The Nutrition Transition

Evolution is transition. Fueled by ideas, war, scientific breakthroughs, and chance, the relationship of humans with their environment is in constant change, in an endless quest for equilibrium.

The Nutrition Transition

Data from the past decade and projections for the next 20 years (Murray and Lopez, 1996) indicate a continuing rise in the contribution of no communicable diseases to mortality rates in developing countries, where a large proportion of the global poor lives.

The Nutrition Transition

Robert W. Fogel and Lorens A. Helmchen, The growth in material wealth has been matched by changes in body size over the past 300 years, especially during the twentieth century.

The Nutrition Transition

Per capita availability of calories more than doubled in this period in France, and increased by about 50% in Great Britain, where caloric supply was 30% larger than that in France at the beginning of the period.

The Nutrition Transition

The role of genes in the human adaptation to rapid environmental changes has been postulated for many decades, but only with advances in molecular genetics can we identify with some clarity the interactions between genes and environmental components such as diet.

Jumat, 28 Oktober 2011

Malnutrition in the developing world & Future food needs

Malnutrition in the developing world
Food deficits, regardless of whether they are on national, local or individual level, or if they range from marginal to crippling, are rarely caused by absolute physical short-ages. Such cases arise repeatedly only as a result of protracted civil wars (recently in Afghanistan, Angola, Ethiopia, Mozambique, Somalia, and Sudan) and temporarily as an aftermath of major natural catastrophes. Chronic undernutrition and malnutri-tion result from inadequate individual or group access to food that is strongly related to social status and income. This conclusion is true for both the richest as well as the poorest countries.
FAO’s past estimates of the global share of undernourished people ranged from a clearly exaggerated fraction of two-thirds in the late 1940s (an overestimate caused largely by unrealistically high assumptions regarding average protein needs) to less than one-seventh in the early 1990s. The latest estimate, for the period between 1996 and 1998, adds up to 826 million undernourished people, or about 14% of the world’s population at that time (FAO, 2000). As expected, the total is highly unevenly split, with 34 million undernourished people in the developed and 792 million people in the developing world. The highest shares of undernourished population (about 70% of the total) are now in Afghanistan and Somalia, whereas the rates for India and China are, respectively, about 20% and just above 10%. These shares make India the country with the largest number of undernourished people (just over 200 million, or roughly a quarter of the world’s total, spread pretty much all around the country), whereas China’s aggregate (mostly in the northwestern and southwestern interior provinces) is about 140 million.
There are, of course, different degrees of undernutrition, ranging from mildly under- weight (with body mass index of 17–18.5) to severely underweight (with body mass index below 16; the normal healthy range is 18.5–25). The FAO (1996) also put the number of stunted children (with low height-for-age) at 215 million, underweight chil-dren (low weight-for-age) at 180 million, and wasted children (low weight-for-height) at 50 million. As there are many uncertainties regarding both the data and assumptions that go into the process of comparing food supplies and needs, all of these figures must be seen as informative estimates rather than as accurate totals. Nevertheless, there can be no doubt about the enormous human and socioeconomic toll of this nutritional dep-rivation. Perhaps the worst health impact arises from the well-documented effect of  undernutrition on early brain development (Brown and Pollitt, 1996).
Shortages of food energy and dietary protein are not the only causes of serious mal- nutrition as micronutrient deficiencies are even more common. Blindness caused by shortages of vitamin A is among the most cruel consequences of inadequate diets. The xerophthalmia syndrome includes night reversible blindness caused by lack of retinol in the eye’s retina, corneal ulceration and eventually irreversible loss of eyesight. In addition, low levels of vitamin are associated with higher mortality from respiratory and gastrointestinal diseases, and with their more severe course. FAO estimates that the total population at risk is well over half a billion, that there are about 40 million preschool children with vitamin A deficiency, and that perhaps half a million of them go blind annually (FAO, 1996).
Some micronutrient deficiencies have environmental origins. The World Health Organization estimated that 1.6 billion people, or more than a quarter of the world’s population, have some degree of iodine deficiency (WHO, 1993). Estimates of the total number of people with goiter, the condition almost always associated with some mental impairment, are as high as 600 million (Lamberg, 1993). WHO also credits iodine deficiencies during pregnancy with at least 25 million seriously brain-damaged children and nearly six millions cretins, whose severe mental retardation is combined with hearing loss or mutism and abnormal body movements. As for the economic impact, Arcand (2000) concluded that if the sub-Saharan countries with average dietary supply below the minimum requirement in 1960 had eliminated hunger by raising the average per capita food availability to nearly 2800 kcal/day (i.e., essentially China’s current mean) their per capita GDP in 1990 could have been as much as $3500 rather than the actual $800.
Future food needs
Three key factors will drive future demand for food. By far the most important is the continuing population growth throughout the developing world. Second, is the all too obvious need to close the gap between today’s inadequate food intakes that have to be endured by some 800 million people throughout the poor world and the minima com-patible with healthy and productive lives. The third factor is the further improvement of the quality of diets in poor countries (given the great existing food surplus, getting rid of nutritional inadequacies throughout the rich world should not call for any increases in production). At least three principal factors will determine the eventual outcome: the level of agricultural investment and research; the extent and tempo of dietary transitions, particularly the higher consumption of animal food in today’s developing countries; the success in making future food production more compatible with biospheric limits and services; and the fate of genetic engineering.

