Kamis, 03 November 2011

Food supply

The world’s recent edible crop harvests prorate to about 4700 kcal/day per capita, but nearly half of the cereal production, worth about 1700 kcal/day, is fed to animals, and postharvest crop losses amount to some 600 kcal/day (Smil, 2000). This leaves about 2400 kcal/day of plant food and with some 400 kcal/day from animal foods (including aquatic products) the average per capita availability adds up to roughly 2800 kcal/day, well above a generous estimate of average needs of 2200 kcal/capita. Similarly, the world’s mean daily protein supply of 75 g/capita is well above the needed minimum. An egalitarian global civilization would thus have no problems with adequate nutrition. Equitable distribution of available food among the planet’s more than 6 billion people would provide enough protein even if the global food harvests were to be some 10% lower than they are today.
 In the real world these adequate global means hide, as do other global averages, large inter- and intranational differences. All Western nations enjoy uniformly high per capita food availabilities averaging about 3200 kcal/day. Their mean per capita supply of dietary protein is about 100 g/day, including about 55 g from animal foods. No elaborate calculations are needed to conclude that the average per capita food supply is more than adequate in all af uent countries. Because the actual requirements of mostly sedentary populations are no more than 2000–2200 kcal/day it is no exaggeration to label the resulting food surpluses (at least 1000–1200 kcal/day and up to 1600 kcal/day) as obscene.
After all, even when leaving aside the large energy and protein losses in animal feeding, at least 30% of all food available at the retail level in Western societies is wasted! Average Western diets in general, and the North American one in particular, also contain excessive amount of lipids, which now supply 30–40% of all food energy compared to the average of less than 20% in developing countries and to shares below 15% in the poorest societies (FAO, 2001). Surfeits of food energy and lipids are the two key nutritional factors implicated in the increase of obesity and diabetes and in a high frequency of cardiovascular disease (see Chapters 9–11). Fortification of many foodstuffs (from our to juices) with vitamins and minerals and a fashionable use of dietary supplements (including recurrent megadose manias) by increasingly health-conscious segments of the aging population would suggest that there are very few micronutrient deficiencies. This is, unfortunately, not true as clinical and biochemical studies in the US show that intakes of calcium, iron, and zinc are not adequate in some groups (Pennington, 1996).
 Given the obviously high incidence of overweight and obesity it is not surprising that hunger and malnutrition in af uent nations have received so little attention, but their extent is far from negligible (Riches, 1997). Poppendieck’s (1997) estimates that 22–30 million Americans cannot afford to buy enough food to maintain good health have been questioned, but even the most conservative estimates acknowledge that 10–20 million poor Americans could not feed themselves adequately without assistance, and that far from all of them are actually receiving it. The coexistence of undernutrition and widespread obesity is thus one of the most peculiar features of America’s current nutritional situation.
Japan, which is highly dependent on food imports, is the only high-income country with per capita food supply below 3000kcal/day (the rate has been steady at about 2900 kcal/day for nearly two decades). Specific features of the country’s food con- sumption include the already noted world’s highest per capita intake of aquatic products, exceptionally high intakes of soybeans (eaten mostly as beancurd), and very low con-sumption of sugar. Average food availability in China is now almost as high as in Japan (close to 2800kcal/day), but in spite of impressive post-1980 diversification (Fig. 3.4) its variety and quality is still much lower. Moreover, unlike in a highly egalitarian Japan, China’s mean hides large differences between coastal and interior provinces.
 India and Indonesia in the late 1990s were, respectively, at about 2400 and 2600 kcal/day. This would have provided adequate nutrition for everybody only if the two countries had a perfectly egalitarian access to food; in reality, highly skewed income distribution makes India the country with the largest number of undernour-ished people (FAO, 2000). Many sub-Saharan African countries average less than2200 kcal/day, some even less than 2000 kcal/day, and these obviously inadequate food supplies are re ected in the world’s shortest life expectancies at birth. Even when adequate in terms of total energy and protein, typical diets in most developing coun-tries are monotonous. And, unlike in af uent nations where nearly all traces of sea-sonal food supply have been erased by international trade, diets in many poor countries still strongly re ect the seasonality of plant harvests or fish catches.

25                                               Fruit
                                                                              Aquatic products
1970 1980 1990 1999
Figure 3.4
Dramatic changes in China’s average per capita food supply brought by Deng Xiaoping’s post-1980 economic reforms exemplify a rapid dietary transition in a modernizing country. Based on data from State Statistical Bureau (1980–2000); these figures exaggerate actual meat consumption (see the text for details).


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