Comparing meat alternatives for a sustainable food system

Abstract

This scoping review evaluates the potential of four alternative protein sources (plant-based meats, cultivated meat, insects, and single-cell proteins) to contribute to a sustainable food system. Using a holistic framework, each option is assessed across four dimensions: environmental impact, production scalability, consumer acceptability, and animal welfare. Plant-based meats rank highest, with established infrastructure, growing consumer acceptance, and substantial environmental benefits. Single-cell proteins show promise despite scalability uncertainties, while cultivated meat faces significant technical and economic challenges. Insect-based proteins encounter barriers across all dimensions, including limited environmental advantages and widespread consumer rejection. This multidimensional comparative analysis supports prioritizing plant-based meats in policy and investment strategies while highlighting critical research needs for emerging alternatives, demonstrating the value of systematic head-to-head comparisons in guiding resource allocation for sustainable food system transitions.

Introduction

Our global food system stands at a decisive crossroads. The environmental burden of conventional meat production presents an urgent challenge that demands immediate action. Livestock and associated feed crops occupy a staggering 77% of agricultural land worldwide while contributing merely 18% of calories and 37% of protein to human diets¹. Food production generates 35% of global greenhouse gas emissions, with animal-based foods responsible for 57% of this figure². The negative externalities of our current food systems reached an estimated US$14.0 trillion in 2018, with potential savings of up to US$7.3 trillion possible through a shift away from animal-sourced foods, driven by health and environmental benefits³. Research demonstrates that dietary shifts away from animal products, particularly in high-income nations, could provide substantial climate benefits through both reduced agricultural emissions and increased carbon sequestration on spared land⁴. Meanwhile, meat consumption is expected to keep rising globally until at least 2050⁵.

Despite these compelling reasons for dietary change, vegetarianism remains marginal in high-income and upper-middle-income countries⁶. Even the growing identification with flexitarianism in many Western countries has not translated into reduced meat consumption at national levels. Political leaders hesitate to implement regulatory measures due to limited public acceptance⁷, though international organizations increasingly recognize the need for coordinated action on alternative protein development⁸. Consequently, a proposed strategy to drive a dietary transition towards more sustainable protein sources involves offering consumers appealing alternative proteins closely mimicking the organoleptic qualities of conventional meat, yet with significantly reduced negative externalities^9,10.

However, after years of rapid growth in the alternative proteins sector, recent market contractions and facility closures reveal the critical importance of identifying which alternatives merit continued investment and policy support. Despite growing academic interest in alternative proteins, existing studies often fail to address a key question for policymakers and investors: which alternatives offer the greatest potential for transformative change? A fragmented understanding risks supporting solutions that, despite environmental advantages over conventional meat, may face serious limitations in scalability or consumer acceptance, thereby inadvertently impeding more promising alternatives, a costly mistake as the window for meaningful climate action narrows.

Recent studies have compared individual alternative proteins to conventional meat in terms of environmental impact^11,12 or consumer acceptance¹³. Yet direct comparisons between different alternatives remain scarce, and existing studies typically examine only one dimension. Scientists have only begun addressing this gap through more comprehensive frameworks. For instance, Sandhu et al.¹⁴ evaluated 13 protein production systems across 25 indicators spanning natural, human, social, produced capital, and governance dimensions. While their comprehensive sustainability assessment—examining indicators such as land degradation, livestock biodiversity, and farm worker health—provides valuable benchmarking of diverse production systems (from pastoralist to industrial livestock), it encompasses limited coverage of novel alternatives and does not prioritize factors determining market displacement potential. This methodological distinction between this review and Sandhu et al.¹⁴ reflects fundamentally different research objectives: assessing the multi-dimensional sustainability of production systems versus evaluating whether meat substitutes represent both sustainable alternatives and commercially.

To address this critical knowledge gap, this scoping review provides the first comprehensive comparison of four major alternative protein categories (plant-based meats (PBMs), cultivated meat, insects, and single-cell proteins (SCPs), evaluating each across environmental impact, production scalability, consumer acceptability, and animal welfare implications. Unlike previous reviews that focus on single dimensions or compare alternatives only to conventional meat, this analysis directly compares alternatives against each other to identify which options offer the greatest potential for sustainable protein transition. The novelty of this approach lies not only in the direct comparison between alternatives but also in revealing major trade-offs and synergies that single-dimension analyses miss. For instance, some production methods may simultaneously improve environmental performance and reduce costs, while others present trade-offs between scalability and sustainability.

Comparative analyses between alternative proteins are essential for informing effective policy and investment decisions, as every dollar invested in scaling a suboptimal alternative represents an opportunity cost: land not freed for restoration, emissions not avoided, or animal suffering not prevented. By ranking alternatives based on multidimensional performance and identifying synergies and conflicts between options, this scoping review helps evidence-based prioritization of research funding, policy support, and investment strategies that could help determine whether some alternative proteins might fulfill their transformative promise or risk becoming another well-intentioned failure in addressing our food system crisis.

Results

Conceptual framework and definitions

The selection of the four dimensions assessed in this article—environmental impact, production scalability, consumer acceptability, and animal welfare—emerges from both theoretical considerations and practical realities of food system transitions. Environmental impact represents the primary driver behind alternative protein development, as reducing the ecological footprint of food systems and especially protein production is essential for planetary boundaries and reaching climate targets¹⁵. Production scalability determines whether alternatives can achieve the scale necessary to meaningfully displace conventional meat, as niche products cannot drive systemic change regardless of their other attributes^16–18. Consumer acceptability ultimately governs market success, as products rejected by consumers cannot fulfill their intended role regardless of environmental benefits¹⁹. Animal welfare has become increasingly central to food system debates, driven by growing consumer concern about farm animal treatment and philosophical developments challenging the moral justification for animal exploitation^20,21. In addition, research demonstrates that ethical concerns about animals constitute a primary motivation for many consumers seeking alternatives²². The inclusion of this dimension recognizes that for many stakeholders, the ethical treatment of animals represents an increasingly important consideration independent of environmental or economic factors, as well as the increasing desire for a more ethically driven food system.

While nutritional adequacy and food safety represent important considerations, these dimensions were excluded due to fundamental data limitations. Nutritional profiles are well-documented for PBMs and partially available for insects, but remain extremely limited for some SCPs and almost non-existent for cultivated meat, where assessments rely primarily on theoretical projections. Similarly, safety data for novel technologies lack the empirical foundation needed for systematic comparison. Including these dimensions with current evidence would risk premature conclusions that could mislead policy decisions. These areas warrant dedicated research as the sector matures and comparable empirical data become available.

This multidimensional framework recognizes that successful protein transitions require solutions that perform adequately across multiple criteria, as good performance in one dimension cannot compensate for fundamental failures in others. Each dimension deserves a detailed explanation, given the methodological complexities involved in cross-alternative comparisons.

Environmental impact, the most extensively studied dimension in the scientific literature, encompasses the ecological footprint of producing alternative proteins from resource extraction through product delivery. This study synthesizes life cycle assessment (LCA) studies examining greenhouse gas emissions, land use and water consumption, while also trying to qualitatively assess biodiversity impacts.

Comparing environmental impacts across alternative proteins nonetheless presents significant methodological challenges that warrant careful consideration²³. LCAs, while providing valuable insights, often employ varying system boundaries, functional units, and methodological assumptions that can significantly influence their results. For instance, some studies measure impacts per kilogram of product, while others use protein content or nutritional value as functional units, making direct comparisons challenging. Furthermore, data quality and availability vary considerably across alternatives, with well-established products like PBMs benefiting from more robust empirical data, while emerging technologies like cultivated meat rely heavily on theoretical modeling and pilot-scale data.

The reliability of environmental metrics also differs across impact categories. While greenhouse gas emissions are generally well-documented and standardized, other metrics, such as biodiversity impact or water consumption, often lack standardized measurement approaches and empirical results. Additionally, most available LCAs focus on individual products rather than system-wide impacts, potentially overlooking important interactions and feedback loops within food systems.

Geographic and temporal variations add another layer of complexity. Environmental impacts can vary significantly based on location-specific factors such as energy grid composition, climate conditions, and agricultural practices. This variability is especially relevant for alternatives like insects, CMs, and SCPs, whose environmental performance is highly dependent on local conditions and input sources^24–26.

Finally, rapid technological developments in the alternative protein sector mean that older environmental assessments may not accurately reflect current production methods.

These methodological limitations and data gaps should be considered when interpreting the environmental comparisons presented in this review. Consequently, this paper focuses on relative performance patterns rather than absolute values, acknowledging that data quality varies considerably.

Production scalability assesses each alternative’s potential to achieve meaningful market penetration and replace conventional meat at scale. This dimension integrates economic viability (current production costs and price premiums), technical readiness (manufacturing process maturity and remaining challenges), infrastructure requirements (capital intensity and equipment needs), and input constraints (availability and price stability of key ingredients). Scalability analysis draws from techno-economic assessments where available, despite significant uncertainties, particularly for novel technologies²⁷.

