Most countries have enough food to meet their people's requirements. Malnutrition, however, persists in almost all countries.
The most common form of malnutrition in developing countries is undernutrition, in which food intake is inadequate to meet the body's energy requirements. In these countries, inadequate food intake is the usual cause of specific nutrition-related diseases and is a major force behind increased rates of infection, infant mortality, reduced productivity, and shortened lifespans. An estimated 1520 percent of people in developing countries eat too little to maintain good health. In some countries, more than 50 percent are deficient in one or more nutrients.
Populations of developed countries, on the other hand, suffer primarily from overnutrition caused by eating too many calories derived from fat and refined sugar. Overnutrition is associated with a high prevalence of obesity and chronic diseases such as coronary heart disease, hypertension, and diabetes.
In most developing countries, the adequacy of food supplies at the national level does not ensure that adequate food is available at the regional, household, or individual level. Factors that can influence the ability of individuals to acquire and utilize nutrients include: local food and water availability, food prices, a country's capacity to import food, incomes and purchasing power, women's workload and education level, local customs and food taboos, sanitary conditions, and health status.
Thus, because these social, political, and economic factors contribute to malnutrition, solutions require more than the provision of food and nutrients. There are interrelationships among malnutrition, poverty, and economic development.
This chapter reviews the composition of diets in developing countries and the common types of nutrient deficiencies associated with these diets. In addition, we identify factors that may contribute to improvements in food intake—such as storage, preservation, and preparation of foods. Finally, we examine domestic production and income factors that may affect nutritional status.
Defining an Adequate Diet
Nearly 50 nutrients—including water, carbohydrates, protein, fat, vitamins, and minerals—are necessary to sustain life. Not all of these substances, however, are needed on a daily basis, as the human body is capable of drawing on reserves. Daily energy requirements vary widely. Individuals will often adapt to a lower caloric intake by reducing physical activity. Energy needs and nutrient requirements are thus a function of sex, age, weight, activity level, and health status. Some nutrient requirements increase significantly during periods of infection, pregnancy, and lactation. Failure to absorb nutrients from foods due to parasitic infection or other diseases can also significantly affect nutritional status. Infants and children are particularly vulnerable because of their growth requirements.
Calorie Intake in Developing Countries
Inadequate energy intake is one of the primary nutrition problems in developing countries. An estimated 350-500 million people worldwide are not consuming enough food to meet their energy needs. Low calorie intake is closely related to reduced consumption of protein, vitamins, and minerals.
The average daily per capita calorie intake across all developing countries was 2,486 in 1989. Although this represents an increase of nearly 7 percent since 1980 and a 23-percent jump since 1961, Africa, as well as many countries and individuals, continue to lag far behind the developing country average.
Africa continues to lag behind the rest of the developing world in calorie intake, while Latin America and Asia have increased calorie consumption dramatically since the early 1960's. Daily energy intake in sub-Saharan Africa declined in the early 1980's as the continent struggled to overcome the combined impact of drought, rapid population growth, declining per capita incomes, rising oil prices, worldwide inflation, increased debt burdens, declining commodity prices, and civil conflict.
Increased calorie intake in Asia was largely concentrated in China and the newly industrialized countries, including South Korea, Thailand, Singapore, Hong Kong, and Malaysia. In Latin America, large caloric increases occurred in Costa Rica and Mexico. It is important to note that these regional increases in Asia and Latin America mask many continuing deficiencies in some countries and communities. Widespread malnutrition persists within many countries in the two regions.
Staple Foods in Developing Countries
Dietary composition plays an important role in nutritional status. An ample and diverse supply of calories, protein, vitamins, and minerals is necessary for good nutrition. Diets in developing countries consist largely of carbohydrates, usually obtained from one or two staple foods. Staple foods vary by country depending on local cultures and growing conditions, but they consist primarily of cereals (such as rice, wheat, corn, sorghum, and millet) and starchy roots (including cassava, sweet potatoes, and yams). These foods are sometimes prepared with small amounts of vegetable oils and are flavored with locally available condiments, spices, and/or sweeteners.