Jumat, 21 Oktober 2011

Population growth

After decades of accelerating growth the global rate of population increase peaked at just over 2% a year during the late 1960s, and gradual declines of fertilities also speeded up the arrival of the absolute peak, at about 86 million people a year, during the latter half of the 1980s and the annual increase was down to 77 million people by the year 2000 (UN, 1998, 2001). As a result population projections issued during the 1990s had repeatedly lowered the long-term global forecasts for the next 50 years. The medium version of the 1998 revision envisaged just 8.9 billion people by the year 2050, down from 9.4 billion forecast in 1996, and 9.8 billion in the 1994 revisions (UN, 1998). And the high variant in 1998 was well below 12 billion people by the year 2050, in line with increasing indications that yet another doubling of human population to 12 billion people is unlikely (Lutzet al., 2001).
11                                                                                                 High
10                                                                                                 Medium
8                                                                                                   Low
1950 2000 2050
Figure 3.5
The UN’s latest long-term projections of global population growth (UN, 2001).

But the latest UN (2001) projection raised its medium 2050 forecast to 9.3 billion (Fig. 3.5). The difference of some 400 million people above the 1998 forecast is explained largely by the assumption of somewhat higher fertilities for the 16 develop-ing countries whose fertility has not, so far, shown any sustained decline. There is a different kind of uncertainty concerning the rich world’s population. Without substan-tial immigration it would start declining as a whole within a few years and by the year 2050 it would be barely above one billion, 20% below its current total (as already noted, UNO’s and FAO’s definitions of developed and developing populations are not identical: they differ by about 100 million people). With continued immigration it would be more or less stable, reaching 1.8 billion in 50 years. Even then many European nations and Japan would experience substantial population declines. Russia’s case is particularly noteworthy, as it now appears that there is little chance of revers-ing its population decline brought on by economic deprivation, social disintegration and exceptionally high rates of alcoholism. As a result, Russia may have 30 million fewer people by the year 2050. By that time the US population will, most likely, approach 340 million.
Inherent uncertainties of long-range forecasting aside, there is no doubt that virtu-ally all the net population increase of the next two generations will take place in today’s developing world, and that the global population of 2050 will, most likely, be 50% larger than it is today. Moreover, most of the additional population growth of some 2.8–3.2 billion people will be concentrated in nations whose agricultural resources, although absolutely large, are already relatively limited. Brazil is the only modernizing populous country (i.e., with more than 100 million people) with abundant reserves of arable land and water (Fig. 3.6). Fifty years from now India, after adding nearly 600 million people, would have a population more than 50% larger than today and would be, with just over 1.5 billion, the world’s most populous country, with China a very close second. Three African and two Asian countries would add more than 100 million people each: Nigeria, Pakistan, Indonesia, Congo, and Ethiopia. As a group these nations would have to increase their food harvests by two-thirds merely to maintain their existing, and in many respects inadequate, diets.
0.3                         Brazil
            Bangladesh China
0 200 400 600 800 1000 1200
Population (million)
Figure 3.6
Brazil and Nigeria are the only two developing countries with considerable reserves of potentially arable land; in all other populous modernizing countries future increases of food output will have to come from further intensification of cropping. Plotted from data in FAO (2001).