It should be highlighted that the reliability of scalability assessments varies significantly across alternatives and metrics. Production cost estimates for emerging technologies rely heavily on projected learning curves and economies of scale that may not materialize as anticipated. Techno-economic analyses (TEAs) are to be understood as conditional estimates—not predictions—and many of them assume optimal operational conditions, continuous production, and mature supply chains that do not yet exist. For cultivated meat, particularly, cost projections span several orders of magnitude depending on assumptions about cell growth rates, medium recycling efficiency, and bioreactor design, none of which have been validated at a commercial scale.

These limitations underscore that scalability assessments presented in this review should be interpreted as indicative rather than definitive, particularly for technologies still in early development stages. Finally, it should be noted that comparisons with conventional meat prices are inherently skewed, as traditional meat production benefits from substantial subsidies^28,29 and fails to internalize significant negative externalities³.

Consumer acceptability integrates quantitative survey data (percentage willing to try/buy) with qualitative synthesis of barriers and facilitators. This study examines the likelihood of widespread adoption beyond early adopters, synthesizing evidence on sensory acceptance, cultural and psychological barriers, demographic patterns of acceptance, and market penetration data. This dimension proves particularly challenging to assess as most studies measure hypothetical willingness-to-try rather than actual consumption behavior, and acceptability evolves significantly with familiarity and repeated exposure^13,30.

Unfortunately, the scarcity of studies incorporating sensory evaluation through tasting, coupled with the limited understanding or unavailability of certain alternative proteins, limits the conclusions that can be drawn from the existing body of research, especially as many studies underline the importance of familiarity and a first tasting experience for the acceptance of novel food products^19,31. In the same vein, van der Weele and de Bakker³² synthesized empirical studies to show that acceptance patterns follow similar trajectories across different alternative proteins, with initial skepticism gradually giving way to acceptance as products become normalized. This might suggest that current acceptance metrics based on single-time evaluations might underestimate the long-term potential of these products.

Over the past decade, there has been notable progress in the field of animal cognition and behavior. It is now widely accepted within the scientific community that vertebrates are sentient and therefore capable of suffering^33,34. Current industrial animal agriculture involves at least 80 billion terrestrial animals killed yearly for food, to which billions of marine animals must be added³⁵. Alternative proteins could significantly reduce meat consumption, and therefore prevent the exploitation and suffering of billions of animals.

The animal welfare dimension evaluates the ethical dimensions of production systems, recognizing that many consumers choose alternatives for ethical rather than environmental reasons, and acknowledging current debates in moral philosophy about the moral status of animals and our obligations toward them^20,21. This dimension considers evidence for sentience and capacity for suffering, the number of individual animals affected likely for the production of each alternative, severity of impacts during rearing and slaughter where applicable, and indirect effects on wild animals through habitat modification.

Welfare assessments face inherent methodological challenges. Comparing suffering across species requires interspecies welfare comparisons that lack established scientific frameworks despite recent progress and propositions³⁶. Moreover, most welfare assessments focus on direct impacts while indirect effects through land use changes, pesticide applications, or ecosystem disruptions remain poorly quantified. These limitations mean welfare comparisons should be interpreted as very exploratory and indicative of major differences rather than precise measurements.

Applying this analytical framework requires a clear delineation of what constitutes an “alternative protein” and which categories merit comparison. For this review, alternative proteins encompass food products specifically engineered or positioned to replace conventional animal-derived meat in human diets. This definition requires three key criteria: (1) the product must be explicitly marketed or designed as a meat substitute rather than simply as a protein source, (2) it must attempt to replicate the sensory attributes (taste, texture, appearance) and the functional role of meat in meals, and (3) it must provide substantial protein content comparable to conventional meat products. This definition deliberately excludes traditional protein sources that have existed for centuries, such as unprocessed legumes, nuts, tofu, or tempeh, etc., which, while protein-rich, do not attempt to mimic meat’s sensory properties. The focus on “alternative” rather than “novel” proteins acknowledges that some technologies like mycoprotein and PBMs have existed for decades.

PBMs represent products manufactured from plant-derived ingredients that undergo extensive processing to replicate the sensory and functional properties of conventional meat. These products differ fundamentally from traditional plant proteins through their intentional meat mimicry, employing techniques such as extrusion, high-moisture processing, and protein structuring to create fibrous textures resembling muscle tissue. Modern PBMs typically combine protein isolates or concentrates (primarily from soy, pea, or wheat), lipids (often coconut or sunflower oil), binding agents (methylcellulose or starches), and flavor compounds designed to replicate meat’s taste profile. The category spans from products mimicking specific meat formats (burgers, sausages, nuggets) to those replicating whole-muscle structures³⁷.

SCPs encompass edible microorganisms, including algae, yeasts, fungi, and bacteria, cultivated as alternative protein sources. These proteins are typically obtained through fermentation, with some of them being processed to resemble meat. Although mycoproteins are not technically SCPs, and certain microbes and microalgae grow in structures beyond isolated cells, this article refers to these types of proteins produced via fermentation as SCPs³⁸. This review places particular focus on mycoproteins and the “power-to-food” (PtF) approach. Mycoproteins, also termed mycelium-based proteins, are generated by cultivating fungi in controlled aerobic fermentation systems where they receive essential nutrients such as nitrogen, carbon (primarily glucose), vitamins, and minerals³⁹. The PtF approach transforms atmospheric carbon dioxide into edible proteins through a combination of water electrolysis and microbial fermentation processes⁴⁰.

Cultivated meat (CM) is meat produced by cultivating animal cells⁴¹. Production usually begins with the acquisition and banking of stem cells or other relevant tissue material from an animal⁴². These cells are then placed in a controlled environment, such as a bioreactor, and provided with an oxygen-rich cell culture medium, composed of basic nutrients such as amino acids, glucose, vitamins, inorganic salts, and supplemented with proteins and other growth factors⁴³. An edible scaffold is sometimes used for the cells to multiply around, so that it forms a structured piece of tissue. Changes in the composition of the medium, sometimes in tandem with signals from the scaffold, trigger the differentiation of immature cells into the muscle, fat and connective tissue cells that make up the meat. The cells are then harvested and processed into meat-like products.

Entomophagy has garnered increasing interest in high-income countries, particularly following the influential 2013 FAO report⁴⁴. While Western insect companies currently focus predominantly on animal feed and pet food applications, they are simultaneously developing products for environmentally conscious consumers. These insect-based products appear in various forms, from whole insects to processed insect flour that serves as an ingredient in numerous food items, including meat alternatives such as steaks⁴⁵.

Environmental impacts

A recent literature review estimates that PBMs demonstrate approximately 50% lower environmental impact than conventional meat¹². Nonetheless, Santo et al.¹¹ indicate that processed PBM substitutes generate 1.6–7 times greater environmental impact than less processed plant protein sources such as tofu, pulses, and peas. Springmann⁴⁶ likewise documents this environmental differential between processed and unprocessed alternatives. Figure 1 illustrates GHG emissions estimated across selected LCAs examining PBMs. Consistently, all PBMs produce fewer GHG emissions than their animal counterparts, particularly beef^46,47. Multiple studies calculate that beef alternatives emit up to ten times less GHG emissions^48–51. For chicken and pork substitutes, research findings vary. Some studies reveal only marginal advantages for PBMs⁵², while others identify substantial differences^48,50 with plant-based alternatives demonstrating at least half the environmental impact.

Fig. 1. Summary of GHG emissions from a selection of LCAs of plant-based meat substitutes.

Data compiled from: Sun & Ruiz-Carrascal¹⁸⁷, Desiderio et al.¹⁸⁸, Heller and Selim⁵¹, Detzel et al.¹⁸⁹, Van Mierlo et al.⁵², Saerens et al.⁵⁰, Saget et al.¹⁹⁰, Saget et al.⁶¹, Smetana et al.⁴⁹, Santo et al.¹¹, Mertens et al.¹⁹¹, Fresán et al.¹⁹², Khan et al.¹⁹³, Mejia et al.¹⁹⁴, Keoleian and Heller¹⁹⁵, Goldstein et al.¹⁹⁶, Seves et al.⁴⁸, Van Mierlo et al.³¹, Dettling et al.¹⁹⁷, Mejia et al.¹⁹⁸, and Smetana et al.¹⁹⁹.

Land use requirements for PBMs generally fall substantially below their meat counterparts. The disparity appears most pronounced for beef, which necessitates up to 30 times more land than plant-based alternatives⁵³. Pork and chicken production requires between two and four times the land area compared to their plant-based substitutes^48,50,52. This reduced land footprint constitutes a significant environmental advantage as extensive meat production diminishes opportunities for land-based GHG offsets critical for climate stabilization⁵³. The substantial land allocation for animal agriculture creates areas where conservation efforts could simultaneously address climate change and biodiversity loss, with mapping studies identifying priority regions where carbon storage and biodiversity conservation goals overlap^54,55. Indeed, the substantial land allocation for animal agriculture incurs a “carbon opportunity cost⁵⁶” since this land could otherwise support vegetation-rich ecosystem restoration, offering considerable benefits for carbon sequestration and biodiversity enhancement⁵⁷. Hayek et al.⁵⁸ quantified this opportunity, calculating that transitioning global food systems toward plant-based diets by 2050 could facilitate sequestration of 332–547 GtCO₂, equivalent to 99–163% of the CO₂ emissions budget compatible with a 66% probability of limiting warming to 1.5 °C.

