A systematic review of the definitions and interpretations in scientific literature of ‘less but better’ meat in high-income settings

‘Less but better’ is a pragmatic approach to tackling the sustainability challenges of meat consumption and production. Definitions of ‘less’ and ‘better’ lack clarity. Here we explore interpretations of these concepts, finding increasing use of ‘less but better’ in the literature from Western, high-income settings. Despite discrepancies among interpretations of ‘less’ meat, existing quantifications indicate that significant reduction is needed to achieve desirable food system outcomes. Interpretations of ‘better’ meat incorporate the delivery of environmental sustainability, improved animal welfare and better health or nutrition, but lack clear principles and omit many sustainability themes. Practices and outcomes are seldom linked, and diverging narratives on interactions between ‘less’ and ‘better’ exist. A shared vision of livestock systems with improved sustainability across multiple indicators is needed to establish principles for ‘less but better’ in order for decision-making to deliver desired outcomes. The concept of ‘less but better’ meat lacks clarity. A shared vision of livestock systems and meat consumption needs to be outlined to guide decision-makers towards food system sustainability.

T he global food system is the source of many and diverse environmental and social pressures [1][2][3] . To respect planetary boundaries while providing adequate and nutritious food for all necessitates production improvements, waste reduction and transformation of dietary patterns [3][4][5] . Increasing incomes, urbanization 6 and Westernization of diets 7-10 have led to a global increase in annual meat consumption from 23 kg per person in 1961 to 43 kg per person in 2018 (slaughter weight 11 ), but with considerable regional differences. In high-income countries, consumption of meat needs to be drastically reduced 3,5 and there is extensive literature comparing the environmental impact of meats versus other foods 2,12-15 and the impact of different diets 3,4,[16][17][18] . The exact magnitudes of reductions, and how to attain these, is a source of debate within academia [19][20][21][22] , popular media 23,24 and policy-making circles 25 .
To eat and produce 'less but better' meat has been suggested by researchers 26 and non-governmental organizations [27][28][29][30][31] as a more politically feasible strategy than calling solely for meat reduction. Previous research has shown that 'less but better' meat is a concept in need of clarity, since how much 'less' is, and what 'better' should deliver depends among other things on the sustainability aspects considered, the local context and the desirable outcomes of the food system 32 . In this study we systematically review uses, definitions and interpretations of the concept in peer-reviewed scientific literature. We focus specifically on the 'less but better' concept, rather than intending to review all the literature on sustainability issues of livestock, as existing literature is scattered.

