water to produce one kilogram of protein, whereas beef requires a substantial 3400 L for the same quantity of protein.	[181]	− Potential risks associated with consuming edible insects include consuming insects in inappropriate developmental stages, improper handling, and inadequate culinary processing.	[185]
	− By consuming organic waste and by-products, insects can process them into high-value food for humans or feed for animals, reducing land space for their production.	[181]	− For insect-derived foods, concerns arise regarding the consumption of vegetation/crops sprayed with pesticides, which may lead to pesticide bioaccumulation in their tissues.	[184]
	− They require six times less feed than cattle.	[186]	− Food neophobia, the fear or reluctance to try new or unfamiliar foods, plays a substantial role in influencing consumer acceptance of food products containing insects.	[187]
			− The taste and aroma of insects vary greatly, influenced by factors such as pheromones released, the habitat where insects reside, and the diet they ingest.	[188]
			− Allergies can result from the substantial chitin content present in insect exoskeletons. Responsible for allergies are certain types of enzymes in insects (arginine kinase).	[181,189]
			− Another concern is the potential for cross-reactivity between different species of insects.	[190]
			− Accumulation of heavy metals, particularly lead and cadmium, in insects varies depending on factors such as the insect’s feed, species, and growth stage.	[191]
Cultivated meat	− Cultured meat reserves can be manufactured with lower environmental impacts compared to traditional meat production methods.	[192]	− Large-scale processes for lab-grown meat are not currently operational. The availability and efficiency of selecting raw materials for culture media in necessary quantities are uncertain. Additionally, there is ambiguity surrounding the supply scale of growth factors, vitamins, minerals, and trace elements.	[173]
	− Production cultured meat can reduce water consumption, eutrophication potential, land use, and energy requirements.	[150]	− Despite expectations that consumers will support noninvasive meat production technologies that ensure improved health and meat quality, consumers approach such products with caution.	[69]
	− It possesses a desirable lipid profile (is free from cholesterol and contains low levels of saturated fatty acids).	[193]	− Moreover, socio-cultural differences play a critical role in influencing consumer responses to emerging food technologies.	[105]
	− Laboratory-grown meat is less susceptible to many microbiological and chemical hazards thanks to standardized production methods.	[193,194]	− High expectations for sensory attributes, along with the high cost, present significant barriers to the advancement of lab-grown meat production. The taste of traditional meat is challenging to replicate in lab-grown meat.	[105,193,195]
			− Cell-cultured hamburger meat would be priced at over $100 per kilogram for consumers. Most of production costs, about 85%, stem from expenses related to bioreactors, labor, and equipment. In addition to economic feasibility, certain technical challenges also hinder progress.	[196,197]
Mushrooms	− Mycoprotein includes all essential amino acids and boasts a net protein utilization similar to that of milk. Additionally, it supplies various minerals like iron, selenium, manganese, sodium, phosphorus, calcium and vitamin B2. Consuming mycoprotein reduces energy intake, which is especially advantageous for obese and overweight individuals, and is instrumental in promoting muscle protein synthesis in young individuals.	[198,199,200]	− Concerns regarding the consumption of mycoproteins include the production of microbiological toxins and the potential for allergies.	[201]
	− Life cycle assessments of mycoprotein production demonstrate reduced greenhouse gas emissions compared to both plant and animal proteins.	[202]	− Preliminary studies indicate that mycoprotein production requires substantial amounts of energy and high-quality raw materials (e.g., sugar), resulting in a significant impact on greenhouse gas emissions and energy consumption.	[203]
	− The global consumption of mycoprotein is on the rise due to its favorable nutritional profile.	[201]
	− For instance, including mycoprotein in the diet regulates blood insulin level and influences human digestive processes by delaying gastric emptying and intestinal motility.	[204]
	− Mycoprotein consumption improves blood cholesterol, promotes healthy muscle growth, and reduces calories intake in individuals who are lean, obese, and overweight.	[199,200,205,206,207]

outlines the opportunities and challenges associated with alternative protein sources.

From a sustainability perspective, the production of meat substitutes appears to be superior to conventional meat [150,151]. Meat substitutes necessitate less land area and generate significantly lower levels of greenhouse gases. This production approach is more suitable for adapting to climate changes impacting animal production, such as higher temperatures resulting in diminished feed conversion rates, decreased weight gain, and reduced reproductive success. The long-term advantage of cultured meat could arise from the availability of decarbonized energy sources [152,153].