Moreover, a lower pressure on land would decrease the need for deforestation and hence lower biodiversity loss⁵⁷. Additionally, van Mierlo⁵⁹ and Fresán et al.⁶⁰ observed that on average plant-based alternatives required less water than meat. Saget et al.⁶¹ reported that PBMs were associated with 92–95% less marine eutrophication per unit of nutrient density compared to beef burgers. Some studies⁵⁰ suggested that, compared to beef burgers, plant-based burgers were associated with 67–97% less freshwater eutrophication and 83–92% less marine ecotoxicity.

In conclusion, PBMs demonstrate substantial environmental advantages across numerous criteria compared to conventional meat. These benefits appear most pronounced when contrasted with beef production and remain significant, though somewhat reduced, when compared to pork and chicken production.

Regarding SCPs, LCAs on SCPs are very rare, even for products already available on the market. Fernandez-López et al.²⁶ compared various SCP production systems and found that greenhouse gas emissions can vary dramatically, ranging from 0.61 kg CO₂-eq/kg protein for yeast SCP production from crude pea starch to 23 kg CO₂-eq/kg protein for mycoprotein produced from rice straw, illustrating the critical importance of substrate choice and production technology. Moreover, their results suggest that electricity consumption during fermentation consistently represents the main environmental hotspot across different SCP production systems, significantly affecting climate change, acidification, and eutrophication indicators. Their review also highlights the substrate type as having a great influence on the overall environmental profile, with non-feedstock SCP systems showing more favorable land use metrics compared to those using agricultural residues

Most LCAs to date find that mycoproteins have an equivalent³⁹ or lower^49,62 climate impact than chicken meat, and are in the same order of magnitude as plant-based substitutes or higher⁴⁹. Mycoproteins stand out for their very low land use⁶³ compared to both chicken and plant substitutes. However, energy consumption is consistently reported to be high⁶⁴, meaning the composition of the electricity mix can significantly impact emissions. Mycoproteins are also estimated to have less impact on biodiversity-related indicators than chicken. The environmental footprint of mycoproteins could be further reduced in several ways. Upcraft et al.⁶⁴ suggest using sugars derived from agricultural lignocellulosic residues, with promising results despite increased production costs. Additionally, agro-industrial residues with sufficiently beneficial nutritional profiles could supply mycoprotein production while decreasing environmental impact⁶³.

Few studies have been conducted on PtF approaches, and none are based on data from existing products. Nevertheless, three main conclusions emerge: PtF systems require significantly less land, emit fewer greenhouse gases, but are considerably energy-intensive^24,40,65,66. The energy source is crucial: Järviö et al.²⁴ observed an eightfold reduction in GHG emissions when using hydropower instead of the average Finnish energy mix. Sillman et al.⁴⁰ modeled different technological setups and found that in the best-case scenario, PtF can emit as little as 0.81 kg CO₂-eq/kg of protein, demonstrating significant potential despite the need for additional data. Additionally, research by Fasihi et al.⁶⁷ suggests that PtF approaches using renewable electricity could achieve significantly lower environmental impacts compared to conventional agriculture, requiring approximately 10–50 times less land area and 50–100 times less water than soybean production, while potentially offering comparable or lower greenhouse gas emissions.

Forward-looking modeling studies further support the environmental potential of SCPs at scale. Humpenöder et al.⁶⁸ projected that substituting just 20% of global ruminant meat consumption with microbial protein by 2050 could offset future increases in pasture area and reduce deforestation-related CO₂ emissions by approximately half, while simultaneously lowering methane emissions. These projections illustrate the significant environmental benefits that could be achieved through the scaled deployment of fermentation-based proteins or other alternative proteins with low land requirements.

In comparison to PBMs, SCPs can offer superior land efficiency but higher energy requirements, with PtF approaches demonstrating the most extreme trade-off: minimal land and water use (10–100× less than conventional crops) with very low potential emissions (0.81 kg CO₂-eq/kg protein), but relies heavily on low-carbon electricity.

Turning to CM, eight peer-reviewed LCAs on CM have been published to date, with findings summarized in Fig. 2. Without operational commercial-scale facilities, these studies rely on early-stage projections, exhibiting high uncertainties depending on assumptions about culture medium sourcing and cell-cultivation efficiency.

Fig. 2. Comparison of the results of selected life cycle analyses about cultivated meat published in peer-reviewed journals.

Data from: Sinke et al.²⁵, Kim et al.²⁰⁰, Tuomisto et al.⁷⁰, Smetana et al.¹⁹⁹, Mattick et al.²⁰¹, Tuomisto et al.²⁰², and Tuomisto et al.²⁰³.

LCAs identify low land use as CM’s main advantage over conventional meat. Sinke et al.²⁵ estimated CM requires 64% less land than chicken and up to 90% less than beef, a key consideration as spared land could support biodiversity or carbon sequestration. However, Kossmann et al.⁶⁹ found no significant land use improvement over industrial pork when using plant-derived macronutrients exclusively. CM would also generate less air pollution, soil acidification, and marine eutrophication^25,70. With regard to the carbon opportunity cost associated with livestock farming, CM has also been mentioned as having strong potential⁷¹.

Regarding GHG emissions, CM outperforms beef²⁵ but shows mixed results against chicken and pork. Sinke et al.²⁵ found CM superior to chicken and pork under “sustainable” energy scenarios but inferior under “conventional energy” scenarios due to CM’s massive energy consumption, nearly 5.5× conventional meat on average, which typically represents the largest contributor to overall impact. Although studies on the environmental impact of seafood are scarce, they suggest that cultivated seafood offers some advantages over conventional seafood⁷².

Not all environmental aspects favor CM. For example, Sinke et al.²⁵ observed blue water use for CM 1.3, 1.9, and 1.2 times larger than for chicken, pork, and beef from dairy cattle, respectively. Their results also suggested CM might perform worse regarding terrestrial ecotoxicity, human non-carcinogenic toxicity, and freshwater eutrophication. Likewise, Tuomisto et al.⁷⁰ observed that even in their most favorable scenario, CM still had a greater environmental impact than poultry regarding energy consumption, ozone formation, production of particulate matter, and freshwater eutrophication.

Overall, the environmental impacts of CM production are driven by the amount and sourcing of energy used at the facility, the sourcing and production of inputs in the medium, the design of the bioreactors for large-scale production, the efficiency of the medium, and the type of cells used. Other parameters, such as the reuse of the medium, also play a role, but likely to a lesser extent. Beyond process optimization, environmental benefits could arise from utilizing agricultural and food processing side-streams as nutrient sources⁷⁰, valorizing cultivation byproducts such as lactic acid, and eliminating fetal bovine serum (FBS) from culture media⁷³.

Note that most of the current projections focus on medium to long-term scenarios with optimized production processes. In contrast, a recent LCA by Risner et al.⁷⁴ examines short-term production scenarios for CM. Based on three metabolic scenarios (glucose consumption rate, amino acid requirements, and enhanced metabolism), their findings reveal global warming potentials ranging from 12.31 to 1508.3 kg CO₂-eq/kg depending on assumptions about media composition and purification requirements. However, Swartz et al.⁷⁵ critique these estimates as significantly overstated, questioning particularly the 20× purification factor applied to all media inputs and the assumed media requirements that exceed demonstrated conversion rates. This debate underscores the substantial uncertainty in assessing this emerging technology.

For insects, only 5% of the industrial insect industry’s funding was directed to insects as human food⁷⁶. Moreover, nearly 90% of insect-based food items consist of products like pasta, protein bars, whole insects, or biscuits, which do not substitute meat but rather products already having minimal environmental footprints^76,77. Meat substitutes accounted for only 7% of the new product launches in the insect-based food sector during the period from January 2014 to May 2023 for the four EU-authorized insect species⁴⁵. It is therefore important to highlight that evaluating insects as meat replacements diverges from the industry’s current trajectory, despite widespread assumptions about insect consumption as a sustainable protein alternative to meat. While this section draws predominantly from studies examining insects as animal feed due to limited research on insects as food, these assessments can reasonably serve as optimistic estimates for human food applications, as insect production for human consumption would likely require additional processing beyond feed applications, e.g., to enhance palatability and texture, presumably increasing environmental burdens.

Insect consumption is frequently promoted as environmentally advantageous compared to meat. Early research by Oonincx and De Boer⁷⁸, demonstrated promising environmental performance for mealworm farming (2.7 kg CO₂-eq/kg fresh weight), with subsequent studies reporting emissions between 4.2 and 20.4 kg CO₂-eq/kg per kilogram of edible product^79–82. These figures, while systematically lower than for beef, may not be any more favorable than those for chicken and pigs. While insect production appears to be less land-intensive, water consumption remains understudied, with one of the few investigations on this topic reporting higher water use for insects compared to conventional livestock⁸³.

Note that recent research incorporating more realistic production parameters offers a less optimistic perspective than previous results. For instance, a UK government-commissioned LCA comparing black soldier fly larvae with conventional protein sources for animal feed revealed considerably higher climate impacts (12.9–30.1 kg CO₂-eq/kg protein) across various substrate scenarios, including food waste, chicken manure, and commercial feed. This study identified energy requirements for maintaining optimal rearing conditions as the primary environmental burden in both feed and food production systems⁸⁴. Importantly, geographical context matters: many existing assessments were conducted in regions with socio-economic and climatic profiles different from Western countries, and additional heating requirements in temperate zones may further increase environmental footprints⁸⁵. Conversely, poor environmental performance obtained from studies on Western farms cannot necessarily be generalized to insect farming in tropical climates.