Carbohydrates account for more than 70 percent of calories in some developing countries, compared to 40-50 percent in the developed world. Diets generally lack variety and are low in fruits and vegetables, important sources of vitamins and minerals. This lack of diversity may be especially severe in rural areas, which have limited access to markets and thus rely heavily on a small number of locally produced food items.
The main sources of protein in developing countries are cereals, legumes, and pulses, including dried beans and peas, rather than animal products. Animal products, which account for more than 30 percent of total calories in the developed world, made up less than 9 percent of total calories in developing countries in the 1980's. Consumption of animal products was highest in Latin America, where such foods are an important part of the diet in a number of countries including Uruguay, Argentina, and other cattle-producing countries. Intake of animal foods was lowest in Africa which, with few exceptions, has a poorly developed livestock sector and lacks the purchasing power to import such items.
Nutritional Value of Staples
Diets in developing countries consist of foods that have important nutritional value if consumed in adequate amounts. In fact, many local foods that traditionally are prepared with a minimum of processing, such as sorghum and millet in Africa, are actually more nutritious than highly refined corn and wheat flours that are demanded in urban areas across many regions. The overconsumption of fats, a major public health problem in developed countries, is generally not a problem in developing countries, where fat intake is often inadequate. Fats account for less than 20 percent of total calories in the developing world, compared with 35-40 percent in some developed countries.
Fat intake is lowest in Asia, where it accounts for less than 16 percent of total calories. In Africa, vegetable oils, cereals, and oil-crops such as groundnuts are the main sources of dietary fats. Although cereals are low in fat, they are important sources of fat in Africa and Asia, where cereals account for more than two-thirds of dietary calories. Consumption of meat, dairy products, and animal fats, such as butter and lard, continues to increase in the developing world. Particularly in Latin America, the Middle East, and North Africa, total fat intake is likely to significantly increase.
Although protein deficiency was once thought to be a major problem in developing countries, recent research indicates that cormbining cereal-based diets with small amounts of other protein foods, such as pulses, groundnuts, or animal products, can adequately meet protein needs if energy intake is sufficient. One example of this would be combining rice with beans. Widespread consumption of animal products is neither necessary nor realistic given the current income limitations of large segments of the developing world, although small quantities may be useful in preventing iron deficiency, and in ensuring adequate nutrition in children and pregnant women. Moreover, excessive intake of animal products is associated with chronic and degenerative diseases commonly seen in the Western industrialized nations.
Income Growth and Dietary Changes
While income is one of the most important determinants of diet and nutritional status, it is not necessarily true that higher incomes translate into improved nutritional status. Economic development often results in the increased consumption of fats and protein and a reduction in the quantity and quality of carbohydrates. Results of an FAO study indicate that calories from fats increased from 10 percent in low income groups to 40 percent in the highest income groups. As incomes rise, there is a decrease in calories from starchy foods (cereals, tubers), an increase in calories from refined sugar, and eventually an increase in the consumption of animal products.
Nutrition-Related Deficiencies and Diseases
The combination of low overall energy intake, dietary composition, environmental factors, and the presence of parasitic infections is responsible for many nutrition-related deficiencies and diseases. The four most important forms of malnutrition in developing countries are protein-energy malnutrition (PEM), iron-deficiency anemia, xerophthalmia (a condition linked to vitamin A deficiency that can lead to blindness), and endemic goiter and cretinism.
PEM is a disease stemming from the coincidental lack of protein and calories. This is most commonly found in infants and young children; it increases the occurrence and severity of infections and ultimately affects growth and mental development. PEM and hunger can also cause low birth weight babies. Low birth weight babies, less than 2,500 grams or 5.5 pounds, are more than twice as likely in developing countries than developed. These children are more susceptible to infection and develop more slowly.
