The global food system faces significant environmental and social pressures. Meeting nutritional needs while respecting planetary boundaries requires improvements in production, waste reduction, and dietary shifts. High meat consumption in high-income countries necessitates drastic reductions. The 'less but better' meat concept, promoted as a politically feasible strategy, requires clarification as definitions of 'less' and 'better' vary widely depending on the sustainability aspects considered, the local context, and desired food system outcomes. This systematic review examines the uses, definitions, and interpretations of 'less but better' meat in peer-reviewed scientific literature, focusing specifically on this concept rather than the broader literature on livestock sustainability.

Existing literature extensively compares the environmental impacts of different foods and diets, but the magnitude of necessary meat reduction and how to achieve it remain debated. Previous research highlighted the lack of clarity surrounding the 'less but better' concept, emphasizing the context-dependent nature of defining 'less' and 'better'. This review builds upon this prior work by systematically examining the peer-reviewed literature.

A systematic review was conducted following PRISMA guidelines. Searches were performed on Scopus, Web of Science, and Google Scholar using terms such as 'meat' AND 'less but better' OR 'less and better'. Eligibility criteria included studies focusing on meat consumption or production, containing definitions of 'less but better', published in English since 2000, and available as full-text online. Two authors independently screened titles and abstracts, and full texts. Data extraction involved manual coding in Excel and Word using a refined coding framework. Thematic analysis identified definitions and interpretations, and quantifications of 'less' were normalized. Inductive analysis revealed narratives of interlinkages between 'less' and 'better'.

Thirty-five studies were included, primarily published between 2018 and 2021 and authored in Western high-income settings. Most articles defined 'less but better' within their study context or cited external definitions. There was broad agreement that 'less but better' should positively impact animal welfare, human health, and environmental sustainability, but the specific farming practices to achieve these outcomes were rarely specified or evidenced. Definitions of 'better' predominantly focused on outcomes rather than practices. Significant discrepancies existed in defining 'less'. While all papers acknowledged the need for reduced consumption, only eight quantified it, using varying units and definitions (grams of food, protein, animal-sourced foods). Recommendations ranged from 9 to 105 g per capita per day. Interpretations of 'better' varied, frequently mentioning climate impact (lower carbon footprint), land use (grass-fed meat), and animal welfare. However, many sustainability aspects were underdiscussed, including biodiversity, freshwater use, nutrient balance, social, and economic sustainability. A dominant narrative associated 'better' meat with extensive, mixed, local systems, but this was criticized for potentially higher emission intensities and resource use compared to intensification. The relationship between 'less' and 'better' showed dissonance and coherence across scales. Some considered 'less' a prerequisite for 'better', others viewed 'less' as the primary goal. A conflicting narrative proposed 'better' (lower emissions intensity) without 'less' consumption, ignoring the need for meat reduction in high-income settings.

The 'less but better' concept, while relevant in high-income settings, is not suitable for regions with inadequate diets. The study highlights the lack of consensus on quantifying 'less' and defining 'better', hindering the concept's effectiveness. The responsibility for sustainable choices is often placed on consumers, neglecting systemic issues within capitalist agrifood systems. The interlinkages between 'less' and 'better' are complex, with several interpretations, including 'less as better' (reduced consumption being the main priority) and 'better without less' (sustainable intensification allowing for unchanged consumption). The latter risks greenwashing. Empowering consumers to reduce consumption and making 'better' options accessible requires policy interventions and business commitment.

The 'less but better' concept lacks clarity and consensus regarding 'less' and 'better', hindering its use in guiding food systems decision-making. Future research needs to establish principles and best practices, consider all animal-sourced foods, and address social and economic sustainability. A shared vision of future livestock production systems is crucial for aligning progress toward desired outcomes.

The study focuses primarily on English-language literature published in high-income countries, potentially limiting the representation of views from other regions and languages. The qualitative nature of the analysis may have limited the ability to make definitive quantitative statements about the prevalence of different interpretations of 'less but better'.