Feed composition emerges as another decisive factor in environmental performance^82,86,87, with comprehensive assessments showing that the environmental benefits of insect farming are highly dependent on whether side-streams can actually substitute for conventional feed ingredients. However, the widely advocated use of low-value organic waste encounters significant practical barriers^88,89. Questions persist about whether unprocessed organic waste alone can sustain mealworms and crickets populations at commercially viable growth rates⁹⁰. Research has identified an important environmental dilemma: high-nutritional feeds produce greater insect yields but carry heavier ecological footprints, while low-quality, manure-based alternatives offer reduced impacts but lower productivity⁸⁶.

The organic waste utilization scenario faces additional challenges, including underdeveloped collection systems and supply chain logistics. EU food safety regulations further complicate matters by prohibiting approximately 70% of available food waste as insect farming substrate⁹¹. These restrictions stem from legitimate food safety concerns under Regulation (EU) 2017/893⁹², which prohibits the use of catering waste, kitchen waste, and food waste containing meat or fish products as feed for farmed insects intended for food or feed applications. Moreover, competition from established sectors already utilizing organic waste, such as biogas production and conventional animal feed, raises further questions about resource availability for insect farming⁹³. Thévenot et al.⁹⁴ caution that an emerging insect supply chain could intensify competition for raw materials and byproducts, potentially exacerbating environmental impacts across other agricultural systems.

From a biodiversity perspective, insect farming poses several ecological risks. Escaped farmed insects could potentially disrupt local ecosystems by competing with native species or introducing modified genes into wild populations^83,95. Farmed insects might also serve as vectors for novel pathogens and diseases, threatening native fauna⁹⁵. Recent evidence confirms these concerns are not merely theoretical, as genes selected for commercial traits in farmed insects have already been detected in wild black soldier fly larvae populations across Europe⁹⁶. These concerns have prompted ecological researchers to advocate caution regarding the use of non-native species or genetically modified insects in commercial food production systems⁹⁷.

Overall, while early assessments of insect farming appeared promising, these relied on optimistic assumptions, particularly regarding the use of food waste as substrate, that have proven difficult to realize under commercial conditions. More recent studies incorporating realistic production constraints, including reliance on agricultural co-products, heating requirements in temperate climates, and regulatory restrictions on waste substrates, reveal limited environmental promise in Western contexts. Different conclusions might, however, emerge in tropical regions with alternative production systems and regulatory environments. Table 1 provides a comparative summary of the environmental performance across all four alternative protein sources.

Table 1.

Comparative environmental performance summary of alternative protein sources

Criterion	Plant-based meats	Single-cell proteins	Cultivated meat	Insects
GHG emissions	+++	++	+	±ᵃ
Land use	+++	+++	+++	++
Water use	++	? (insufficient data)	-	±
Energy consumption	++	--	---	-
Eutrophication and toxicity	++	?	±ᵇ	±
Context dependency	Low	High (energy grid)	High (energy, medium)	High (climate, feed)
Data reliability	+++ (empirical)	+ (limited or theoretical)	+ (theoretical)ᶜ	++ (emerging empirical)
Overall environmental promise	High	Moderate to High (with low-carbon energy)	Moderate (major uncertainties)	Low (in temperate climates)

+++ Excellent; ++ Very good; + Good; ± Mixed/uncertain; - Poor; -- Very poor; --- Problematic;? Insufficient data.

ᵃRecent studies, such as Ricardo⁸⁴ assessment, show 12.9–30.1 kg CO₂-eq/kg protein, challenging earlier optimistic estimates.

ᵇCM shows lower marine eutrophication but higher freshwater eutrophication and terrestrial ecotoxicity compared to poultry (few studies available).

ᶜAssessments based on laboratory or pilot-scale projections without commercial validation.

Production scalability

PBMs currently dominate the alternative protein market. In 2023, global retail sales of PBM and seafood were estimated to reach $6.4 billion, up from $5.6 billion in 2022, representing approximately 1% of the total meat market size. The high price of PBMs is often presented as one of the main reasons limiting their purchase. In 2024, adjusting for weight, Battle et al.⁹⁸ found that the average price premium was 82% for PBMs and seafood (see Fig. 3). Springmann⁴⁶ noted that veggie burgers were on average 36% more expensive per serving in high-income countries than beef burgers, veggie sausages were 41% more expensive than pork sausages, and veggie bacon was 99% more expensive than pork bacon.

Fig. 3. Price comparison between plant-based and conventional animal-based products by weight (data from Battle et al.⁹⁸).

Plant-based meats prices per pound are based on frozen and refrigerated plant-based meats subcategories from SPINS year ending 12/17/24. Animal-based meat prices per pound are based on data for fresh meat subcategories from the Census year ending 12/24.

The economics of PBM scalability benefit from utilizing existing food processing infrastructure⁹⁹, significantly reducing capital requirements compared to other alternatives. Nevertheless, the industry confronts challenges in input cost volatility, particularly for specialty ingredients like pea protein isolates. The cost structure encompasses substantial R&D and marketing expenditures characteristic of emerging food categories, while manufacturing costs primarily stem from ingredient costs, especially proteins and oils. As production volumes grow, economies of scale are anticipated in procurement, manufacturing efficiency, and overhead cost distribution.

Troya et al.¹⁰⁰ projected that, based on sales trends from 2017 to 2019, PBM sales would experience an average annual increase of 18%. This would result in a market share of approximately 6% of the global meat market by 2030, with an estimated production of 25 million metric tonnes. While recent slowdowns in sales suggest this target will not be achieved, the report nevertheless highlights key areas of concern for scaling up PBM production, such as the availability of some commonly used ingredients in PBM formulations (coconut oil, pea proteins) or sidestream utilization. The report estimated that the PBM industry must invest at least $27 billion to meet the projected production target of 25 MMT. This level of investment, although considerable, would not be unprecedented¹⁰⁰.

Despite these challenges, PBMs offer great prospects for scaling up. The price gap between PBMs and conventional meat has already narrowed, and there are good reasons to believe this will continue. For instance, investments in R&D aimed at identifying and adapting new crops for PBM production, or the use of specific by-products or waste from plant crops, can contribute to cost reduction.

Mycoprotein-based products have been available on the market for decades under the Quorn brand. However, their prices remain above the average price of meat in retail stores. The economic viability of SCPs is closely tied to input costs, particularly energy and feedstock prices¹⁰¹. While process optimization and increased scale could reduce production costs, achieving price parity with conventional meat would require significant technological improvements in fermentation efficiency and reduced energy consumption. The mature position of companies like Quorn demonstrates that profitable production is possible, though reaching cost competitiveness with the cheapest meats remains challenging.

One of the very few TEAs on mycoproteins estimated a production cost of $3.55/kg for mycoproteins¹⁰². For comparison, according to market data, soy protein isolates traded at prices ranging from 1.8 to 8.1 €/kg protein between 2019 and 2023, while pea protein isolates commanded prices between 3.5 and 9.3 €/kg protein from 2020 to 2023. Wikandari et al.¹⁰³ noted that the use of lignocellulose and advanced fermentation technologies could increase the economic feasibility of mycoproteins. Cost reduction could also be possible through the use of fermentation processes, enabling the use of lower-cost feedstock or cheaper growth medium components¹⁰¹.

Very little data is available for PtF. Leger et al.⁶⁵ attempt an estimate based on a hypothetical process using solar panels and DACs and arrive at a production cost of $4–$5 per kg-protein. More recently, Fasihi et al.⁶⁷ predict a cost for PtF of 5.5–6.1 € /kg in 2028, dropping to 2.1–2.3 €/kg by 2050, thanks to advances in renewable energy technologies. Those figures can be compared to soy and pea isolates, which are the main plant-based protein-rich food ingredients with comparable functionality.

Insect production for human consumption confronts multiple economic barriers. Research on scaling up insect farming for human food markets remains scarce, as the prospects are generally considered limited, and their market share “negligible”¹⁰⁴. Nevertheless, challenges observed in rearing insects for animal feed provide valuable insights into potential obstacles facing human consumption applications, with the economic viability of both sectors sharing some similar concerns as highlighted by recent scrutiny¹⁷.

While it is commonly assumed that insect production costs will decrease as waste substrate usage expands, such projections typically overlook significant challenges in utilizing large quantities of waste materials^76,93. Consequently, insect farming companies tend to rely on substrates already widely employed in conventional animal feed^85,105. Using suboptimal feed substrates such as municipal waste extends insect growth cycles, inevitably compromising economic viability by limiting annual production cycles. Conversely, higher-quality inputs often correlate with increased environmental burdens, creating an inherent trade-off between production efficiency and environmental impact⁸⁶.

Energy requirements for maintaining optimal temperatures constitute another major expense, as insects require high temperatures for efficient growth. While lower temperatures permit development, they extend growth periods and limit production cycles, creating another economic-environmental trade-off. Labor and automation costs further contribute to high production expenses, suggesting insect farming may struggle to achieve economic viability in Western markets while potentially succeeding in Southeast Asia or South America¹⁰⁶.

