Food Supply and Population

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The relationship between a population and its food supply is a matter of prime importance. Awareness of this is reflected, for example, in the Chinese characters corresponding to the English word population: 人 口. In these characters, a human figure appears on the left; an open mouth–requiring food–is on the right. However, it was economist T. R. Malthus's socalled "First Essay" of 1798 that famously portrayed the relationship in its starkest form. If unchecked, wrote Malthus, a population could grow geometrically, but given a limited area of cropland its food supply could grow only arithmetically, at best. These arguments raised the specter of "gigantic inevitable famine," which by raising the death rate would be the ultimate factor in restoring a rough balance between the population's size and its food supply.

Population and Food Supply–Recent History

Concern that population growth might outstrip the capacity to raise food production has been expressed many times since Malthus–particularly during the period from 1950 to 2000, when the world's population increased from about 2.5 billion to 6 billion. Writers like Paul Ehrlich and Lester Brown doubt whether food output can be raised to match this demographic growth. They see a future of mounting food supply difficulties, increasing hunger, and famines. However, the global death toll from famines has fallen very considerably since the mid-twentieth century. And while acknowledging that the world food situation and outlook have many problems, most analysts, including Nikos Alexandratos in 1995; Tim Dyson in 1996; Donald Mitchell, Merlinda Ingco and Ronald Duncan in 1997; and Alex McCalla and Cesar Revoredo in 2001, take a significantly more positive view.

The relationship between food supply and population is complex. There is no doubt that average levels of per capita food availability for the world as a whole have increased appreciably during recent decades. Thus the United Nations Food and Agricultural Organization (FAO) estimates that between the period from 1969 to 1971 and the period from 1997 to 1999 the average daily global level of per capita calorie (i.e. food energy) supply rose from 2,413 to 2,802 calories, and the daily availability of protein increased from about 65 to 75 grams per person (calorie and protein figures cited are from FAO, 2002). However, most of the world's population growth during this period happened in poor regions, like South Asia and sub-Saharan Africa, where it is estimated that sizeable fractions of the populations are undernourished (i.e. having levels of food consumption below those required to maintain body weight and support light activity). Consequently, FAO estimates that the total number of undernourished people in the world declined only modestly in the same period: from around 941 million to about 826 million, according to Alexandratos in 1995 and FAO in 2000.

East Asia–Positive Developments

At a broad regional level progress has been very variable. The most positive developments have occurred in East Asia. In China the period since 1980 has seen major gains in average per capita calorie supplies and protein intake, and the diet has generally become better and more diverse. Per capita incomes have risen, and with increased incentives to invest and increase their production, farmers have sharply increased their output of most foodstuffs–notably rice, wheat, fruits, vegetables, and pork. However, because there is little new land that can be brought into cultivation, almost all of this increase in food production has come about through processes of agricultural intensification: the improvements in food supply that China's growing population have enjoyed have occurred mostly through increasing food crop yields (i.e. output per unit of harvested area). China has invested heavily in crop research–especially in developing higher yielding varieties of rice–and Chinese farmers have also sharply raised their use of chemical fertilizers.

Southeast Asia, the Middle East, and Latin America–Mixed Results

In Southeast Asia, the Middle East, and Latin America there have also been significant gains in average levels of per capita food availability during recent decades–despite the occurrence of considerable population growth. Diets have generally become more varied, and the populations of these regions have experienced marked rises in their average supplies of calories and protein–again, mainly due to increased food crop yields. The technological developments arising from the so-called Green Revolution starting in the late 1960s–especially the introduction of higher-yielding varieties of rice and wheat, combined with greater applications of nitrogenous fertilizers on irrigated land–have benefited most countries.

However, in the Middle East, where water for agriculture is often in short supply, many countries have also turned to purchasing sizeable quantities of cereals on the international market–much of which is then used as livestock feed in order to produce meat. Indeed, some Middle Eastern countries rely upon cereal imports for as much as half of all the grain they use. This is a notable case in which increased trade has augmented food supplies in the face of a significant environmental constraint (i.e. water scarcity) and substantial demographic growth.

Conditions for food production are generally favorable in Latin America, where some countries, notably Brazil and Argentina, are major exporters of products like fruits, vegetables, wheat, and meat. Of course, the positive food situation in these three regions should not obscure the fact of considerable inter-country variation. Cambodia, Peru, and Sudan, for example, have populations with very low per capita supplies of calories and protein. And, as in East Asia, there are significant numbers of poor, undernourished people in each of these regions.

South Asia–Significant Problems

The food situation in South Asia is significantly worse than in the regions discussed above. The FAO estimates that India alone contains about one quarter of all the world's undernourished people; in the years 1996 to 1998 its average calorie supply was estimated at only 2,434 per person per day. A particular problem of the South Asian diet is its lack of high quality protein due, in part, to widespread vegetarianism. It is uncertain whether the nutritional content of the Indian diet has improved much during recent decades, despite significant increases in average incomes and little change in the real price of food. What has happened is that people have diversified the foods they consume, purchasing more fruits, vegetables, and milk, but reducing their consumption of legumes, which are nutritionally rather valuable. Food production in South Asia has benefited from high-yielding varieties of wheat and rice, but there has been little change in the cultivation of traditional coarse cereals. Consequently, the per capita availability of these latter food crops, which tend to be more nutritious, has fallen.