Results
Study selection and characteristics. We identified 35 studies for inclusion ( Fig. 1) based on the eligibility criteria (see Methods section). 'Less but better' has received greater attention in recent years. Two-thirds (n = 24) of the articles were published between 2018 and 2021 (Supplementary Table 1), and all (bar one) by authors in Europe, the United States or Australia, demonstrating that this concept is most used in Western, high-income settings-where overconsumption of meat and dairy is greatest 11 , and where a shift to more sustainable diets underpinned by sustainable production is most pressing. The majority of selected articles focus on consumption (n = 23), including consumer acceptance and choice, although a significant number of articles span both production and consumption (n = 11). Just one article focuses principally on production 33 . None of the included articles stated defining 'less but better' as a research aim.
Linkages and contradictions between these two types of definitions were apparent. Grass-feeding livestock could facilitate increased resource efficiency (that is, environmental sustainability) 33 . However, feedlot systems could perform most favourably if the desired outcome is reducing land use per kilogram of meat produced 2 . Practices that improve animal welfare are largely overlooked, except reduced stocking densities 53,56 . There is a lack of evidence regarding farming practices that improve nutritional quality. One paper for example claims "the nutrients are different" in free-range meat 49 , but without evidence to support this.
How much is 'less'? All papers referenced the need for reduced consumption (Supplementary Table 2), but only eight quantified this. Quantifications were primarily relative, used different units (for example, grams of food versus protein) and definitions (animal-sourced foods versus animal protein versus meat). Recommendations on limiting consumption ranged from 9 to 105 g A systematic review of the definitions and interpretations in scientific literature of 'less but better' meat in high-income settings Kajsa Resare Sahlin 1,3 ✉ and Joanna Trewern 2,3 'Less but better' is a pragmatic approach to tackling the sustainability challenges of meat consumption and production. Definitions of 'less' and 'better' lack clarity. Here we explore interpretations of these concepts, finding increasing use of 'less but better' in the literature from Western, high-income settings. Despite discrepancies among interpretations of 'less' meat, existing quantifications indicate that significant reduction is needed to achieve desirable food system outcomes. Interpretations of 'better' meat incorporate the delivery of environmental sustainability, improved animal welfare and better health or nutrition, but lack clear principles and omit many sustainability themes. Practices and outcomes are seldom linked, and diverging narratives on interactions between 'less' and 'better' exist. A shared vision of livestock systems with improved sustainability across multiple indicators is needed to establish principles for 'less but better' in order for decision-making to deliver desired outcomes.
per capita per day ( Fig. 3) 38,41,44,45,57,58 . One study provides an absolute quantification, suggesting that livestock on ecological leftovers could globally provide 9-23 g per capita per day of animal-sourced protein (including milk and eggs), covering 16-42% of average daily protein requirements 33 . Studies seldom stated which meat types were included or whether figures referred to slaughter or cooked weight, despite these factors having an influence on sustainability impacts.
Many other sustainability aspects were underdiscussed. Biodiversity was mentioned frequently, but rarely as a criterion for 'better' , including grazing for promoting biodiversity 22,36 . Health or nutrition were referenced frequently concerning 'less' meat. In relation to 'better' , fat content 40,58,59 and public health issues such as air quality associated with intensive production were cited 22,42 . Other aspects, such as digestibility, iron and vitamin B12 were absent. Freshwater use 26,35,54 and nutrient balance or eutrophication 33,50,51 each appeared in three papers. Views on hormones, antimicrobials and genetically modified organisms ranged from negative for public health 42 to positive for efficiency 35 . Social and economic sustainability aspects were largely missing. No articles dealt with matters of well-being, working conditions or governance. Maintenance of rural landscapes was mentioned twice 36,52 . One paper called for "socially acceptable" production 41 while another pointed to the importance of ensuring that meat reduction strategies do not negatively impact farmers 63 . Financial risks of intensive systems appeared once 53 . The most frequently discussed socioeconomic aspect was the importance of close relationships between consumers and producers 46,47,50,51 , including consumers perceiving meat bought at a local butcher as 'better' 46,54,58 . High-and low-quality meat was often referred to but not defined. One paper reported that Chinese consumers prefer industrially produced meat which they associate with quality and safety 65 .