Optimizing valorization of insect by-products (insect oil and frass) represents one potential avenue for cost mitigation, though prospects remain uncertain¹⁰⁷.

These economic challenges create a complex dynamic in which achieving price competitiveness necessitates industrial-scale production, yet capital investments required for such scaling remain difficult to justify given uncertain demand and unproven cost reduction potential. Consequently, insect products in Western markets may remain confined to premium niches rather than attaining the scale necessary to compete with conventional meat on price.

CM faces the most substantial scalability challenges among all alternatives examined. While CM made its market debut in December 2020, only about half a dozen companies have obtained market authorization so far, and their products remain available in extremely limited quantities. To date, six publicly available TEAs published in academic journals have scrutinized the production process of CM (Table 2), with cost estimates and technical assumptions regarding bioreactor designs, media formulations, cell characteristics, and aseptic requirements, varying dramatically, making direct comparisons challenging. Critical knowledge gaps remain in serum-free differentiation, bioreactor design optimization, CO₂ inhibition at large volumes, and the establishment of food-grade rather than pharmaceutical-grade aseptic standards, all of which significantly impact economic viability and must be addressed before industrial-scale production becomes feasible. As noted by Goodwin et al.²⁷, the current technological status quo does not allow for achieving competitiveness with conventional meat.

Table 2.

Estimated costs for the production of 1 kg of cultivated meat (wet matter)

Study	1 kg production cost estimation
Risner et al.185	$2–$437,000
Vergeer et al.111	$6.43 (optimistic future scenario)–$22,421 (current cost for pessimistic scenario)
Humbird108	$22 (fed-batch + amino acids obtained from hydrolysates)–$51 (perfusion)
Garrison et al.186	$63 (lowest)
Negulescu et al.110	$17 (262,000 L airlift bioreactor)–$35 (stirred tank bioreactor)
Pasitka et al.113	$23.26–$27.24

Data from: Risner et al.¹⁸⁵, Vergeer et al.¹¹¹, Humbird¹⁰⁸, Garrison et al.¹⁸⁶, Negulescu et al.¹¹⁰, and Pasitka et al.¹¹³.

TEAs conducted thus far have consistently highlighted the significance of culture media, particularly growth factors, and to a lesser infrastructure, as the primary cost drivers. Culture media represents 40–99% of production costs across all TEAs. One cost-reduction strategy is therefore to transition from pharma-grade to food-grade ingredients¹⁰⁸. Additional approaches include reducing culture medium usage by optimizing cell feed conversion ratios, media recycling, improving cell metabolism efficiency, increasing cell densities, and developing engineered cells that require fewer growth factors. For instance, Stout et al.¹⁰⁹ demonstrated that autocrine signaling could significantly reduce or eliminate the need for exogenous FGF2 in cultured meat production. These opportunities for reducing media costs would simultaneously decrease environmental impacts through more efficient resource utilization.

Beyond media costs, scaling CM production faces unique economic challenges related to capital intensity. To replace just 1% of the US beef market (approximately 121 million kg/year), CAPEX estimates range from $1.58 billion¹¹⁰ to $4.84–5.45 billion^108,111. The type of bioreactor, its size, and construction materials significantly influence these infrastructure costs¹⁰⁸. Negulescu et al.¹¹⁰ found that airlift bioreactors may be preferable to stirred tank reactors at volumes exceeding 20,000 L due to their uniform shear stress, elimination of impellers, lower purchase costs at scale, and greater energy efficiency during operation. However, critical limitations like CO₂ inhibition may constrain maximum bioreactor volumes. Humbird¹⁰⁸ concluded that 50,000 L represents an optimal size threshold, while Negulescu’s model¹¹⁰ assumed no negative impacts from CO₂ buildup, enabling scale-up to 262,000 L with increasing cost efficiency. These specialized facilities represent substantial fixed costs that must be amortized over production volumes, creating a circular problem where cost reductions require scale, but achieving scale requires costs to already be competitive.

The high cost associated with CM production, even under optimistic scenarios, raises concerns about production scalability in the upcoming years. Moreover, to meet the capacity requirements for 1.5 MMT of CM (approximately 0.4% of the projected 2030 market), the needed infrastructure capacity would be approximately 22 times that of the current global pharmaceutical industry¹¹². Due to these factors, CM is expected to primarily enter the market in the form of plant-based and animal cells hybrid products.

Recent empirical findings demonstrate progress, with a $13.67 price point achieved for 1 kg of hybrid chicken (50% cell-based, 50% plant-based)¹¹³. The remarkable cost reductions were notably achieved through the implementation of continuous manufacturing strategies and the development of a high density, serum-free, albumin-free culture medium priced at $0.63 per litre, notably below the $1 per litre threshold suggested for economic viability. Note that media remains the main cost driver at around 60–70% of the total cost. These initial empirical results support the economic feasibility of CM. However, the known scalability challenges of perfusion culture processes raise questions about the timeline for establishing even a small CM industry, while highlighting the importance of also pursuing realistic short-term strategies in CM production.

Beyond technical and economic challenges, regulatory barriers might represent a significant scalability constraint for CM. To date, only a handful of companies have obtained market authorization globally, with regulatory approval limited to Singapore (2020), the United States (2022), and a few other jurisdictions. The regulatory pathway remains unclear in most markets, including the European Union, where novel food regulations require extensive safety assessments that can take several years and cost millions of euros¹¹⁴. Table 3 summarizes the comparative scalability assessment across all four alternative protein sources.

Table 3.

Comparative production scalability assessment of alternative protein sources

Criterion	Plant-based meats	Single-cell proteins	Cultivated meat	Insects
Current market maturity	++	+ (mycoproteins established in some countries; PtF pilot stage)	---	-- (minimal food market)
Technical readiness	++	+ (mycoproteins proven; PtF unvalidated)	-	+
Infrastructure requirements	++	+	---ᵃ	±
Current cost and cost reduction potential	++	+ (uncertainty around PtF)	±ᵇ	-ᶜ
Overall scalability potential	High	Moderate	Low	Low

++ Very good; + Good; ± Mixed/uncertain; - Poor; -- Very poor; --- Highly problematic.

ᵃRequires ~22× current global pharmaceutical bioreactor capacity to reach 0.4% of 2030 meat market¹¹².

ᵇRecent empirical progress: $13.67/kg for hybrid (50% cells) products¹¹³; wide TEA uncertainty reflects major assumption dependencies.

ᶜCosts exceed conventional meat in Western markets due to heating requirements, labor costs, and substrate competition. Limited cost-reduction potential due to structural constraints in temperate climates¹⁷, though tropical regions may offer better economics.

Acceptability

PBMs benefit from the highest consumer acceptance among novel alternatives. A key rationale driving PBM development is the notion that consumers will be more receptive to plant-based options resembling conventional animal products. Several studies appear to support this hypothesis^98,115,116. Nonetheless, when presented with choices, consumers still tend to favor traditional meat. Findings from blind consumer preference tests on PBMs versus conventional meat are mixed: while one study suggests PBMs can be preferred over traditional meat products¹¹⁷, others demonstrate a clear preference for conventional meat for most products^118,119. These results can plausibly be explained by the great heterogeneity of the products available and their quality. This preference for “meaty” products can create a tension between maximizing environmental benefits through minimal processing and maximizing consumer acceptability through meat-like sensory properties, which typically require extensive processing.

Direct comparisons indicate that PBMs are the most accepted meat alternatives after unprocessed plant-based proteins such as lentils and peas^13,49. For instance, in a questionnaire addressed to UK consumers, 60% were willing to try plant-based proteins, compared to 34% for CM and 26% for insects¹²⁰. Likewise, Stubelj et al.¹²¹ report that in Slovenia, around 66% of respondents would accept plant proteins, but only 21–23% would accept insects or CM.

Several studies suggest that taste and price are generally the two main reasons that restrict the purchase of PBM, though acceptance patterns vary significantly across different consumer segments and cultural contexts^19,122–125. Further research has highlighted that beyond price and taste, barriers to PBM adoption include perceived inferiority to meat, lack of cooking knowledge, and concerns about processed ingredients^122,123. Environmental motivations are less effective than egocentric motives like health and taste in driving consumer acceptance of alternative proteins¹⁹. Moreover, numerous studies indicate that consumers of PBM alternatives, or those who express a higher propensity to purchase such products, tend to exhibit demographic characteristics that deviate from the general population norms^126,127, including being younger^128,129, having higher levels of educational attainment, and higher income levels⁹⁸. Furthermore, these individuals tend to align more closely with left-wing and liberal political ideologies¹³⁰. These findings, in conjunction with other studies, suggest that the decision to consume PBM alternatives is motivated not solely by considerations of taste and price, but also by a constellation of cultural, social, and psychological determinants.