Kwashiorkor and marasmus are two severe diseases which stem directly from PEM. Kwashiorkor results from long-term protein deficiency brought on by inadequate energy intake and is characterized by a severe swelling of body tissues, reddish hair, and liver damage. Children between the ages of 1 and 2 are most vulnerable. Marasmus is characterized by severe energy deficiency and weight loss due to the steady wasting of fat and muscle tissues. Both diseases increase the risk and severity of infections by impairing the immune system. For example, a common cold can quickly lead to pneumonia and death.
Measures to reduce the prevalence of PEM include:
- Encouraging breastfeeding (which results in improved immunity, less chronic diarrhea, and increased iron absorption),
- Increasing consumption of cereals and legumes in place of starchy roots,
- Controlling infections and parasitic diseases through improved sanitation and health care,
- Increasing meal frequency of younger children, and
- Encouraging increased consumption of oils and fats.
Oral rehydration therapy (ORT) is an important mechanism for reducing the impact of diarrhea on nutritional status, particularly in young children.
Vitamin A deficiency, which causes blindness in more than half a million children annually, is linked to a lack of green leafy and deep orange vegetables. Deficiency of this essential nutrient also is implicated in increased mortality rates from childhood diseases, particularly measles and diseases of the respiratory tract.
Iodine deficiency occurs most often in the inland areas of Africa and Asia where soils and agricultural crops are naturally low in the mineral. The deficiency leads to an enlargement of the thyroid gland, producing a characteristic swelling of the neck known as goiter. Iodine deficiency can also cause an irreversible condition known as cretinism in children born to iodine-deficient mothers. Such children suffer both mental and physical retardation.
Iron-deficiency anemia is caused by low iron intake, stemming from a diet low in calories and lacking in variety. A dietary deficiency of vitamin C, which enhances iron absorption from foods, also contributes to anemia. This condition affects an estimated 1.3 billion people worldwide and is a particular problem among pregnant women, who have double the iron requirement of other women. Breastfeeding can significantly increase the iron available for infants. The high fiber content of diets based largely on carbohydrates, particularly those composed mainly of starchy roots, can significantly reduce the body's ability to absorb iron and other essential micronutrients.
Although undernutrition continues to be the overwhelming health problem in developing countries, there is evidence that increased consumption of Western-style diets among some affluent populations in developing countries has led to an increased incidence of diseases related to overnutrition. An FAO study documented a 105-percent increase in the incidence of diet-related noncommunicable diseases in parts of South America during the 1970's. As incomes, food availability, and food variety increase in the developing world, nutrition education will play an important role, particularly in populations that shift to urban areas. Education programs that encourage people in developing countries to avoid the overconsumption of calories, fats, and low-fiber foods may help improve their longterm health status as incomes grow and the demand for such foods increases.
Improving Nutritional Status
Chronic undernourishment is a function of deficient food intake as well as disease, lack of education, inadequate health care, inaccessibility to clean water, and poor sanitation.
Nutrition policies, including education, fortification, and supplementation, can play an important role in improving nutritional status. Nutrition education improves access to and utilization of locally available foods. Small changes in dietary composition—such as the addition of small amounts of wild greens and fruits or greens from locally cultivated starchy roots, such as cassava and sweet potato—can lead to dramatic reductions of vitamin and mineral deficiencies. Encouraging the use and productivity of home gardens can stimulate small-scale production that can provide essential nutrients.
Food fortification and direct supplementation can improve nutritional status, particularly in the case of micronutrient deficiencies. Iodine deficiency has been prevented in industrialized countries for most of this century through the addition of iodine to the salt supply. Iodine fortification is currently taking place in a number of developing countries, including some in Asia where programs are underway to fortify the supply of monosodium glutamate (MSG), a common food ingredient in most Asian households.
Since vitamin A can be stored by the body, periodic direct supplementation through vitamin tablets as infrequently as every 6 months is a relatively simple and inexpensive way to prevent deficiencies. In addition, many foods in developing countries, particularly starchy roots such as cassava and sweet potatoes, are rich in vitamin A. The high fiber content of such foods, however, particularly when used for weaning in infants and young children, significantly reduces the body's ability to absorb and utilize nutrients. Nutrition education which encourages the addition of small amounts of vegetable oils and fats to the diet in such cases can improve vitamin A status.
