During the 1990s, some African countries improved their food production and nutritional levels, but in others the number of hungry people increased. In fact, more than one-fourth of the population of Africa does not consume enough food to ensure healthy nutrition and support a productive life.
In many places, poverty is a main cause of hunger and malnutrition. Many people do not have access to enough food, simply because they lack sufficient income. Rural people often go hungry because they do not have access to good land, or they lack the knowledge and technology to make the land they do have more productive. In order to improve food production and raise nutritional levels, therefore, it is important to tap new potential. If appropriate technical advice and practical solutions are made available, it is possible to increase land productivity and enhance food diversity and dietary intake, even where people have small landholdings.
In general, children and pregnant and lactating women are most vulnerable to malnutrition because of their special dietary needs. Children who are underweight or have other signs of malnutrition are common in many parts of Africa. Some rural communities have local names to describe different signs or effects of malnutrition (e.g. night blindness, marasmus, and kwashiorkor), although they may not always be fully aware of their causes.
Malnutrition is one of the major causes of child mortality. One-quarter of African children do not reach their fifth birthdays. More than 10 percent of babies in sub-Saharan Africa have low birthweight (under 2.5 kg), resulting from their mother's poor health and nutritional intake prior to and during the pregnancy. Low birthweight is one of the major causes of infant illness and mortality.
The most common forms of malnutrition are protein-energy malnutrition (PEM) and deficiencies in three micronutrients, namely vitamin A, iron and iodine.
PROTEIN-ENERGY MALNUTRITION
Symptoms
Protein-energy malnutrition occurs when children do not get enough food to meet energy and nutrient needs. They become underweight, or wasted, and eventually, if they do not have an adequate diet for some months or years, they will fail to grow normally and become stunted (i.e. shorter and smaller than well-fed children of the same age). Malnourished children have less energy to play and run. They are often listless, look unhappy, learn slowly and have low resistance to infectious diseases.
Children with insufficient food for several months and who are susceptible to infections develop severe PEM known as marasmus. Signs of marasmus include extremely thin legs and arms, a sunken "old person's" face, a distended abdomen, and a tendency to feel miserable and cry a lot.
The other form of severe PEM is kwashiorkor, which is more complicated. Kwashiorkor also results from a lack of energy and nutrients, but there are other factors that cause some children to develop it, such as a severe lack of vitamin A or other micronutrients. The signs of kwashiorkor may appear quickly, often when a child has an infection or stops breastfeeding suddenly. The legs, arms and face of these children appear swollen (this is because of oedema, or fluid in the tissues), they develop a "moon face" (the skin is pale and thin and may be peeling), and their hair becomes pale and straighter than normal. These children may also be extremely unhappy or apathetic (lacking interest in the things around them). Some children show symptoms of marasmus and kwashiorkor at the same time (i.e. they are extremely thin but may also have oedema of the legs, arms and face). Unless they receive therapeutic feeding and medical treatment, children with severe PEM are likely to die.
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Causes
Children with PEM often come from poor families that do not produce enough food, or are without enough income to purchase adequate food. Sometimes children from well-off households become malnourished, not because the household lacks food but because their parents lack knowledge of the special food needs of young children, and of how to prepare balanced, safe and nutritious meals. Parents are not always sufficiently aware of the relationship between insufficient food intake and malnutrition.
Poor nutrition also can result from shortage of water, lack of fuelwood and cooking equipment for food preparation, or lack of time for proper child care or for regular visits to the health centre. Frequent infections caused by poor hygiene and sanitation also contribute to malnutrition.
Children who are frequently ill are more likely to become malnourished, since, while sick, they often lose their appetites and refuse to eat. And conversely, children who are malnourished have less resistance to infection and therefore become ill more frequently than children who are well nourished.
In order to ensure that children stay healthy, parents should provide them with a diet that contains sufficient energy and all the essential nutrients, including protein, vitamins and minerals. The diet should also be safe and free from germs and parasites. Children should be given clean drinking-water and taught to practise proper hygiene and sanitation (e.g. washing their hands before meals and after using the toilet).
Groups at risk
Adequate nutrition is essential at all stages of the life cycle, from birth to old age. Adequate dietary intake is particularly important, however, for infants and pre-school children since they are the most vulnerable to malnutrition. Pregnant and lactating women are also vulnerable, as are the elderly and people recovering from illnesses. Infants become malnourished if they do not get enough breastmilk or if complementary foods are introduced too late or do not provide the required energy and essential nutrients. From the age of six months, the mother's breastmilk becomes inadequate, and complementary foods (i.e. weaning foods) need to be introduced to support adequate child growth and development.
Assessment
Healthy children will increase their weight every month. Thus weight measurement, especially for infants and pre-schoolers, is the easiest way to determine if a child is suffering from PEM. A monthly weight measurement is extremely important for children under five years of age. When the measurement shows that a child is losing weight and becoming malnourished, preventive action must be taken quickly.
In many countries, rural health centre staff are trained to take children's weight measurements and record them on a growth chart. If children are weighed monthly, it is possible to know if they are growing normally. Unfortunately, scales are not available in all health centres and communities in Africa, in which case a tool known as a mid-upper-arm circumference (MUAC) measurement may be used to assess children's nutritional status.