Moreover, Michel et al.¹³¹ found that familiarity with plant proteins strongly correlates with acceptance, while negative associations are often based on misconceptions that can be addressed through targeted communication. Circus and Robison¹³² demonstrated that emotional attachment to meat is a stronger predictor of resistance to PBMs than stated environmental concerns. This psychological resistance reflects what Bastian and Loughnan¹³³ term the “meat paradox”, the cognitive dissonance arising when individuals care about animal welfare and environmental sustainability yet continue consuming meat. According to their motivational account, societies develop mechanisms to resolve this dissonance through habits, social norms, and cognitive strategies that normalize meat consumption. Testa et al.¹³⁴ provide empirical evidence for this phenomenon among Italian consumers, identifying three distinct segments based on their meat-eating justifications: flexitarians who show minimal rationalization, meat lovers who strongly justify consumption through the “4Ns” (eating meat is Natural, Necessary, Normal, and Nice), and potential flexitarians occupying an intermediate position. Their findings demonstrate that stronger meat-eating justifications correlate with higher consumption frequency and lower acceptance of alternatives, suggesting the need for strategies that address psychological barriers rather than just informational ones.

SCPs remain relatively unknown to consumers, limiting available acceptance data. There are extremely few studies on consumer attitudes to SCP. Van Loo et al.¹³⁵ is a notable exception. In a simulated market scenario based on stated consumer preferences, the study observed that conventional farm-raised beef maintained a dominant 63% market share. Among the alternative protein options, pea-based substitutes were estimated at 14%, and yeast-derived animal-like proteins at 7%. CM emerged as the least preferred alternative, garnering only a 5% projected market share. Another study found that the acceptability of mycoproteins was lower than that of plant-based proteins, but higher than that of CM, with food neophobia being the stronger barrier for the acceptance of mycoproteins¹³⁶. In general, the few studies available show moderate enthusiasm for SCPs.

Demographic factors like younger age and urban residence were associated with more positive perceptions and higher purchase intentions towards mycoprotein products. Dietary patterns also played a role, with self-identified reducetarians exhibiting a greater likelihood of purchasing mycoproteins compared to unrestricted omnivores¹³⁷.

Acceptability is likely to depend very much on the type of SCP. For example, as mycoproteins are often displayed alongside PBMs, it is unclear whether consumers view the few mycoprotein-based products significantly differently from other plant-based alternatives. The question is more complex for other forms of SCPs, such as PtF products, and traditional heuristics that apply to agrifood technologies might also apply to them.

CM is typically one of the least accepted alternative protein sources, along with insects^13,19. Its level of acceptance varies across studies, with some finding it more accepted than insects¹²⁰, while others rank it slightly lower^49,121. A recent meta-analysis by Yu et al.²² synthesizing 48 studies identified that perceptions directly related to CM itself exert the strongest influence on acceptance. Perceived ethicality showed the largest positive effect (r = 0.61), while disgust emerged as the most significant barrier (r = −0.57), followed by concerns about taste (r = 0.55) and safety for consumption (r = 0.52). These effect sizes indicate that emotional and sensory factors play a more decisive role than previously understood.

Enthusiasm for CM exhibits significant heterogeneity across geographical regions, with Asian consumers having a higher willingness to try for both plant-based and lab-grown meat alternatives compared to Europeans^19,128,138. Even among Europeans, differences exist: in France, only one-third of respondents expressed a willingness to consume CM, compared to nearly two-thirds in Poland¹³⁹. Literature reviews have highlighted that acceptance patterns have remained relatively stable since the first public demonstrations of CM, with similar demographic and psychographic factors consistently predicting willingness to try¹⁴⁰.

Disparities in the acceptability of CM can also be attributed to demographic characteristics and personal traits. Broadly speaking, factors such as younger age and male gender tend to favour the willingness to try CM¹²⁸. Furthermore, residing in urban locales¹⁴¹, higher socioeconomic background, and environmental consciousness exert a positive, albeit more modest, influence on the enthusiasm towards CM. Elevated levels of food neophobia, concerns about food safety, and a profound attachment to the perceived naturalness of food are major factors in the rejection of CM^{13,22,121,136,142–145}. The Yu et al.²² meta-analysis confirmed that while demographic factors such as age (r = −0.10), gender (r = −0.09), and income (r = 0.05–0.08) had relatively weak associations with WTC, psychological factors showed much stronger relationships. Food technology neophobia emerged as a particularly strong predictor (r = −0.52), substantially outweighing general food neophobia (r = −0.21). This distinction is crucial as it suggests that resistance stems more from the technological nature of CM rather than simple unfamiliarity with novel foods.

Experimental studies have identified effective strategies to overcome initial resistance. Bryant et al.¹⁴⁶ found that emphasizing the similarities with conventional meat while highlighting environmental benefits can significantly increase acceptance. Moreover, Michel and Siegrist¹⁴⁷ demonstrated that trust in scientific institutions is a crucial factor in acceptance, with consumers who trust scientists being significantly more likely to try CM products. Social image considerations play a different role in acceptance across cultures, suggesting the need for culturally-tailored marketing approaches¹⁴⁸. Other cultural aspects can also be of importance. For instance, determining the halal status of CM is critical for Muslim consumers, as adherence to halal dietary principles constitutes a religious obligation. However, according to Hamdan et al.¹⁴⁹, there is currently no unified consensus among Islamic scholars on the halal status of CM, with divergent viewpoints on issues ranging from the source of stem cells to the theological implications of cellular agriculture.

Proponents of CM claim it can reach consumers unwilling to try plant-based alternatives, complementing rather than competing with them. However, empirical evidence challenges this assumption. Studies like Slade¹⁵⁰ found substantial overlap in consumer segments interested in both products, showing a strong correlation between preferences for plant-based and CM. Bryant and Sanctorum³⁰ confirmed this pattern while also identifying a segment of consumers who might prefer CM over plant-based options. If these substitution patterns with PBMs persist, CM could potentially displace environmentally superior plant-based alternatives rather than conventional meat, creating a net negative impact.

Insect-based foods face the strongest consumer resistance. The literature widely reports very low willingness (<30%) to try insect-based foods¹⁵¹. When compared to other alternative proteins, insects generally rank lowest in consumer acceptability^13,120,152. A substantial portion outrightly rejects entomophagy, with 67% of respondents in a UK survey stating nothing could convince them to try insects. Neophobia and disgust emerge as key barriers impeding the adoption of insect-based proteins^121,151. Research on consumers’ attitudes toward insect-based proteins reveals significant geographic variations, with higher acceptance rates in Africa, Asia, and Latin America compared to Western countries¹⁰⁶.

Dietary patterns also play a role, with omnivores being more open to trying insects, while vegetarians strongly oppose it¹⁵³. While the intent to reduce meat consumption and environmental awareness are sometimes identified as positive predictors of willingness to try insects in some studies, other research contradicts those findings¹⁵¹. It can be noted that familiarity and prior exposure via insect tasting can help alleviate disgust and change perceptions of edibility, while reducing neophobia. Insect-tasting experiences yield high approval rates, suggesting that psychological barriers outweigh sensory ones¹⁵¹.

Certain sociodemographic and behavioral characteristics serve as partial predictors of interest in or aversion towards consuming insects. Males, younger individuals (aged 20–40), those with higher educational attainment, and urban residents exhibit a greater inclination to try insect-based foods^13,151,152. Among sensory attributes, insect visibility emerges as the primary barrier to consumer acceptance. Consequently, acceptability is significantly larger for processed insect-based products versus unprocessed whole insects.

The reluctance to consume insects can also translate into a penalty in terms of the price consumers are prepared to pay for an insect-based alternative¹⁰⁶, which may constitute an additional barrier in a context where the available insect-based food products are often more expensive on average. Moreover, it should be noted that many of the studies that examine the acceptability of insects when processed are based on products that have little to do with meat substitutes, such as pasta or snacks. Finally, processing methods for insect-based foods not only affect their acceptability but also their environmental impact and economic viability¹⁵⁴. There is therefore a potential trade-off between acceptability and environmental impact.

Animal welfare

PBMs and SCPs offer clear animal welfare advantages, assuming farmed animals experience more suffering than pleasure¹⁵⁵. While some have theorized that plant farming’s indirect animal casualties (from machinery, pesticides, etc.) could hypothetically cause greater overall suffering than certain animal-based diets, thorough analysis indicates this hypothesis remains highly improbable¹⁵⁶. The dramatic reduction in animal exploitation achieved through these products represents one significant ethical advantage compared to conventional meat production systems. The smaller amount of land required to produce PBMs compared to conventional meat also suggests that it would have less of an impact on wildlife habitats.

CM presents a more complex, yet promising, ethical profile. The production of CM necessitates the procurement of initial cellular material from a limited number of animals. These cells may be obtained from deceased animals, eggs, or through minimally invasive biopsies that are expected to cause negligible discomfort to the donor animals. The number of animals required for CM production depends critically on cell proliferation capacity and production approach. For methods using adult muscle stem cells requiring repeated sampling, theoretical estimates suggest wide variability: a single biopsy could potentially yield meat equivalent to 20–13,000,000 bovines⁴², with this vast range reflecting uncertainties in biopsy frequency, cell yield, and maximum cell doubling capacity before senescence. Alternatively, production techniques employing immortalized cell lines¹⁵⁷ eliminate the need for regular sampling, potentially reducing animal requirements to minimal viable herd populations for maintaining genetic diversity. Under either approach, the number of animals directly involved in CM production would remain negligible compared to current livestock populations.