Various categories of alternative proteins have been commercialized, including plant-based AP, algae, fungi, insects, etc. [154]. However, alternative proteins derived through cellular agriculture still encounter challenges related to scaling and achieving widespread commercialization [155,156].

Due to environmental and health concerns, there is a growing demand for meat analogs. The primary challenge lies in developing meat analogs that replicate the nutritional and sensory properties of traditional meat [157]. Meat analogs fall into several categories: cultured meat (produced from in vitro cell or tissue cultures), modified meat (involving genetically modified organisms (GMOs)), and meat analogs derived from plant sources such as soy protein or single-cell protein extracted from cultivated microbial biomass of bacteria, fungi, microalgae, and yeast [201,208,209,210,211,212]. Technical and scientific challenges hinder the widespread adoption and commercialization of cultured meat. Consumer acceptance and regulatory frameworks are crucial for future advancements. Multidisciplinary collaboration among scientists, social science researchers, economists, and marketing experts is essential to obtain the social and legal space for CM/CF/CS products’ acceptance [155].

The innovation process in the industry is tied to the availability of new products on the market. To create consumer demand, introducing new food products must combine technological innovations with a range of social and environmental changes, both large and small [213].

In Europe, the demand for plant-based protein will increase to EUR 7.16 billion by 2030, with a compound annual growth rate of 8.9% between 2023 and 2030. There is also a growing demand for plant-based milk substitutes and plant-based meat substitutes, which are likely to at least partially replace animal-based foods [214]. The search for new products, so-called plant-based meat, aims to make plant-based products more similar to a tasty experience similar to meat by matching product features such as taste, color, and texture. The result of such actions may be to attract and convince carnivorous consumers of the attractiveness of such products. However, the main challenge of the global market is to reach this group—omnivores—because they are a group more susceptible to dietary changes and can themselves be an example for skeptics [33].

Replacing animal-based protein may lead to a reduction in the amount of other important nutrients contained in animal-based foods. Pellinen et al. (2021) in a 12-week study of partial replacement of animal protein foods with plant protein foods found decreased levels of vitamin B₁₂ and iodine [215,216]. Beef, milk, eggs, and mackerel are rich sources of Fe, Ca, vitamin A, and vitamin B₁₂. A significant proportion of Fe in beef is in the heme form and has higher bioavailability than non-heme Fe found in plant foods [217], Ca in milk (and dairy products) becomes bioavailable in the gastrointestinal tract, while phytate in some plant foods can significantly limit the absorption of Ca, Fe, and Zn [214].

Plant-based products made from various row materials (e.g., soy, wheat, pea protein, mushrooms, beans, and lentils) have become increasingly popular. These products emulate the role of meat and seafood in the diet, offering consumers viable options to transition to a diet with lower meat and seafood consumption [218].

Plant-based alternative foods (PBAF) serve as a method to facilitate acceptance of changes in traditional meal structures and the development of new culinary skills necessary for transitioning away from animal-based products in the UK and other countries that have strong culinary traditions centered around meat and meat products [219]. PBAF, utilizing plant proteins such as soy, peas, nuts, oats, and mycoproteins, replicate the taste and texture of animal-based counterparts such as meat, milk, and dairy products. They are steadily gaining market share in the UK, with numerous major supermarkets expanding their selection of these products [27].

Transitioning to a high intake of plant-based foods and significantly reducing animal-based foods remains a key priority. Recommendations for a healthy and sustainable diet include significantly reducing meat consumption, particularly in high-income countries [74,220]. Reducing meat consumption positively impacts all areas of sustainability, including health, environment, biodiversity conservation, society, economy, and culture [221,222,223,224,225].

While vegetarians and vegans make up a small percentage of the population [226,227], and strict elimination of meat may not be feasible or necessary for most consumers, their dietary choices should be viewed as an initial step toward reducing meat consumption among those who prioritize sustainable eating [102]. Consumer segments, including omnivores (meat-eaters) and flexitarians (those who reduce meat consumption), make up a significantly larger proportion of the population in many developed countries. Understanding the motivations of omnivores and flexitarians is crucial for implementing meaningful, long-term changes towards reduced meat consumption in developed countries [228].

The meat substitute industry needs to convince consumers of the product’s value relative to its price and raise awareness of the benefits (taste, safety, health) and social benefits (environmental protection, food safety) it offers [70]. Cellular meat combines tissue engineering and cell culture to produce muscle tissue for food production, offering a more sustainable approach that respects animal welfare and reduces or eliminates antibiotics. Cell-based production also reduces the risk of chemical contamination, food-borne illnesses, and zoonotic diseases (E. coli, Campylobacter spp., and Salmonella spp.) compared to conventional meat [229].

