Review: Trends for meat, milk and egg consumption for the next decades and the role played by livestock systems in the global production of proteins.

Meeting the food demands of a growing global population within planetary boundaries is a challenge. Sustainably producing animal-sourced foods while supplying sufficient protein to meet the requirements of a healthy diet is a particular challenge. This paper informs the development of pathways to sustainable animal production by examining trends in animal-sourced foods since 2000, including the significance of animal- relative to plant-protein sources. Drawing on three distinct scenarios defined by the Food and Agriculture Organization (FAO), (i.e. Business As Usual (BAU), a continuation of historical trends of food preferences including initiatives to address Sustainable Development Goal targets; Stratified Societies (SSs), leaving challenges unattended; and Towards Sustainability (TS); a more equitable global society and more sustainable food system due to effective polices), future demand for animal-sourced foods is projected. Analysis is based on FAO Food Balance Sheet data (2000-2017) and projected national protein demand per capita (2012-2050). Analysis is disaggregated to five global regions defined by the World Health Organization. It finds that patterns of past demand for animal-sourced foods vary by food (e.g. red vs white meat) and region. However, the European region consistently has the highest levels of consumption of animal-sourced foods, while the South-East Asian and African regions have the lowest. The ratio of animal to plant-sourced protein varies across regions, ranging from 0.29 in Africa to 1.08 in Europe in 2017. Over time, the ratio is relatively stable or moderately increasing, driven by rising incomes in low- or middle-income countries. Under the future scenarios, all World Health Organization regions show a marked increase in demand for animal-sourced protein across BAU and SS. The TS scenario, however, projects notable declines in consumption across Europe and the Americas when compared to the 2012 BAU baseline, with a decline in milk also in the Western Pacific. In contrast, meat and milk consumption in Africa and South-East Asia is projected to increase, reflecting their far lower starting consumption levels. The analysis and subsequent discussion highlight the importance of having regional-specific strategies to deal with the challenge of sustainable livestock production and consumption, with a requirement to consider the impact of actions in one region on others. Clearly, the challenge is not merely one for science and technology but one based on wider aspects of the food system and its diverse stakeholders.