The nutritional status of South Asia's population is generally dismal. In India, for example, nearly half of all children under age three are estimated to be underweight, and a similar proportion of adult women are anemic. However, such health and nutritional problems are often not seen as problematic by the people themselves: Virtually all Indian households report that they have "two square meals a day." With an increasing variety of non-food items available for purchase in local markets, increased per capita incomes have often not been spent on food.

South Asia's population could well increase by 600 million in the first half of the twenty-first century. Average levels of food consumption may well rise, but this demographic growth, and recent trends in food demand and production, do not augur well for a major decrease in the total number of under-nourished people.

Sub-Saharan Africa–Widespread Undernourishment, Grim Prognosis

In major world regions the food situation is probably grimmest in sub-Saharan Africa, where FAO (2000) estimates that in the period from 1996 to 1998 about one-third of the total population was undernourished. The region's estimated per capita daily calorie supply for the years 1997 to 1999 suggests scant improvement compared to the 1969 to 1971 period. This is the world's poorest region and it has experienced the fastest demographic growth, with populations often doubling in less than 25 years.

African farmers have been unable to raise their food crop yields at similar rates. In fact, average cereal yields rose very little in the decades around the turn of the century. Consequently, total food output has been increased largely through processes of extensification–increasing the harvested area. Traditional fallow periods have been reduced (often leading to losses in soil fertility) and the area of cropland has been increased by converting tracts of bushland and forest to cultivation. These developments have sometimes occurred in conditions of sociopolitical instability, and where governments have neglected the agricultural sector. Moreover, until the early 1990s global agricultural research tended to be focused on crops like rice and wheat, which are not widely grown in sub-Saharan Africa. There is no doubt that given appropriate levels of investment this region's agricultural potential is considerable. But most analysts envisage that in the first decades of the twenty-first century average levels of per capita food production and consumption will not rise by much. With the likelihood of considerable future population growth the total number of undernourished people may well increase. Adding to this bleak outlook, the region may continue to experience food crises and famines–often with warfare acting as an important contributory cause.

The Developed World–Obesity, Overproduction, Farm Subsidies

In considering the world's more developed regions, the situation is clearly very different. In most developed countries the number of people who are undernourished is tiny (although the economic disruption following the collapse of communism in Eastern Europe and the former Soviet Union in the 1990s caused real hunger at times). However, in the developed world obesity–linked to overeating and sedentary lifestyles–is often a serious and growing problem (one, it must be said, which is also increasing in many urban areas of the developing world).

Recent decades have seen considerable competition in the agricultural sector, particularly between the United States and the European Union. Both these major food-producing blocs have experienced difficulties in trying to reduce the subsidies they pay their farmers, yet at the same time agricultural yields have continued to rise, often at a brisk pace. Consequently, the overproduction of food in relation to the volume of effective demand (the ability of people or nations to pay for it) has been, and continues to be, a serious problem. A consequence is that the prices of many foods, including important cereal crops like wheat and maize (i.e. corn), on the international market remain low. This benefits the developing countries that import these crops–for example, those in the Middle East. But these same low prices are harmful to agricultural producers and exporters in other countries, including some of the poorest developing countries. These problems of international political economy are the subject of negotiations


in the World Trade Organization, but they are unlikely to go away.

Summary–Progress and Problems

In summary, progress in feeding the growing world population has been mixed. For most regions the situation has improved; although even in China, where progress has been marked, there remain tens of millions of people who lack the purchasing power to buy sufficient quantities of food. The record of South Asia, however, is best described as patchy; and for sub-Saharan Africa it is bad. There is no doubt that the knowledge, crop varieties, and technologies to significantly raise per capita food supplies in these two regions exist. But the socioeconomic and political conditions for their successful utilization have often been lacking. Moreover, population growth in both regions has probably made the task of raising average levels of food availability per person harder than it would otherwise have been. This situation appears likely to continue into the early decades of the twenty-first century. There will be significant progress in raising average levels of food consumption in most regions, but with South Asia and, still more, sub-Saharan Africa lagging behind. In general, population growth in the developing world will continue to be the main factor contributing to the growth of world cereal demand; and some of this growth in demand will be met by increased production from farmers in more developed regions, especially in North America.

Cereals–Indicator of Diet Quality

This brief account of food and population can appropriately conclude with a comment on cereals, the most important component of the human diet. Cereals make up about half of all direct human caloric intake (as bread or cooked rice, for example), and perhaps two-thirds if account is taken of the large quantities of cereals that are fed to animals to produce meat, milk, and eggs. Cereal data can be used to exemplify the same basic element of identity between a population and its food supply that was illustrated by the Chinese characters for population described above. Figure 1 plots the relationship between the size of the world's population since the early 1950s and the average level of the world cereal yield. It reflects the fact that to a considerable extent the huge growth of the global population during recent decades has both contributed to, and been supported by, the rise in the average world cereal yield. Demographic growth has meant that yields have had to be increased, while at the same time the attainment of higher yields has supported the increasing population. Note that the relationship is fairly tight–sufficiently so to make a reasonably firm prediction that when the world's population reaches 8 billion, which it is projected to do around the year 2025, the world cereal yield will be slightly above four metric tons per hectare. Such a yield will be required to supply food for a world of 8 billion.

See also: Land Use; Natural Resources and Population; Nitrogen Cycle.


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internet resource.

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Tim Dyson