November 21, 2022, by Lexi Earl

How do we feed the world in the face of global population growth, changing demographics and climate change?

This post is written by Prof Andy Salter

While the implications of, and solutions to, climate change, were discussed at COP27, two major global demographic landmarks were reached. The global population reached 8 billion and the population of India now matches that of China. These figures highlight the multifactorial challenges we face in ensuring adequate nutrition for the world. While China and India may have similar sized populations, as a result of both economic and cultural differences, major differences exist in the nature of their diets. This is illustrated by the major sources of dietary protein, which are shown in Figure 1 compared to some other regions of the world.

In recent decades, China has followed the pattern of richer countries and dramatically increased its consumption of meat (particularly pork), which represents a rich source of high quality proteins (containing appropriate amounts of, highly digestible, essential amino acids) and a range of micronutrients including iron, zinc, vitamin B12 and vitamin D. This, however, comes at significant cost to the environment, with vast amounts of land, and fresh water required to produce crops to be used as animal feed. Diets rich in red meat are also associated with increased risk of non-communicable diseases such as cardiovascular disease, colon cancer and possibly, type 2 diabetes. By contrast, driven by both economics and strong cultural avoidance of meat, India is largely dependent on plant sources of protein, and average intakes are similar to those of the continent of Africa. While requirements can generally be met by consumption of a range of plant sources, in India the large dependence on cereal crops means that many individuals are at risk of essential amino acid deficiency. A recent report by Right to Protein highlighted the fact that 84% of Indian vegetarian and 65% of non-vegetarian diets are protein deficient. Even amongst ‘urban rich’ Indians, 73% are protein deficient. The report highlights the need to better educate the population about the importance of adequate protein intakes and calls upon government and industry to work together to make more sources of plant-based (particularly pulses) and animal-based protein more affordable and accessible in India.

But what does the future hold? In August, the United Nations issued their updated predictions for global population changes and, as can be seen in Figure 2, these vary dramatically across the world.

While the populations of India, the UK and the USA are all set to remain relatively stable, China will see almost a 50% decline. While this may be seen as potentially a good thing, in terms of the impact of food production on the environment, it should also be noted the demographics of the Chinese population (and that of most ‘high-income’ countries) is also set to change dramatically. In China the number of elderly (65y and over) is set to increase from a current level of 14% to over 40%. The combination of declining numbers, and increasing age of the population brings into question whether they will be able to maintain an appropriate workforce in food production, and suggests that they may become increasingly dependent on imports. However, potentially eclipsing such changes is the predicted increase in the population of sub-Saharan Africa which will double by 2050 and triple by the end of the century (reaching approximately 3.5 billion). This population increase will be occurring in a region of the world which is already suffering from high levels of malnutrition. In terms of protein, the population are again highly dependent on cereal crops which, in a recent publication looking at Malawi, we have shown makes people particularly susceptible to amino acid deficiencies.

So how will this region cope with such a dramatic increase in population? Obviously, the worst-case scenario would be continued, and increasing, susceptibility to malnutrition, which may be further confounded by the impact of climate change on the production of traditional crops. This could be, at least partly, offset by increased production and consumption of livestock. However, this is likely to be unsustainable, with ever-increasing effects on global warming (including effects of increased methane production) and increasing demand on land and water resources to produce animal feed. Perhaps the best outcome would be a diversification of food sources, particularly those which are protein–rich. Such a shift is already being seen in more high-income regions as we attempt to move away from such a high dependence on animal derived foods. As we have recently reviewed, a range of alternative protein sources, including alternative crops, insects, single cell organisms and even cultured meat, are emerging as viable alternatives as either human foods or animal feed ingredients. However, as these emerging industries battle to try and ensure these represent healthy, sustainable and affordable alternatives for Western economies, it would be a further step-change to see many of them emerge as realistic alternatives in poorer regions. However, the clock is ticking and there is an urgent need for us to work with poorer regions, in the face of dramatically changing demographics, to ensure we can produce sufficient food to maintain a healthy population and a healthy planet. The question is, in these turbulent times, do we have the appetite for it?

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