Promoting in vitro meat could help reduce deforestation and support long-term environmental sustainability. Additionally, it can restore endangered animals to their ecosystems. The conventional global trade in rare and endangered animal meat is alarming and has depleted wild populations of many rare species in numerous countries [150].

Selected insect species are edible either in their entirety or as ingredients in processed food products. Entomophagy (insect consumption) has a long history that spans many cultures and is still practiced in selected regions, particularly in developing countries. Edible insects are commonly consumed by about one-third of the world’s population, especially in Africa, Asia, and South America [230]. Although insect-based food is not part of the Western diet, its farming and utilization as food and feed are expected to increase [231]. Insect-based food and feed are emerging parts of the agricultural sector, with insect protein production in Europe projected to reach up to 3 million tons by 2030 [232,233,234,235].

Insects can be used to prepare biscuits [236,237,238], snacks [239], enriched cornmeal [240], various breads [241,242,243], meat pies [244], and sausages [245]. Beetle powder [246] can be used to supplement wheat-based pasta. These food products are characterized by a higher protein content and better protein quality than their conventional counterparts [182,247,248,249,250,251]. Several studies have found the acceptability of cookies, honey paste, extruded rice products, crackers, and similar preparations with insects (whole or parts of them) directly detectable [239,252,253,254,255,256,257]. Although almost completely unexplored, food insects often exhibit a good taste and flavor similar to walnuts, hazelnuts, almonds, or shrimp and shellfish [258]. Given that insect consumption is not familiar to Western consumers [257,259,260], future research should focus on increasing the acceptability of edible insects. Another issue is the food safety of insects, whether collected in the wild or in cultivated fields. Direct or cross-reactivity (crustaceans) to insect allergens appears to be related to insect species [261,262], but processing of insect proteins can significantly reduce [263] the impact of this phenomenon.

Production of single-cell proteins offers several advantages over animal or plant proteins. It is independent of agriculture or climate, not affected by seasonal fluctuations, and does not necessitate arable land or freshwater resources. SCP facilities can be established virtually anywhere and have the potential for continuous operation [264,265]. Microorganisms can thrive on a diverse array of substrates, including low-cost waste materials (e.g., food waste, by-products of food processing, sewage, agricultural and forestry waste), CO₂, or methane [266,267,268]. The stability and efficiency of production processes are considered environmentally friendly, and microbial biomass represents a dependable alternative for ensuring future food security while mitigating the impact on global sustainable development [267,269].

SCPs are rich in proteins, often reaching up to 80% on a dry mass [266], and typically include lipids, carbohydrates, as well as various vitamins and minerals [265,270]. SCPs offer superior nutritional value compared to both animal and plant proteins [209,210].

SCPs are highly concentrated in proteins, up to 80% on a dry weight basis [266], and typically contain lipids, carbohydrates, and several vitamins and minerals [265,270]. SCPs possess superior nutritional value compared to animal or plant proteins [258,270]. Microorganisms that have been used to produce SCPs for human consumption, mainly including algae and fungi. Bacterial SCPs are currently predominantly used for feed applications but may potentially be utilized for food purposes in the future [266]. Autotrophic bacteria, which directly assimilate CO₂ as a carbon source, are receiving considerable attention in this regard [268,271,272].

The protein content in SCPs varies depending on the microbial species [267]. Growth conditions, including the substrate used, significantly impact microbial metabolism and the characteristics of SCP (protein content and amino acid profile) [273]. Generally, SCP production yields 50–80% protein content from bacteria and 20–60% from yeast [266,271].

Fungal proteins differ in nutritional profiles, lower production costs, and greater environmental benefits compared to plant and animal proteins. Filamentous fungi can be cultivated on inexpensive substrates, typically by-products and waste from food processing (e.g., sugarcane bagasse for Penicillium janthinellum cultivation), and forestry and agricultural activities [201,274,275]. Fermentation using edible filamentous fungi enhances the nutritional value of food. Mycoprotein production as an alternative to plant- or animal-based food production offers significant environmental benefits, including low environmental degradation, reduction/reuse of agri-food waste, decentralized production, and reduced greenhouse gas (GHG) emissions [198,201].