Between the ages of one and five years, the thickness, or circumference, of a child's mid-upper-arm does not change much. This is because the arm muscles of a healthy, well-nourished child grow, while the fat that the child had as a baby decreases. So, when a healthy child is growing, arm circumference does not increase much. However, if a child is growing too slowly or losing weight, muscles do not grow larger, and the arm circumference will be smaller than normal. The MUAC of a well-nourished child is above 13.5 cm. When the circumference or thickness diminishes to between 13.5 and 12.5 cm, that child is considered moderately undernourished. If the thickness of the child's mid-upper-arm falls below 12.5 cm, the child is severely undernourished.
Malnutrition can be prevented if children are properly fed with sufficient foods that are not bulky, that contain sufficient energy and that are rich in all the essential vitamins and minerals. Information on foods for infants and young children is available in Information Sheets 4, "Nutritious and tasty snacks for young children", and 5, "Home processing and preparation of weaning foods", and Home Garden Technology Leaflet 3, "Ensuring good household nutrition on a daily basis".
MICRONUTRIENT DEFICIENCIES
In addition to macronutrients, such as carbohydrates, proteins and fats, the human body needs vitamins and minerals. Although the body needs only a small amount of vitamins and minerals (for this reason, they are generally referred to as micronutrients), a lack of sufficient micronutrients in the diet affects the health and development of both children and adults, and results in potentially life-threatening deficiency diseases. The three main vitamin and mineral deficiencies are: vitamin A deficiency, iron deficiency anaemia and iodine deficiency disorders.
Vitamin A deficiency
Vitamin A deficiency (VAD) is one of the most serious childhood nutritional diseases and is often associated with PEM. Vitamin A deficiency causes night blindness and, in more serious cases, may damage the eyes, cause total blindness, and increase the risk of infection and death. Each year, an estimated 300 000 children in developing countries lose their eyesight because of vitamin A deficiency, and two-thirds of these children are at risk of dying. VAD not only affects children but also adults, and pregnant and lactating women are at particular risk.
VAD occurs when a child or adult does not eat enough vitamin A-rich foods or enough fat. Fats and oils help in the absorption of vitamin A, so when a diet is low in fat, only small amounts of vitamin A are absorbed. Vitamin A deficiency is often worsened by health problems such as measles and diarrhoea, which also increase vitamin A needs.
VAD deficiency is particularly common in areas of low rainfall with distinct wet and dry seasons, and where the availability and regular consumption of green leafy vegetables and yellow- and orange-coloured fruits are seasonal. Its presence in a community is sometimes confirmed by a combination of a low consumption of foods rich in vitamin A and the use of local terms to describe night blindness.
The best way to prevent VAD deficiency is to encourage families to grow and eat foods that are rich in vitamin A all year. These include plant foods such as dark green leafy vegetables and yellow- or orange-coloured fruits, as well as the wide range of indigenous leafy vegetables. Among animal foods, liver is particularly rich in vitamin A. Before the introduction of weaning foods, breastmilk is the only source of vitamin A for the infant. Lactating mothers should therefore eat plenty of foods rich in vitamin A to meet their own needs as well as those of their breastfeeding child. Adequate fat or oil must also be consumed in order to ensure that vitamin A is well absorbed, particularly in the diets of children and of pregnant or lactating women.
Anaemia
Anaemia is the most widespread nutritional disorder in the world. The most common cause of nutritional anaemia is iron deficiency, or lack of iron in the diet. Other causes of anaemia are parasitic infections, such as hookworm, and the loss of blood during menstruation and childbirth. Iron is an important mineral that is needed to form red blood cells that transport oxygen in the blood.
People with anaemia usually have pale tongues and lips, and the inside rims of their eyelids are white. Anaemia reduces people's ability to work, increases tiredness and slows children's learning. The high-risk groups for anaemia are women, especially during pregnancy and soon after delivery; babies; young children; and adolescents, especially girls, who are growing fast.
Nutritional anaemia can be prevented by ensuring that women and children eat enough iron-rich foods (e.g. small amounts of liver, meat, fish and legumes such as bambara groundnuts and cowpeas). These foods must be eaten with foods rich in vitamin C (e.g. citrus fruits, guavas, papayas and some green vegetables), because vitamin C increases the absorption of iron. Another way to help prevent anaemia is to avoid drinking coffee or tea immediately after a meal because they contain substances that inhibit iron absorption.
Iodine deficiency
Iodine deficiency disorders (IDDs) are caused by a lack of iodine in food and in the soils in which food is grown. This deficiency is most common in areas where iodine in the soil has been washed away by rains, and in inland areas that do not have easy access to seafood.
The thyroid gland at the front of the neck stores and uses iodine for the production of the body's growth hormone. If there is insufficient iodine in the diet for a long time, signs of iodine deficiency disorders appear.
More than 1 000 million people in the world are at risk of IDDs such as goitre, which is indicated by a swelling of the thyroid gland; low birthweight; inhibited growth in children; and impaired mental development. In severe cases, IDDs can cause brain damage.
The use of iodized salt is an effective way to prevent IDDs and is highly recommended. In some areas, iodine is added to drinking-water, including village wells.