Most articles (n = 24) on 'less but better' mentioned a specific farming system (Table 1). This reveals a dominant narrative in the literature that 'better' meat comes from extensive, mixed, local systems that use few, if any, external inputs such as feeds and chemicals. Whether these forms of production constitute more sustainable farming has been studied by many [66][67][68][69][70][71] , but was also criticized as a "rose-tinted view(s) of traditional food production" because of the higher emission intensities, land use and water use of extensive beef and pork 35 . This dispute between organic/nature-based solutions or intensification 72,73 as 'better' is commonly referred to as 'land sharing' and 'land sparing' 74,75 , and sustainability impacts are widely debated. Both approaches would, however, require a shift in diets, that is 'less' meat 67,68,71,76 .
Organic could be considered to deliver 'better' because organic labels are the most recognized cues available to consumers. For example: "As Dutch consumers had no shopping-aid to distinguish grass-fed meat … 'better' meat was defined as 'organic or free range meat'" 26 . This indicates that fully grass-fed meat is considered 'better' than organic, although few articles presented it as such (Table 1). Consumers opting for organic are found to adhere more to other sustainability-promoting behaviours such as eating less meat 26,54,77 , although the underlying drivers of this relationship are unclear.
A systems perspective on 'better' meat. Most papers focused on single actors or scales, or interactions between two actors (for example, producer-consumer relations). Only two studies addressed  system-level aspects, for example, that beef from dairy rather than suckler herds can be a 'better' option, both considering the climate impact of the meat and the resource efficiency of the food system 53 .
The structural dynamics of the current, highly globalized meat production system also has implications for 'better' 50 . Industrialization has, among other factors, caused concentration of livestock in certain regions, resulting in eutrophication, pollution, overgrazing and land abandonment, and a more localized, circular production system could therefore be a 'better' option 50 .
Interactions between 'less' and 'better' . A strength of 'less but better' is its consideration of both production and consumption, supporting the identification of trade-offs and win-win outcomes. We found several interactions between 'less' and 'better' with implications for dissonance or coherence between scales (Fig. 5). 'Less' was sometimes seen as a prerequisite for 'better'-for example, "the significant reduction of farm animal production … in order to improve the production standards for the remaining animals" 41 . 'Less for better' at local scale could address localized impacts of livestock production, but unless national consumption is reduced, this strategy risks offshoring food production impacts and increasing reliance on imported goods.
Another interpretation was that the 'better' option is to eat 'less' meat ('less as better'), with improvements to production as a secondary goal. There are commercial challenges in promoting 'less' without 'better' and a concerted societal effort including policy interventions would be needed to enable this 26,57 . This view also neglects that food's environmental impacts primarily occur at the production stage 2 . Food is often heralded as holding the potential to deliver multiple Sustainable Development Goals, including addressing climate change and biodiversity loss 78 . Without a focus on production, it is difficult to see how this could be realized, and 'less and worse' can hardly be desirable.
A conflicting narrative defined 'better' as meat with lower emissions intensity per unit of output (sustainable intensification), which would allow for unchanged consumption, that is, 'better' without 'less' 60 . This, however, ignores the need to reduce high-income meat consumption, for example, to meet the 1.5 °C climate goal 3,79,80 and metrics per kilogram of product or protein seldom account for sustainability trade-offs and complexity. 'Better' without 'less' could "agro-ecological and smallholder farming methods" -Broad 48 , Treich 55 "extensive production, such as organic or free-range" -Jurgilevich et al. 50 "products from grass-fed organic farms and avoiding feedlots" -McGregor and Houston 52 "improved animal welfare, environmental impacts, or nutritional quality" -Capper 35 Practices Outcomes "socially accepted and thus animal welfare-oriented" -Hölker et al. 41 "highly efficient in terms of resources (more sustainable) and with minimised health consequences (healthier)" -Pais et al. 45 ? Fig. 2 45 Trewern et al. 57