Cultural limitations in Western countries pose a challenge to the acceptance of filamentous fungi, some microalgae, and insects as part of the diet. Increasing knowledge about safety, nutrition, and health-promoting characteristics, along with informational campaigns, can help increase consumer acceptance [154].

Yeast protein biomass, with its high protein content and wide spectrum of amino acids, offers nutritional benefits as a dietary supplement for humans [276]. It is particularly recommended for vegan and vegetarian diets, individuals avoiding meat consumption, and adolescents during their developmental period [277]. Yeast protein can be certified by recognized halal and kosher organizations.

Agri-food by-product can serve as a nutrient source for mycoprotein production. In a specific study, date waste was utilized as a fermentation substrate for F. venenatum. The resulting mycoproteins did not induce allergic reactions, showed no expression of the fumonisin gene in the starter culture, and were free from mycotoxins such as zearalenone and deoxynivalenol in the fermentation medium. However, the fermentation process did reveal low levels of arsenic, lead, and cadmium [278]. Future research may explore the use of other waste materials for their potential in mycoprotein production.

However, considering that conventional food is cheaper than healthy alternatives and price is one of the most important factors in consumer decision-making, several strategies should be implemented simultaneously. This means reducing the cost of healthy food for consumers and providing dietary incentives, while introducing taxes to reduce the consumption of unhealthy and unsustainable food [279]. Young people show great interest in social media and mobile games, and their interaction is the basis for driving additional consumption motivation in young consumers [280]. The use of social media and gamification strategies can increase the effectiveness of their impact [281,282]. Due to the increasing global environmental problems such as global warming and climate change, environmental degradation, and pollution, sustainable consumption behavior has become one of the most important issues in the market as well as a research area in the last few decades. These problems can be alleviated by changing human behavior in a more environmentally sustainable way. Moreover, sustainable consumption behavior (buying and consuming products in an environmentally friendly way) is considered a prerequisite for promoting sustainable development. Changing unsustainable consumption habits is crucial to realizing the vision of sustainable development. Moreover, all EU Member States have committed to achieving sustainable consumption as part of promoting the Sustainable Development Goals [283,284].

6. Conclusions

Intensive food production significantly impacts environmental degradation, and the necessity to increase production to meet the growing population’s food demand will exacerbate these effects. Climate change and emerging extreme weather phenomena will complicate the stability of food production conditions, potentially intensifying food supply issues such as hunger or malnutrition in poorer regions of the globe. Traditional dietary patterns based on animal-derived raw materials, highly processed foods, and unbalanced high-energy diets with mineral and vitamin deficiencies contribute to the development of lifestyle diseases. Applying sustainable development principles is imperative to mitigate these negative impacts on the environment and human health. This includes reducing CO₂ emissions, protecting water and soil quality, and preserving biodiversity.

Promoting sustainable and ethically justified alternatives to traditional methods of meat production and consumption is of paramount importance. Achieving sustainable development goals requires building a value system and changing human awareness, which will affect both food production and consumption levels. Awareness of the importance of sustainable development attributes at the product level or subjective knowledge about the environment makes consumers more inclined to engage in environmentally conscious shopping. Promoting a transition to diets typically rich in plant-based foods and whole proteins while low in animal-based foods will benefit human health and environmental sustainability. The evolution of agricultural policy and investments in research and development of products should bring about new technologies and products, which, along with changes in dietary patterns such as the growing vegan population, can potentially help reduce the environmental impact of food production. In summary, sustainable methods of agricultural production or animal breeding using modern technologies should play a greater role in limiting the negative impact of agriculture on the environment in countries with low acceptance of alternative protein sources. On the other hand, in other countries where there is interest in alternative protein sources, an appropriate pricing strategy is necessary to increase the demand for healthier alternatives to animal products, creating incentives for interested, less affluent consumers. On the other hand, it should be expected that the direction of introducing additional fees for unhealthy products will be implemented in parallel. Additionally, technologies for alternative protein source production can significantly support sustainable food production systems. The gradual change in consumer awareness towards sustainable food will also change the perception of alternative protein sources, which are currently treated with reserve by most consumers. However, developing technologies for the production of alternative protein sources makes a lot of sense as a way to supplement the food deficit, e.g., in the case of natural or man-made disasters. These technologies also create the possibility of producing protein in isolation from the external environment, in a limited area, e.g., in areas with an extremely unfavorable climate for traditional food production, or as a way to reduce the costs of space missions related to transport costs and obtaining food in space.