Only Congo and Nigeria have relatively low population density per hectare of cul-tivated farmland and large untapped agricultural potential. At the same time, the late 20th-century record of these two countries makes it hard to imagine that they will be the ones to mobilize their resources effectively and to evolve a civil society deter-mined to bring widespread economic advances. China and Indonesia are already the paragons of highly intensive cropping, and India and Pakistan are close behind. But, some poorly informed and sensationalized judgments notwithstanding (Brown, 1995), there is more hope for China’s farming than is the case with perhaps any other large populous country (Smil, 1995). As already noted, China has about 50% more farmland than has been officially acknowledged (which means that its actual average yields are substantially lower than reported) and it has many opportunities for increas- ing the productivity of its cropping (Smil, 1999c). India’s situation, though undoubt-edly highly challenging, appears to be more hopeful than the Indonesian or Pakistani prospect. As for Ethiopia, natural aridity affects large parts of its territory and already limits its food production capacity.

Jumat, 14 Oktober 2011

Increased demand for animal foods

As described in the previous section, af uence changed this consumption pattern but intakes of animal foods are badly skewed in favor of high-income populations. Industrialized nations, amounting to only a fifth of the global population total, now produce a third of hen’s eggs, two-fifths of all meat, and three-fifths of all poultry and cow’s milk. Animal foods now supply around 30% of all food energy in North America and Europe, around 20% in those East Asian countries that have reached apparent satiation levels (Japan, Taiwan) and far below 10% in the most food-deficient coun-tries of sub-Saharan Africa (FAO, 2001). This means, as already noted, that the daily food supply of rich nations now averages about 55g of meat and milk protein per capita, compared to just 20g in the developing world, and the actual gap is even larger for hundreds of millions of subsistence peasants and poor urbanites surviving on diets virtually devoid of any animal foods.
With meat and dairy intakes being up to an order of magnitude higher in af uent nations than in many poor countries this means that extending the current per capita supply means of developed countries (i.e., above 250 kg for milk and close to 80 kg for meat) to all of today’s low income countries (i.e., to 4.7 billion people), as well as to the additional three to four billion people that will be added in those countries dur-ing the next two generations, would call for an impossibly large expansion of feed production. The three important questions are then as follows. Should such a goal be seen as being at least theoretically desirable? What are the chances that developing countries would move as rapidly, and as far, toward the af uent (Western) consump-tion pattern as their limited resources will allow? And to what extent can we improve the prevailing feeding efficiencies?
Only the first question has an easy answer. There is no need to present a massive sur-vey of current nutritional understanding or to engage in polemics on behalf of, or against, vegetarianism, a nutritional choice that most people will not consider following voluntarily in any case, or high-level carnivory. What is abundantly clear is that humans do not need high levels of animal food intakes either to lead healthy and productive lives or to achieve average population longevities in excess of 70 years, and that no other known existential benefits are predicated on consuming at least as much meat and dairy products as the developed countries do today. Moreover, as recent experiences with some consequences of animal feeding and rearing have demonstrated (European mad cow disease and foot-and-mouth epizootic leading to large-scale slaughter of cattle and sheep, and Asian bird viruses resulting in mass killings of poultry) the scale and the very nature of meat-producing enterprises may actually be a threat to human health, or at least a costly inconvenience. In contrast to these fairly indisputable conclusions the pace and the extent of dietary transition is much harder to predict.

