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Chewing the fat

Global meat consumption is rising annually as the human population grows and affluence increases. Sterling Crew examines the environmental impact of this trend and looks at strategies for addressing sustainability in food consumption and agriculture.

Meat consumption

Paleontological evidence indicates that meat constituted a substantial proportion of the diet of even the earliest humans and that we have hunted and killed animals for meat since prehistoric times. With civilisation came the domestication of animals, which eventually led to the use of livestock in meat production on an industrial scale.

Across Britain, an increasing number of consumers have become vegans, vegetarians and flexitarians and others are just eating less meat.

Dietary choices

The amount of meat in our diet differs significantly amongst individuals, across cultures and worldwide. Meat is a good source of energy and some essential nutrients, including protein, essential amino acids and micronutrients, such as iron, zinc, selenium, riboflavin and vitamin B12. It is however possible to obtain a sufficient intake of these nutrients without eating meat if a wide variety of other foods is consumed. The NHS advises that with good planning and understanding of what makes up a healthy, balanced vegan diet, it should be possible to obtain all the essential nutrients without consuming meat, dairy or eggs[1].

Across Britain, an increasing number of consumers have become vegans, vegetarians and flexitarians and others are just eating less meat (Table 1). This is largely driven by concerns about health, animal welfare, ethics, religious dietary laws and environmental impact. Research conducted in 2016 by the Vegan Society estimated that there were around 540,000 vegans in Great Britain – 3.6 times as many as there were in 2006[2]. People are spending more money on vegan products and plant based diets are trending online. In January 2018, more than 168,000 people pledged to go vegan under the Veganuary campaign. The variety and quality of food choices to flexitarians, vegetarians and vegans in the UK has improved dramatically in recent years. The appeal of vegetarian and vegan products shows no sign of declining and after a recent dip, the retail market is now expected to grow to £658m by 2021[3].

Most people living outside the Western economies already tend to eat more plant based diets for reasons of economy because they simply cannot afford to eat meat. However, global meat production has increased rapidly over the past 50 years with total production having grown 4-5 fold since 1961[4]. One third of the average global consumption of meat is pork, a third is poultry, a fifth is beef and the remainder is from sheep, goats and other animals.

This increased meat consumption is due to the rise of the middle classes in emerging economies, such as China and East Asia. For a large proportion of the global population, the price of meat today relative to their average income is now less than it has ever been. This brings with it a steady increase in meat consumption where once more sustainable plant based diets were followed. India is not reflecting this trend – probably because of the long tradition of vegetarianism amongst its religious communities. A review by the United Nations FAO (Food and Agriculture Organisation), in 2012 projected an increase of 76% in the total quantity of meat produced by mid-century[5]. This shift is underscored by the current biomass of mammals on the planet, which is made up of 60% livestock, mostly cattle and pigs, 36% humans and 4% wild animals[6]. This is also true for wild and domesticated birds, for which the biomass of domesticated poultry (dominated by chickens) is about threefold higher than that of wild birds. By 2050 there will be an extra two billion mouths to feed and increasing consumption of animal products will bring new challenges to global agriculture.

Table 1 Types of plant based dietary patterns

Environmental impact

According to the FAO report Livestock’s Long Shadow[7], meat production is one of the most important ways in which humans affect the environment. It assessed the full impact of livestock on environmental problems along with potential technical and policy approaches to mitigation and concluded that meat products are one of the largest contributors to greenhouse gases, air and water pollution, land degradation, energy and water use, deforestation and loss of biodiversity.

Feeding grain to livestock to produce meat, instead of feeding it directly to humans, involves a large energy loss making animal agriculture more resource intensive than other forms of food production. This is because meat produces more emissions per unit of energy compared to plant based foods, due to energy loss at each trophic level. Livestock production accounts for 70% of all agricultural land and 30% of the land surface of the planet[7]. It is estimated that the amount of water required for a meat diet is twice as much as that needed for a vegetarian diet.

A plant based diet cuts the use of land by 76% and halves the greenhouse gases and other sources of pollution that are caused by food production. The FAO report[8] concludes that livestock is responsible for 18% of greenhouse gas emissions. It reflects the growing consensus amongst the scientific community that meat production is extremely resource intensive and that dietary change towards plant based eating habits could significantly reduce agricultural land loading. It is evident that urgent action is required to address the current state of affairs.

“Meat products are one of the largest contributors to greenhouse gases, air and water pollution, land degradation, energy and water use, deforestation and loss of biodiversity.

Recent developments

October 2018 saw the publication of two important environmental impact reports, both of which generated global media attention. The first was the influential Intergovernmental Panel on Climate Change (IPCC) report ‘Global Warming of 1.5°C – a special report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty[9]. The 1.5 °C target was set by the United Nations Framework Convention on Climate Change Paris Agreement of 2015[10]. The report concludes that rapid changes must take place in four key parts of society: energy generation, land use, cities and industry. It highlights the contribution made by agricultural practices and dietary choices and comments that, while current trends are in the opposite direction, eating less meat and dairy is important.

The second report was published on the 10th October 2018 in Nature entitled ‘Options for keeping the food system within environmental limits[11]. The report concludes that the food system has a number of significant environmental impacts, including being a major driver of climate change, depleting freshwater and creating pollution through excessive use of nitrogen and phosphorus. Using a global food systems model, the study found that between 2010 and 2050 the environmental effects of the food system could increase by 50-90% reaching levels that are beyond the global boundaries that define a safe operating space for humanity, unless technological changes or dedicated mitigation measures are introduced.