Prevention of iron deficiency is more problematic, since daily intakes are required. Fortification of bread and cereals may be a useful long-term solution. However, small changes in dietary composition can be important in the short term. For example, increased consumption of small amounts of animal products and vitamin C can improve iron absorption from plant products. Direct supplementation through the distribution of iron tablets, particularly for pregnant women, may also be important in the short term.
Policies targeted toward women that increase their access to agricultural and nutritional information can play an important role in improving the nutritional status of all household members. Since women are the primary care-providers and producers in the household, their role is critical in implementing changes in eating patterns and food choices. Saving women time by making improvements in food processing and providing better and closer sources of water can also be important short-term solutions.
Food Storage, Preservation, and Preparation
Improved storage facilities, better food preservation techniques, and increased development and use of local processing facilities can improve year-round food availability and, hence, nutritional status.
In some developing countries, postharvest losses due to insects, rodents, weather, and microorganisms (including mold), are as high as 5-30 percent for cereals and 15-60 percent for roots, tubers, fruits, and vegetables. Improved postharvest management practices on the farm, in marketing and processing concerns, and in the home can improve nutritional status through increased food availability and lower consumer prices.
Improved food preservation techniques in the home, such as drying, roasting, and fermentation, can significantly improve the nutritional and storage value of food. Encouraging countries to follow international food safety guidelines might lower the risk of infection or disease. This would require improved processing and food inspection procedures.
Domestic Food Production
Most regions of the world have experienced improvements in per capita food production. On average, per capita food output expanded more than 10 percent during the 1980's in developing countries. Asia experienced a small increase in per capita terms, while Latin America held steady. Africa is the exception, as per capita output there declined by about 5 percent during the decade.
Domestic production, however, is not the only determinant of food availability. Stocks and trade also work into the equation. There is not much information on stocks in developing countries, particularly for Africa where much is held on farms, so the focus of attention moves to trade. In many cases, imports have been significant enough to offset a shortfall in domestic production. However, financial constraints often limit imports.
Availability of food within a country is often not a problem; it is the lack of purchasing power that is the problem. Incomes in many developing countries are insufficient to purchase a nutritionally adequate diet. In 1990, per capita gross national product (GNP) in the developed countries exceeded $20,000. Incomes in developing countries averaged less than $1,000. The worst cases were South Asia and sub-Saharan Africa, where per capita GNP averaged $330 and $340, respectively. Per capita GNP in East. Asia exceeded $500, while in Latin America it neared $2,200.
The problem lies not only in the low income levels, but also the low growth rates. According to the World Bank, growth in real per capita gross domestic product (GDP) in developed countries averaged nearly 3 percent per year during the 1980's. On the other hand, GDP growth in developing countries averaged only 1.6 percent per year. The highest growth rate in a developing region—more than 6 percent—was experienced by East Asia. Growth in South Asia measured 3 percent. In sub-Saharan Africa and Latin America, per capita incomes declined 1.2 and 0.4 percent, respectively. Projections for the 1990's do not signal much hope for the poorest regions.
Exports account for a significant portion of developing country income. One of the principal reasons for both the low income levels and the low growth rates is the composition of exports from these countries. Primary commodities—such as oil, coffee, tea, cocoa, and cotton—account for more than half the exports of most African and Latin American countries. World trade in primary commodities is smaller than that in manufactured goods and, in addition, is growing more slowly. During 1980-89, annual growth in the trade of manufactured goods neared 5 percent, while the growth in trade of primary commodities was less than 2 percent. Oil exports, in volume terms, stagnated during the 1980's. Another concern is that the prices received for these commodities were cut in half during the 1980's.
Many developing-country governments have adopted an export-oriented strategy in order to reduce their dependence on primary commodity markets. By encouraging nontraditional exports, this strategy tends to increase export earnings, thus enabling a country to increase commercial imports in case of domestic production shortfalls.