Abstract
Both the global average per capita consumption of meat and the total amount of meat consumed are rising, driven by increasing average individual incomes and by population growth. The consumption of different types of meat and meat products has substantial effects on people’s health, and livestock production can have major negative effects on the environment. Here, we explore the evidence base for these assertions and the options policy-makers have should they wish to intervene to affect population meat consumption. We highlight where more research is required and the great importance of integrating insights from the natural and social sciences.
Generated Summary
This review article examines the multifaceted impacts of meat consumption on human health, the environment, and the food system. The study explores the rising global meat consumption, driven by increasing incomes and population growth, and investigates the environmental and health consequences. The research employs a review methodology, drawing on a range of scientific literature, including epidemiological studies, life-cycle analyses, and economic models. The scope includes assessing the effects of different types of meat on health outcomes, the environmental impacts of livestock production, and potential interventions to influence meat consumption patterns. The article emphasizes the need for a comprehensive understanding of the complex interplay between individual behaviors, societal norms, and policy interventions to achieve positive outcomes. It delves into drivers of meat consumption, including economic, cultural, and psychological factors, and the role of various stakeholders, such as governments and civil society organizations.
Key Findings & Statistics
- The global average per capita consumption of meat and the total amount of meat consumed are rising.
- Growth rates vary across different regions, with consumption in high-income countries static or declining and in middle-income countries moderately to strongly increasing.
- Meat is a good source of energy and some essential nutrients, including protein and micronutrients.
- In high-income Western countries, studies show that total mortality rates are modestly higher in participants who have high intakes of red and processed meat.
- The strongest evidence for an adverse effect of high meat intakes on health is for colorectal cancer.
- The World Health Organization’s International Agency for Research on Cancer (IARC) has classified processed meat as carcinogenic to humans because of an association with colorectal cancer, and red meat is classified as probably carcinogenic to humans.
- IARC estimates that 34,000 cancer deaths per year worldwide are attributable to diets high in processed meat.
- Livestock production is responsible for ~15% of all anthropogenic emissions.
- Using the composite measure of CO2 equivalents (CO2e), livestock production is responsible for ~15% of all anthropogenic emissions.
- About 4% of all meat and 8% of beef are produced in grass-fed-only, extensive systems.
- Agriculture uses more freshwater than any other human activity, and nearly a third of this is required for livestock.
- The average global consumption of all meat has been estimated to be 122 g day-1.
- Using food balance sheet data, the average global consumption of all meat has been estimated to be 122 g day-1, of which a third each is pork and poultry, a fifth is beef, and the remainder from sheep, goats, and other animals.
- The 2010 global average per capita consumption of 42 g day-1 unprocessed red meat and 14 g day-1 processed meat.
- A major review by the Food and Agriculture Organization (FAO) of the United Nations (16), which makes extensive use of expert judgement, projects an increase of 76% in the total quantity of meat consumed by mid-century.
- The value of livestock (globally and by region) as a proportion of total agricultural value in 2014: World: $887 B, Africa $53 B, Rest of Asia & South America $126 B, China $176 B, Europe $119 B, India $69 B, North America $185 B.
- Growth of soya exports (tonnes) for livestock from South America to China.
Other Important Findings
- Meat consumption has substantial effects on people’s health, and livestock production can have major negative effects on the environment.
- The consumption of different types of meat and meat products has substantial effects on people’s health.
- The strongest evidence of a specific adverse effect is the increased risk of colorectal cancer with high intakes of processed meat.
- Meat produces more emissions per unit of energy compared with that of plant-based foods.
- Meat production can be an important source of nitrogen, phosphorus, and other pollutants and affects biodiversity.
- Governments act to shape food systems for economic purposes and to protect health from contaminated food.
- If we are to shape consumer demand, more evidence is needed about the effectiveness of different interventions to influence food selection.
- Meat is a good source of energy and some essential nutrients.
- In high-income Western countries, large prospective studies and meta-analyses generally show that total mortality rates are modestly higher in participants who have high intakes of red and processed meat.
- Meat consumption at the population level can be estimated by using self-reported dietary surveys.
- The main approach to estimating the impacts of meat consumption on long-term health is through prospective epidemiological cohort studies.
- Meat is a good source of energy and a range of essential nutrients, including protein and micronutrients.
- The main approach to estimating the impacts of meat consumption on long-term health is through prospective epidemiological cohort studies.
- Meat production results in the emissions of all three and is the single most important source of methane (51, 53).
- Agriculture uses more freshwater than any other human activity, and nearly a third of this is required for livestock (Fig. 4A) (61).
- A recent meta-analysis reported that high intakes of processed meat (but not unprocessed red meat) are associated with a moderate increase in the risk for mortality from cardiovascular disease.
- Various national and international bodies recommend an upper limit of meat consumption for maintaining good health.
- In many developing countries, the understandable pressures from poor people needing to produce food lead to a vicious circle of unsustainable overgrazing and an increasing demand for grazing land.
Limitations Noted in the Document
- The results of epidemiological studies have to be interpreted with great care so as to allow for potential confounding factors.
- Randomized controlled trials in humans are extremely difficult to conduct, especially over more than a few weeks or months.
- In high-income Western countries, a lower meat intake may be a marker of a health-conscious lifestyle.
- In low-income countries, lower meat intakes are more likely to be markers of poverty and associated with other risk factors for poor health.
- The information needed to remove statistically the influence of these confounding factors may not be available.
- There is considerable variation in water footprint among types of meat and production systems.
- Studies of how people justify to themselves the consumption of meat show that belief that it is “natural, normal, necessary, or nice” explains the large majority of variance in consumption (73).
- It is difficult to envisage how the world could supply a population of 10 billion or more people with the quantity of meat currently consumed in most high-income countries without substantial negative effects on environmental sustainability.
- Currently, various national and international bodies recommend an upper limit of meat consumption for maintaining good health.
Conclusion
The review underscores the significant environmental and health consequences associated with rising global meat consumption, emphasizing the need for comprehensive and multifaceted interventions. The authors highlight the substantial effects of different types of meat and meat products on human health, with a strong emphasis on the increased risk of colorectal cancer from processed meat consumption. The negative impacts of livestock production on the environment, including greenhouse gas emissions, water usage, and land degradation, are also central to the discussion. The review emphasizes the complexity of the food system, influenced by economic, cultural, and psychological factors, and the role of various stakeholders, such as governments and civil society organizations. The article underscores the necessity of understanding the interplay between conscious and nonconscious processes in food selection, acknowledging that interventions within a rational choice framework may not always be effective. The authors propose that interventions should target both the rational and the automatic processes, suggesting that changes in the food environment can influence purchasing and consumption behavior. However, the authors also acknowledge the difficulty of influencing consumer demand and highlight the need for more evidence on the effectiveness of interventions. They suggest that any successful interventions will require a deep understanding of the impact of meat consumption and a social license for governments and other bodies to implement change. Furthermore, they call for coordinated efforts across civil society, health organizations, and government to drive sustainable dietary behaviors. The history of dietary changes suggests that change in dietary behaviors in response to interventions is slow. The complexity of the food system, the existence of vested interests, and the power dynamics involved make the political economy of diet change highly challenging. The review’s conclusion emphasizes that effective strategies to address the environmental and health challenges of meat consumption require a combination of scientific understanding, policy interventions, and societal engagement, to achieve sustainable food systems.