It is plausible that animals maintained for periodic cell collection would be afforded superior living conditions comparable to those in animal sanctuaries, as they constitute only a minimal fraction of CM production costs and could potentially serve as advantageous marketing elements for CM enterprises. Under such circumstances, several scholars suggest that the utilization of cell-donor animals could be ethically defensible¹⁵⁸. Nevertheless, Ferrari¹⁵⁹ contends that the majority of studies inadequately address significant ethical implications regarding animal bodies during biopsy procedures and cellular cultivation. Ferrari further asserts that ostensibly unproblematic assumptions regarding consent and donor animals fail to acknowledge that these animals would still be subjected to selective breeding practices, invasive procedures, and potential euthanasia when no longer viable for stem cell harvesting, while their long-term welfare remains largely unaddressed within existing ethical frameworks.

The predominant ethical concern pertaining to CM involves the utilization of FBS, a by-product of the meat industry derived from blood collected from gestating cows at commercial slaughterhouses. It is estimated that approximately 600,000 l of FBS were produced annually around 2012¹⁶⁰. Considering that producing 1 l of serum requires 1–3 calf fetuses, this implies the death of 0.6–1.8 million calf fetuses annually for FBS production. While critics have emphasized CM’s historical reliance on FBS, significant progress has been made in developing serum-free media formulations^43,161. This advancement is driven not only by ethical considerations but also by practical imperatives: FBS exhibits inherent compositional variability between batches, introducing significant uncertainties into cell culture processes; it is produced in limited quantities subject to strict regulation; and it represents a major impediment to achieving price parity with conventional meat¹⁶². Consequently, CM companies have almost universally committed to eliminating FBS from their production processes, with several organizations already reporting successful FBS-free production methods substantiated by regulatory documentation. Irrespective of ethical motivations, it is highly probable that all CM companies will ultimately transition away from FBS dependence when scaling to medium or large volumes. The research initiated by the CM sector for FBS-free culture media, where the cost is an important constraint, is likely to generate positive externalities for other fields utilizing cell culture techniques and accelerate the broader transition to FBS-free media across multiple scientific disciplines.

Insect farming raises unique and unresolved welfare concerns. In contrast to other alternative proteins, insect farming directly uses large numbers of animals. While some scientists contend insects cannot experience pain or states like stress, substantial recent research reaches the opposite conclusion^163–166. It should nonetheless be noted that current research on insect sentience focuses primarily on model species like bumblebees and fruit flies rather than commonly farmed insects like mealworms or black soldier flies.

The welfare assessment of insect farming faces unique methodological challenges distinct from conventional animal welfare evaluation. While established frameworks exist for assessing vertebrate welfare—covering aspects like freedom from hunger, distress, or the ability to express natural behaviors—these frameworks cannot be straightforwardly applied to insects. Additionally, the high-density nature of insect farming makes individual welfare monitoring practically impossible, while standard welfare indicators used for vertebrates (stress hormones, behavioral tests) may not be applicable or meaningful for insects^167–169. Similarly, animal welfare recommendations for insect farming are lacking, and almost no empirical evidence exists to guide producers in practising humane slaughter¹⁷⁰.

Uncertainty about the potential suffering of farmed insects is particularly uncomfortable given the astronomical quantities of insects needed to replace a meaningful proportion of meat. For example, considering that a mealworm weighs about 100–110 mg when harvested¹⁷¹, it would take about 9000 mealworms to obtain one kilogram, while a single beef can provide several hundred kilograms of meat. Despite their almost non-existent contribution to the food system, it is estimated that over 300 billion yellow mealworms are already reared every year¹⁶⁹. As a result, some authors consider it would be preferable to apply a precautionary principle and to consider farmed insects as sentient beings¹⁷². Consequently, despite numerous uncertainties that need to be resolved, consuming insects is, at the very least, a solution that appears to be less ethical than other alternative proteins.

Discussion

Conclusions regarding alternative protein acceptability warrant careful consideration. For instance, consumer acceptability of alternative proteins evolves significantly with familiarity and repeated exposure^19,31,32. This dynamic nature of acceptance has several implications. First, initial low acceptance should not be interpreted as insurmountable resistance, as acceptance patterns consistently improve following tasting experiences and repeated consumption. Second, policies facilitating gradual market introduction and product availability are essential to create opportunities for familiarization. Finally, communication strategies should acknowledge that current survey-based acceptance metrics likely underestimate long-term adoption potential, as most studies measure hypothetical willingness-to-try rather than actual consumption behavior following familiarization.

Moreover, the conclusions of this comparative analysis must be interpreted in light of substantial data uncertainties, particularly for emerging technologies. For CM, environmental and cost assessments rely entirely on theoretical projections and pilot-scale data, with no commercial-scale validation. If key assumptions prove overly optimistic, CM may never reach commercial scale or validate its environmental promises. Conversely, breakthrough innovations in cell line development or medium composition could dramatically improve its prospects. Similarly, for SCPs, particularly PtF approaches, conclusions depend heavily on the future availability of low-carbon electricity; in scenarios where renewable energy scaling lags projections, the environmental advantages could diminish significantly. For PBMs, uncertainties are comparatively minor given extensive empirical data, though long-term consumer acceptance trajectories remain uncertain. These uncertainties underscore that rankings presented here represent current best estimates based on available evidence, not definitive predictions. As emerging technologies mature and empirical data replace theoretical projections, reassessment of these comparative conclusions will be essential. Policymakers should therefore adopt flexible strategies that can adapt as better data emerges, rather than committing irreversibly to specific technological pathways based on current projections.

This multidimensional comparative analysis nonetheless tries to analyze the critical gap identified in our introduction: the absence of systematic head-to-head comparisons needed to guide strategic allocation of limited resources in the alternative protein sector. Results are summarized in Fig. 4. While previous studies have demonstrated that alternative proteins can offer environmental advantages over conventional meat, our analysis emphasizes that success requires viable performance across various dimensions, and critically, that not all alternatives are equally positioned to deliver transformative change.

Fig. 4. Overall performance of alternative proteins.

Qualitative assessment of four alternative protein sources across four key dimensions based on the comprehensive literature review. Performance ratings (high, medium-high, medium, medium-low, low) represent synthetic judgments integrating multiple studies and indicators for each dimension. Environmental performance encompasses greenhouse gas emissions, land use, water consumption, and biodiversity impacts. Production scalability considers current market maturity, technical readiness, cost competitiveness, and infrastructure requirements. Acceptability reflects consumer willingness-to-try, market penetration data, and identified barriers. Animal welfare evaluates both direct impacts (number of animals involved, welfare conditions) and indirect effects (habitat impacts). These ratings should be interpreted as indicative assessments of current evidence rather than quantitative scores, with significant uncertainties remaining, particularly for emerging technologies.

PBMs emerge as the most promising option towards a more sustainable food system. SCPs also show promise, albeit with uncertainties surrounding scalability and acceptability. CM could positively contribute if scaled up and capturing consumers reluctant towards PBMs or SCPs, although huge uncertainties remain. Conversely, insect protein appears least promising due to major acceptance and scalability hurdles, limited environmental benefits, and significant ethical concerns surrounding insect farming practices. These individual assessments of alternative proteins complement dietary optimization studies such as that of Mazac et al.¹⁷³, which suggest that an optimal combination of protein alternatives in a diet could significantly reduce environmental impacts while maintaining nutritional adequacy.

Several important limitations should be acknowledged. First, although this scoping review has attempted to integrate different dimensions, it remains incomplete, in particular because it does not include aspects related to health or food safety¹⁷⁴ due to insufficient data. Nutritional profiles are well-documented for PBMs but extremely limited for some SCPs and almost nonexistent for CM, where assessments rely primarily on theoretical projections. Including these dimensions with current evidence would risk premature conclusions that could mislead policy decisions. However, it can safely be argued that the wide adoption of alternative proteins is likely to significantly decrease the risk of zoonoses and antibiotic resistance, as they could greatly reduce the number of animals used¹⁷⁵. In addition, there are encouraging initial results concerning the health effects of PBMs^{174,176–178}. While research on health impacts remains limited, systematic reviews suggest that insect consumption could offer certain nutritional benefits, though more evidence is needed, particularly regarding food safety aspects¹⁷⁹.

Second, acceptability assessments are predominantly based on studies conducted in high-income Western countries, limiting global generalizability. Acceptance patterns for insects, for instance, differ dramatically between Western countries (where rejection is widespread) and Asian, African, and Latin American contexts¹⁰⁶.

Third, this review’s framing of conventional meat production focuses primarily on the environmental and ethical challenges of intensive industrial systems, which dominate production in high-income countries where alternative proteins are being developed. However, livestock systems are diverse, and it is important to acknowledge that certain forms of animal agriculture, particularly extensive pastoral systems, provide benefits not addressed in this analysis. Extensive grazing on marginal lands unsuitable for crop cultivation can deliver valuable ecosystem services, including maintenance of grassland biodiversity, prevention of shrub encroachment, and soil carbon sequestration when appropriately managed^180,181. These extensive systems also represent crucial socio-economic and cultural pillars for many rural communities worldwide, providing livelihoods, cultural identity, and economic stability that cannot be straightforwardly replaced by alternative protein production. A comprehensive transition strategy must therefore consider not only the comparative performance of protein alternatives but also the diverse roles of existing livestock systems and the complex socio-economic dimensions of rural transformation.