Fig. 3 | Standardization of (explicit and implicit) descriptions of 'less' among included articles.
All values have been recalculated to grams of meat protein per person per day using a 20% protein content in meat (see Supplementary Information for data) except the figure in neff et al. 44 , which includes eggs and refers to a daily recommended intake limit (grey bar). The shaded bars for van Zanten et al. 33 and de Boer and Aiking 38 indicate that these articles describe 'less' as ranges.
'Empowered consumers' willing to reduce their meat consumption are often highly educated, women and/or from high-income households 44,58,59 , and are a minority of the population 26,58,59 . They tend to be less price sensitive than 'average' consumers 47,59 , giving "these more conscious forms of food consumption … a distinctive middle-class appeal" 52 . Speaking in favour of the potential of 'less and better' is the combination of reducing consumption and eating meat of higher quality as consumers could maintain current spending while improving sustainability 22,39,43 . This makes 'less but better' a more acceptable message than 'eat no meat' 22,61 . Whether higher prices would drive sufficient meat reduction is, however, unclear 44 -high-income consumers can probably afford to maintain consumption anyway 44,54 , and meat-loving consumers are often driven by taste and eating quality 47,58 . A strong personal interest is thus become a cover-up for business-as-usual and an attempt at greenwashing.

discussion
One criticism of 'less but better' is that it puts responsibility on consumers to make sustainable, ethical or 'better' choices rather than recognizing issues caused by capitalist agrifood systems (refs. [81][82][83][84] in ref. 64 ), thus depoliticizing the issue. Without clear definitions of 'less' or 'better' , the concept cannot place responsibility where responsibility is due. Among the included articles, very few address how value-chain actors beyond producers and consumers ought to facilitate 'less and better' (except 57 ). Some interpret 'less but better' as more radical, going hand-in-hand with "food sovereignty's anti-capitalist orientation" requiring "agro-ecological and smallholder farming methods" and "redistributive land reform" 48 .
While relevant in high-income settings, 'less but better' is not suitable for regions where diets are nutritionally inadequate. In these areas, 'more and better' meat may be more relevant 79,80,85 . To stay within planetary boundaries globally, however, a focus on 'less' in overconsuming areas is needed to make room for 'better' in regions where consumption of animal-sourced foods needs to increase. In the FAO's 'Towards Sustainability' 85 scenario, for example, animal herd sizes in high-income countries would decrease by 2030 and further by 2050 while the opposite development would occur in low-income regions. The scenario also postulates that highly productive livestock-rearing practices would have to be abandoned and most regions would have less intensive livestock systems, including a rewilding of 3-4% of arable land in Europe. In-depth analysis of the implications of such transitions for producers was missing in the literature. To enable 'better' at scale, incentives and policy mechanisms such as product labelling, price premiums and fair payment for delivery of public goods are necessary, as is diversification of farm incomes to maintain viable farm businesses when meat production is reduced 70,71 .

Importance of better
Better without less Business as usual Less as better Coupling of 'less' and 'better' is key, either sequentially ('less or better') or simultaneously ('less and better').

Less and better
'Better' options have lower footprints and sustainability challenges can thus be tackled without 'less' consumption.
Neither 'less' nor 'better' is considered relevant for tackling sustainability challenges of production and/or consumption.
The 'better' option is to eat 'less' meat. 'Better' in the form of improved production is secondary.

Fig. 5 | Interactions between 'less' and 'better'. Illustrations of interlinks between 'less' and 'better' based on importance of the two.
Analysis and synthesis of results. Coded text was transferred to a Word document and grouped thematically to allow for analysis of definitions and interpretations 87 . To reduce bias, both authors independently reviewed thematic clusters and looked for emerging narratives. These were then compared and discussed before key results were documented. Quantifications of 'less' were normalized (Supplementary Table 5). We created tables of concept definitions (Supplementary Table 4) and sustainability themes and production systems in the context of 'better' (Table 1  and Supplementary Table 3). Rounds of inductive analysis elicited narratives of interlinkages of 'less' and 'better' .

Risk of bias.
Since this study does not assess the applicability or accuracy of any scientific finding or conducted study, or seek to make any recommendation based on these, but instead seeks to report on existing narratives, the importance of the risk of bias in the included article is not relevant to the findings. To reduce internal biases within the research theme, which risk impacting the exploratory, qualitative approach, we conducted coding and analysis independently and discussed throughout, and moreover took a deductive-inductive approach to ensure results were not restricted by the a priori coding framework. Expanding the search to other languages would probably have yielded more relevant materials; however, in the regions where the concept is most relevant (Western, high-income countries), English is the key language for scientific publication and this limitation is thus justified.
Reporting summary. Further information on research design is available in the Nature Research Reporting Summary linked to this article.