Jumat, 07 Oktober 2011

Dietary patterns

No other factor will determine the future demand for animal foods as much as the degree of westernization of diets in developing countries in general, and in populous Asian nations in particular. Informed discussion of this prospect must start by acknowledging the fact that, in spite of broad similarities, there are substantial differ-ences in meat and fat intakes among Western countries. This means that there is no generic Western diet to which the developing countries might aspire. Although all major indicators of quality of life are very similar for all of the af uent nations of Western Europe, per capita supplies of meat differ by about 40%: Norwegians get less than 60kg/year, French almost 100kg/year (FAO, 2001). And whereas Greeks con-sume less than 5 kg of butter and lard a year per capita, the Finnish mean is close to 15 kg. Such comparisons make it clear that the European pattern, although very similar in total energy and protein intakes, spans a range of distinct categories from the Mediterranean to the Scandinavian diets.
Taking such differences into account, Seckler and Rock (1995) suggested that two different patterns of food consumption should be considered when forecasting the future composition of food intakes in developing countries. They define what they call the Western model as the daily mean supply of more than 3200 kcal/capita with more than 30% of food energy coming from animal foodstuffs. But a great deal of evidence confirms that another model – what they label the Asian–Mediterranean pattern, with overall food energy availability below 3200 kcal/capita and with animal products sup-plying less than 25% of food energy – appears to be a more powerful attractor for many developing countries.
Food balance sheets of the last two generations show that animal food intakes in the economically most successful developing countries have not been moving rapidly toward the Western consumption pattern. Egypt and Turkey have basically the same proportion of meat in their typical diets as they had 30 years ago. Japanese meat intakes have stabilized at around 40kg, as did the Malaysian average. Official output statistics would appear to put China into a different category and forecasts based on these numbers see China as a gargantuan meat-eating nation, but a closer look shows that the country will not move rapidly toward the Western attractor. China’s official output statistics, and hence also FAO food balance sheets based on them, credit the country with per capita output of about 47 kg meat in 1999, but the China Statistical Yearbook puts actual per capita purchases of urban households at 25 kg (unchanged in a decade!) and the meat consumption of rural families at less than 17 kg, up from about 13 kg in 1990 (National Bureau of Statistics, 2000). This means that the eventual doubling of average nationwide per capita meat consumption would result in a rate only marginally higher than the current value claimed by official statistics.
Forecasts of China’s future meat consumption have also been affected by simplistically extrapolating Taiwan’s experience. The island’s very high average per capita meat intake (about 80 kg) is not only the highest in Asia, it is even higher than the British mean, and its very low direct cereal consumption (less than 110 kg) is below the OECD’s mean of some 130 kg (FAO, 2001). Moreover, differences of scale between the two countries (1.2 billion vs. some 20 million of people) and the still very limited purchasing power of most of China’s peasants are two other factors militating against a further rapid rise of China’s per capita meat consumption.
Finally, it must be noted that the total consumption of meat, although still slowly rising in the US, has been declining in Europe (for example, in Germany it is down by 15% since 1980), which means that the Western pattern is actually shifting gradu-ally toward the alternative attractor. Consequently, there is a fairly high probability that tomorrow’s developing world, although definitely demanding higher animal food intakes, will not look toward yesterday’s French, Dutch, or US example. Widespread assumptions that rising disposable incomes will be readily translated into rapidly, and virtually universally, rising demand for meat may not come to pass. Whatever its actual level may be, lower than anticipated demand for animal foods would be much easier to meet, especially once a concerted commitment is made to improve the efficiency of feeding as much as practicable. But whatever the pace and the extent of coming dietary changes may be, the increasing carnivory could have a much lower demand on agricultural resources and could also result in much reduced environmental impacts if we were to feed the animals much more efficiently.