This is because, despite the world population more than doubling since 1950, crop production has more than trebled over the same period. This means that we now produce over 40 per cent more food per capita than we did in the 1950s.

Such a magnificent and often-forgotten achievement in feeding the world is largely thanks to science-based advances in crop breeding and management, of which the most notable was the Green Revolution in the 1960s and 1970s that averted almost certain famine in large areas of Asia. Today, we produce more than enough food to enable each and every person on the planet to have an adequate and nutritious diet.

Even if, as reliably forecast, the world population increases to nine billion by 2050, we could still easily feed everybody by reducing meat consumption and ensuring equal distribution of food to all. The resultant diet might be rather monotonous – a little like the 1940s wartime diet – but at least nobody would need to starve.

Of course, this will never happen. We live in a deeply unequal world where access to food is very patchy and depends on where you happen to be born. Food has always been an economic good and a powerful political/military tool. During the twentieth century, large-scale manmade famines that killed millions became sadly commonplace.

In the 1920s and 1930s, the Soviet authorities deliberately engineered famines that killed over 10million people. Massive famines on a similar scale were allowed to occur by neglect and poor management by the British in Bengal in 1943 (three million deaths) and by the Chinese in 1959-61 (causing somewhere between 14million and 26million deaths). More recently, it is estimated that five million people in the war-torn eastern Congo died from famine and disease between 1998 and 2004.

In all of these cases, plentiful food supplies were available elsewhere in the world, and often within the same country as the famine itself. But sufficient food was not distributed for a variety of reasons. In this sense, each of the famines can be regarded as manmade.

A more positive use of food in politics is to supply it as a form of aid, friendship, or even coercion between nations. One of the most perceptive appraisals of the potential power of food as a tool of realpolitik originated in late-nineteenth century America. There, thanks to a great deal of public and private investment in agricultural research and development, new crop varieties, new equipment and improved farm inputs were developed. As a result, wheat yields increased sevenfold between 1850 and 1900, while maize yields increased more than fourfold between the 1920s and 1990s.

This produced millions of tonnes of surplus grain that was available for export. Better transportation links opened new markets in America’s growing cities and across the Atlantic to an industrialising Europe. By the early 1900s, America had come of age as a global agricultural power. Throughout the twentieth century and beyond, the US government continued to use its status as the ‘bread basket of the world’ to favour allies (for example, feeding the British during both World Wars) and to punish foes (such as the 1980-81 grain embargo against the USSR), not to mention earning a very healthy profit from sales of the exported food.

In the 1980s, the US secretary of agriculture, Earl Butz, even referred explicitly to what he called the ‘food weapon’. Today, the US is still able to maintain a vast, highly efficient, but highly publicly subsidised food production system that produces huge surpluses either for sale or as carefully targeted ‘aid’ overseas.

One of the most serious sources of food inequality and most effective barriers to agricultural innovation in many poorer countries is the current system of subsidies and trade tariffs that favour more powerful regions such as Europe, North America and Japan. The latter regions subsidise relatively inefficient domestic production of dozens of crops including rice (Japan), sugar beet (Europe), maize for bioethanol (USA), and rapeseed for biodiesel (Germany) in a way that distorts global trade and discriminates against more efficient crops such as tropical rice, sugar cane, and oil palm.

The overall effect is to depress the agricultural sectors in many developing countries so that they fail to create strong institutions able to improve their own crops and feed their populations. Despite decades of postcolonial development, endemic corruption and civil strife combine with poor infrastructure (including roads, schools, credit systems, legal systems and so on) to retard the inherent capacity of people in such countries for indigenous improvements in food production using a combination of the best of modern science with the more reliable and effective elements of traditional knowledge.

Rather than ‘sticking plaster’ responses, such as emergency food aid, the West should facilitate the genuine social and economic advancement of developing countries. We could start by dismantling inappropriate trade barriers, curtailing certain NGO activities that smack of neo-colonialism, and enable the farmers and breeders in these countries to develop production systems for their own benefit. 

We also live in a uniquely grotesque period of human history and achievement where increasing levels of malnutrition and even starvation coexist with record rates of morbid obesity. According to the UN Food and Agriculture Organisation (FAO), in 2006, the number of grossly overweight people in the world exceeded, for the first time, the number that is malnourished due to lack of food.

It is rather bizarre to reflect that in so-called ‘advanced’ Western countries, the obesity epidemic is concentrated in socio-economic groups of relatively low income and educational achievement. And, paradoxically, despite their excess food intake, obese people regularly manifest deficiency symptoms due to an unbalanced diet with inadequate intake of vitamins and other key nutrients.

Therefore, much of the ‘surplus’ food production of the world, the diversion of which keeps one billion people in developing countries on the edge of starvation, is not used by rich people at all. Rather it is mostly consumed by poorer, ill-informed folk in Western countries who consequently become both overweight and badly nourished, and are much less likely to be economically active. Such people also experience dramatically reduced life expectancies, and then tend to pass on their obesity (both biologically and culturally) to their unfortunate children.

Therefore, the much proclaimed end of the era of cheap food in the West may actually turn out to be a good thing for the world as a whole. We should question whether we really need the vast and wasteful supermarket/warehouses with their tens of thousands of items of rapidly spoiling food, of which between one third and one half is thrown out either by the retailer or by careless shoppers who buy too much for their needs. If we valued food more, we would be less likely to waste it and perhaps less likely to eat too much.

We would also be able to pay food producers more, both locally and in developing countries, although this may need a reduction in the stranglehold exerted on the supply chain by global supermarket networks. A willingness to pay more for food would also take the political pressure off governments to maintain the pernicious system of trade barriers and subsidies. Dismantling the latter would greatly stimulate food production in many developing countries and help them feed themselves in the future. 

Denis Murphy is biotechnology advisor to the United Nations Food and Agriculture Organization. He is also professor of biotechnology at the University of Glamorgan in Wales where he lectures on agriculture, botany and human nutrition.