Another significant limitation of this literature review, applicable across all alternative proteins examined but particularly acute for those requiring substantial technological innovation, lies in its reliance on publicly available studies. This constraint primarily affects the environmental impact and scalability assessments, which directly depend on production processes and recent technological advances, while minimally influencing the acceptability and animal welfare sections. Given the intensely competitive landscape, alternative protein companies frequently withhold information regarding their latest technological breakthroughs until securing intellectual property protection or achieving sufficient market readiness. Consequently, scientific research efforts encounter substantial barriers when attempting to model environmental impacts or production costs, as they lack access to the most current data and technologies employed by industry leaders.

Additionally, this paper did not investigate the extent to which alternative proteins actually displace conventional meat consumption. Limited research on this subject precludes definitive conclusions. While NPD’s SupplyTrack service found that three-quarters of increased meat alternative sales in U.S. foodservice channels displaced animal protein sales¹⁰⁰, other evidence suggests minimal displacement effects for beef^16,182. Nevertheless, improving PBM affordability appears to represent a strategic lever potentially promoting greater interest in and selection of sustainable food choices¹⁸, though substantial gaps remain between technological potential and commercial reality, particularly for emerging technologies.

Despite such limits, the value of this multidimensional comparative approach extends beyond academic contribution. As the alternative protein sector consolidates and investors and policymakers face difficult decisions about resource allocation, evidence-based frameworks for comparing alternatives become essential. This review can therefore inform several key policy recommendations:

Research and development priorities: public funding should strategically target PBMs and SCP development, prioritizing improvements in sensory appeal and cost competitiveness relative to conventional meat.

Market development mechanisms: public procurement policies could accelerate market adoption by incorporating alternative proteins into institutional food services such as schools, hospitals, and government facilities, creating familiarity and stable demand that supports industry scaling.

Agricultural transition support: given alternative proteins’ reduced land requirements, policymakers should develop incentives for repurposing land spared from animal agriculture toward carbon sequestration or environmental restoration, potentially remunerating farmers who convert former livestock lands into carbon sinks and restored natural landscapes¹⁸³. Targeted support for farmers transitioning from livestock to alternative protein crop production (such as pulses for plant-based proteins or feedstocks for fermentation) could ease rural economic transitions while maintaining agricultural livelihoods.

Economic instruments: internalizing conventional meat’s negative externalities through pricing mechanisms while redirecting existing livestock subsidies toward alternative protein development¹⁰ could create a more level playing field that reflects true production costs.

International cooperation: coordinated action on standards, trade agreements, and technology transfer could accelerate global adoption of sustainable protein systems, particularly supporting developing nations in leapfrogging conventional intensive animal agriculture.

Methods

Literature search strategy

This literature review employed three primary databases: Google Scholar (GS), Web of Science (WoS), and the USDA National Agricultural Library database (SEARCH). The studies were obtained through searches conducted between April 2024 and July 2025 using specific search expressions across the four analytical dimensions (environmental impact, production scalability, consumer acceptability, and animal welfare) for each alternative protein category. The complete list of search terms is detailed in Supplementary Data 1. Google Scholar and Web of Science were utilized as generalist databases offering complementary coverage¹⁸⁴, with Google Scholar indexing a broader range of publication types, including conference proceedings, theses, and technical reports that are often excluded from traditional academic databases. The USDA National Agricultural Library database was consulted for its specialized coverage of agricultural literature, incorporating results from the Catalog and Articles database (AGRICOLA), PubAg, and the NAL Digital Collections (NALDC).

Screening and selection criteria

As alternative proteins are a new and rapidly evolving topic, it was considered that earlier studies would not be sufficiently recent to provide reliable information. Therefore, studies published before 2015 were excluded from the screening phase. Considering studies up to July 2025, while excluding studies published before 2015, the number of results obtained reached 9093. However, these results include a large number of duplicates, due to studies appearing in more than one search, and because of overlaps between WoS, GS, and SEARCH. After removing these duplicates, 4561 documents remained. Many studies on insects and SCPs focused on animal feed and were therefore outside the scope of this review. By excluding papers with the term “animal feed” but without the mention of “food” from the results, only 4178 documents remained.

Each article and report was then manually screened. Firstly, by reading the title, which reduced the number of studies from 4178 to 1156, and then by reading the abstract, which further reduced the number of studies to 891. Additional references were identified through systematic monitoring of grey literature sources. RSS feeds and newsletters from organizations actively engaged in alternative protein research and industry development were monitored throughout the study period, including the Good Food Institute, Green Queen Media, and Food Navigator. These sources were selected for their comprehensive coverage of both academic and industry developments, providing access to reports, white papers, and industry analyses not typically indexed in academic databases. Given the nature of the alternative protein sector, where significant developments and evaluations often appear first in industry reports before academic publication, incorporating these grey literature sources was essential for capturing the current state of the field. References were also found by consulting the reference lists of documents read as part of this review, following standard snowballing methodology. Finally, some resources were also shared by colleagues working on alternative proteins through academic networks. The resources consulted were all written in French or English. These additions bring the total number of studies considered to 929. These 929 studies are available on a dedicated Notion page, which can be accessed via the following link: https://spiny-platypus-e52.notion.site/Bibliography-Comparing-the-potential-of-meat-alternatives-for-a-more-sustainable-food-system-bcb6a87c8040496d98d6d5d848435f70?pvs=4.

Of the 929 studies identified, a final selection of 203 references was made for this review. Figure 5 provides a summary of the methods used to identify and screen the documents considered in this review, and Supplementary Data 1 provides a detailed mapping of how the final 203 selected references were distributed across the four analytical dimensions and four alternative protein categories, revealing the research density for each combination.

Fig. 5. Flowchart of the literature search and screening process.

The left panel shows identification of studies via databases: records were identified from Web of Science (n = 4017), Google Scholar (n = 2845), and USDA National Agricultural Library (n = 2231). Before screening, duplicate records (n = 4532) and records containing animal feed (n = 382) were removed, leaving 4179 records for screening. Title screening excluded 3073 records and abstract screening excluded 214 records, resulting in 892 records assessed for eligibility. Of these, 726 records were excluded but kept in Notion for reference. The right panel shows identification of studies via other methods: records were identified through monitoring of the new literature (n = 17), recommendations from colleagues sent by colleagues (n = 5), citation searching (n = 14), and suggestions from reviewers (n = 2), yielding 38 additional records assessed for eligibility. Both pathways combined resulted in 204 citations included in the final review.

The selection of the final 203 references from the 929 identified studies was guided by several quality considerations. Particular attention was given to recent systematic reviews and meta-analyses, which provide robust syntheses of existing literature on alternative proteins and helped establish a general framework and identify key trends in each field studied. These were complemented by primary studies selected for their specific contribution to understanding the four dimensions analyzed. Preference was given to peer-reviewed publications with transparent methodologies and clear data sources. When available, empirical data from operational facilities or completed trials were prioritized over theoretical projections. However, for emerging technologies, particularly CM and PtF approaches, empirical evidence remains scarce, and theoretical modeling studies or pilot-scale assessments often represent the best available evidence, with their inherent uncertainties explicitly acknowledged throughout the analysis. For life cycle assessment studies, preference was given to those clearly specifying system boundaries, functional units, and key assumptions about production processes and energy sources. The assumptions underlying LCA studies were examined, and those with assumptions most closely aligned with current industry practices were prioritized. Studies providing comparative assessments between multiple alternative proteins or between alternatives and conventional meat were particularly valued for enabling direct comparisons. Consumer acceptance studies were evaluated based on sample size, geographic coverage, and whether they incorporated actual tasting experiences versus hypothetical willingness measures, though it should be noted that for products not yet commercially available, reliance on hypothetical acceptance measures was unavoidable. Regarding scalability assessments, studies providing data on current production costs, infrastructure requirements, or input availability were favored. For TEAs, particularly those on emerging technologies, the scarcity of available studies meant that all peer-reviewed TEAs were included regardless of methodological variations. The timeliness of data was considered essential, favoring the most recent studies in each rapidly evolving domain, though older but widely cited publications were included when they presented fundamental results that significantly influenced the field. Industry reports and grey literature were incorporated when they provided access to primary production data or market insights that are often unavailable in academic publications due to the competitive nature of the sector. Attention was paid to funding sources, with a critical examination of research funded by the alternative protein industry. While such industry-funded studies require careful scrutiny for potential bias, they nonetheless provide valuable access to primary production data and real-world operational insights that are difficult to obtain elsewhere. Studies not included in the final selection nevertheless contributed to validating the observed trends and ensuring the comprehensiveness of the review.

As a non-native English speaker, the author used Claude (Anthropic), a large language model, to improve the clarity and fluency of the manuscript. The AI assistance was limited to language editing and stylistic improvements, including grammar correction, vocabulary enhancement, and sentence structure optimization. All scientific content, analysis, interpretations, and conclusions remain entirely the author’s own work. The use of this AI tool was solely for linguistic improvement and did not involve content generation or analysis of research findings.

Author contributions

T.B.C. conceptualized the study, conducted the literature review, analyzed the data, and wrote the manuscript.

Data availability

No datasets were generated or analysed during the current study.

Competing interests

The authors declare no competing interests.

Supplementary information

The online version contains supplementary material available at 10.1038/s41538-025-00694-3.