data availability
Data used in this study, including a list of papers reviewed, can be found in the Supplementary Information. required from the consumer to adopt a 'less and better' diet. Policy interventions and commitment from businesses to reduce meat intake and make 'better' options accessible to a broader spectrum of consumers are key to realize the full potential of 'less but better' .
Concluding remarks. The 'less but better' meat concept is increasingly used in the English-language scientific literature, especially in Western, high-income settings. There is, however, a lack of consensus on how much 'less' is, as most studies provide no quantification despite often evaluating the efficacy of meat reduction strategies. Based on existing quantifications (n = 8), 'less' involves a significant reduction from current consumption. The use of different scopes and measures could inhibit progress, and probably creates confusion. Future studies should provide more clarity and transparency around recommendations on 'less' . Ideally, these should encompass all animal-sourced foods, not just meat, given the sustainability impacts of all livestock production.
There is a similar lack of coherence in definitions and interpretations of 'better' . The idea that 'better' meat should deliver 'environmental sustainability' , improved animal welfare and better health outcomes is not accompanied by clear principles, and many key sustainability themes, including social and economic aspects, are absent from discussions. There is a lack of clarity on desirable outcomes from human-livestock interactions and what practices would deliver these at different scales. This missing link between practices and outcomes results in a lack of clarity on 'less but better' , preventing the concept from bridging bodies of literature on meat and sustainability. If the concept is to be used to guide food systems decision-making in policy and industry environments, there is a need to develop principles or best-practice guidelines to ensure alignment and progress toward desired outcomes. More work needs to be done to establish a vision of future livestock production systems that have improved outcomes across sustainability themes and can be agreed on by a wide range of stakeholders.

Methods
We conducted a systematic review of the literature published in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines 86 (Fig. 1).

Protocol and registration.
We did not submit a review protocol to PROSPERO (or similar) because this review does not evaluate the effectiveness of an intervention, test the accuracy of a diagnostic or similar, or aim to synthesize the current state of knowledge regarding the prevalence or incidence of a phenomenon.
Eligibility criteria. After defining the scope and aim of the study, we identified search terms and eligibility criteria ( Table 2). At this stage we sought input from three external independent experts to refine our search strategy.
Information sources. On 2 June 2021 we performed searches on Scopus, Web of Science and Google Scholar to identify relevant scientific literature (step 1, Fig. 1).

Search.
We used the terms 'meat' AND 'less but better' OR 'less and better' and limited the search to peer-reviewed studies published in English since year 2000, which were available as full-text options online.
Study selection. The search yielded 818 entries. We screened titles and abstracts and excluded papers not dealing with meat consumption and reduction, or meat production and livestock (step 2, Fig. 1). We screened the full texts for mention and definition of 'less but better' , 'less and better' or 'less-but-better' (step 3, Fig. 1). To reduce bias, both authors screened independently, and discrepancies during cross-checks were resolved through discussion. A final 36 articles (six correspondence or viewpoints) were included. Resare Sahlin et al. 32 was used as basis for the thematic coding because it is the first paper focusing on defining the concept, thus leaving 35 articles included in the study.
Data collection. We manually coded in Microsoft Excel and Microsoft Word 87 using 37 initial codes based on ref. 32 and 24 codes inductively identified from individual coding of four randomly selected articles. Subsequent comparison and discussion refined the coding framework, based on which we then coded all 35 papers.

Statistics
For all statistical analyses, confirm that the following items are present in the figure legend, table legend, main text, or Methods section.
n/a Confirmed The exact sample size (n) for each experimental group/condition, given as a discrete number and unit of measurement A statement on whether measurements were taken from distinct samples or whether the same sample was measured repeatedly The statistical test(s) used AND whether they are one-or two-sided Only common tests should be described solely by name; describe more complex techniques in the Methods section.
A description of all covariates tested A description of any assumptions or corrections, such as tests of normality and adjustment for multiple comparisons A full description of the statistical parameters including central tendency (e.g. means) or other basic estimates (e.g. regression coefficient) AND variation (e.g. standard deviation) or associated estimates of uncertainty (e.g. confidence intervals) For null hypothesis testing, the test statistic (e.g. F, t, r) with confidence intervals, effect sizes, degrees of freedom and P value noted Data Policy information about availability of data All manuscripts must include a data availability statement. This statement should provide the following information, where applicable: -Accession codes, unique identifiers, or web links for publicly available datasets -A list of figures that have associated raw data -A description of any restrictions on data availability Data used in this study, including a list of papers reviewed, can be found in the Supplementary Material.