The authors analysed the options for reducing the environmental effects of the food system, including dietary changes towards healthier and more plant based diets, improvements in technology and management and reductions in food waste, and found that no single measure was enough to keep these effects within the global boundaries. They recommended a synergistic combination of measures to address environmental impacts, including a flexitarian diet to halve emissions from livestock. This would mean the average person needs to eat 75% less beef, 90% less pork and half the number of eggs, while tripling consumption of beans and pulses and quadrupling nuts and seeds. The authors concluded that animal products usually require a more intensive and environmentally damaging mode of production than that needed for plant based food. The study also found that halving the amount of food lost to waste would reduce the environmental impacts of agriculture by 16%.

The challenge

Clearly, a significant reduction in meat consumption is necessary to help to mitigate climate change. However, the issue of eating less meat is very complex. The trade in livestock and related food products is a significant component of the economies of many rural communities and countries. Livestock and its associated processing industries provide employment for large numbers of people. Eating meat is a pleasurable experience for consumers and it is an important source of nutrients. Meat consumption has strong embedded personal and cultural associations. It often has symbolic meaning and important social functions. Food choices are by their very nature personal and behavioral and dietary change can be difficult to achieve.

Some cultures live in environments where meat is the only available sustainable food resource, for example the Inuit people of the Arctic. There is also a risk that people, especially the young and old, would suffer from a greater number of deficiencies in essential nutrients. There is even an argument that millions of undernourished people in poor nations need to eat more meat and dairy foods. There is still a lot of controversy over the data concerning the effects of livestock on the environment and its interpretation, depending on the vested interests.

Food science may well help to contribute a technological solution. Plant based meat substitutes could be one of the planet’s most critical future food technologies. Producing a palatably acceptable meat alternative for consumers would not only reduce environmental degradation but also contribute to improving health and making food more affordable. This is the food scientist’s Holy Grail. An example of this type of innovative alternative meat technology is Quorn. Launched in 1985, Quorn is made from mycoprotein from the soil mould Fusarium venenatum strain PTA-2684, which is grown by fermentation. It is sold as an ingredient and as a meat substitute in meals.

If the retreat from meat is to be encouraged, there needs to be an understanding of the socioeconomic and environmental factors at play to nudge a dietary change. It is encouraging that there is evidence for this working in some of the richer developed countries, where numbers of citizens choosing vegetarian and vegan diets are increasing. We already have a legal requirement under a European Directive to label all appliances with energy efficiency and this could be extended by using environmental labelling on foods to nudge behaviour in the same way as nutritional indicators are currently used. This could incentivise food businesses to act more sustainably, enable the consumer to make more informed choices on sustainable eating and encourage improved policymaking.

A recent study undertaken by scientists at the University of Oxford has calculated that in 2020 there will be 2.4m deaths attributable to red and processed meat consumption, as well as $285bn in costs related to healthcare[12, 13]. They found that red meat would need to be 20% more expensive and processed meat, such as bacon, sausages and jerky, would need to be more than double its current price to account for these health costs. The research suggests that if the optimum health taxes were introduced, the consumption of processed meat would decline by about two portions per week in high-income countries and by 16% globally.

Taxing food in this way raises obvious questions over its political acceptability and its effectiveness. Taxing plastic carrier bags has seen a significant reduction in their use. Public health taxation has been applied successfully to help reduce the consumption of alcohol and tobacco smoking. The fuel levy has been used as an ecotax to promote ecological sustainability. Taxes on transportation have been shown to be an effective tool to reduce pollution, conserve energy and help reduce global warming. The jury is still out on the sugar tax on soft drinks, although it has encouraged manufacturers to reformulate food products to reduce sugar content.

In 2020 there will be 2.4m deaths attributable to red and processed meat consumption, as well as $285b in costs related to healthcare.


Dietary change could play a significant role as part of a strategy to ensure future food security for a growing world population while mitigating environmental challenges associated with agricultural production. Even modest reductions in meat consumption in industrialised societies would substantially reduce the burden on natural resources and help to contain the environmental impacts of agriculture.

In November 2017, over 15,000 scientists signed a warning letter to humanity calling for a drastic reduction in per capita meat consumption. If the world wants to limit climate change, water scarcity and pollution, then we all need to embrace diets containing less meat. The current global growing demand for meat is simply unsustainable. Strategies for sustainability must address dietary change to ensure food security for future populations, while addressing the environmental challenges associated with agricultural production. We are the first generation to know that we are damaging our planet by increasing meat consumption and maybe the last that can do anything about it.

Sterling Crew FIFST, FCIEH, FRSPH CEnvH.

Chair of the IFST Food Safety SIG. Managing Director SQS Ltd. Strategic Advisor to Shield Safety Group and Dynamic Risk Indicator. Independent Scientific Advisor and Board Member of Campden BRI.









7. Food and Agriculture Organization of the United Nations. The Future of Food and Agriculture: Alternative Pathways to 2050 (FAO, 2018). Livestock's Long Shadow.Food and Agriculture Organization of the United Nations. Henning Steinfeld, et al., 2006. ISBN 92-5-10557-8.


9. Intergovernmental Panel on Climate Change. Global Warming of 1.5 °C (IPCC, 2018).

10. United Nations. Transforming our World: The 2030 Agenda for Sustainable Development (UN, 2015).

11. Springmann, M. et al., Nature 562, 519-525 (2018).



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