|Who's Hungry? And how do we know? Food Shortage, poverty and deprivation (United Nations University - UNU, 1998, 199 pages)|
The significance of hunger lies primarily in the damage it does to those who suffer it, and secondarily in the ramifications of efforts made to avoid it. Figure 1.1 shows how some of the consequences at the individual level can easily lead to extreme changes at the other levels of social organization. This figure is a great oversimplification of both the causes and consequences of hunger but it helps highlight some of the significant relationships between hunger and human development, including the impact of hunger on the environment, economic growth, health and family planning, and political order.
Some of the possible consequences of food shortage, food poverty, and food deprivation are presented below, along with further explication of the causal relationships between these consequences. We begin with a relatively lengthy discussion of the effects of food deprivation, in order to increase awareness of how devastating hunger is for the individual; this in turn will facilitate understanding of how individual hunger profoundly affects the social order. This is clear from the conceptual framework.
Effects of hunger on the individual
We define individual hunger as consumption of a diet insufficient to support normal growth, health, and activity. This definition leaves open questions of whether norms are fixed across populations and over time, and of what nutritional requirements are associated with them. These questions, each the subject of considerable controversy, are discussed in subsequent chapters. In the sense we use the term, hunger does not necessarily imply appetite. Individuals may eat enough of certain bulky diets to feel satiated and yet obtain fewer calories and less of some or all nutrients than they need, while those who eat enough of a more nutrient-dense diet to satisfy their appetites may also be malnourished and vulnerable to diet-related chronic disease: excessive fat is growing as a dietary problem in urban communities in developing countries. The physiological effects of hunger vary according to the particular nutrient(s) deficient (or in excess) in the diet and also the age, health, and reproductive status of the individual. The discussion below focuses first on protein-energy malnutrition and then turns to micronutrient deficiencies. Variations in the impact of malnutrition over the life cycle are taken up in the following section on effects of hunger on the household.
The combined insufficiency of calories and protein, or protein-energy malnutrition (PEM), is now considered to be the most widespread form of hunger. Although protein deficiency - including its severe clinical form, kwashiorkor - was once considered the predominant form of undernutrition, nutritionists now agree that most traditional vegetarian diets, consumed in quantities sufficient to meet energy needs, generally provide adequate protein as well, even where animal foods are absent.
Nevertheless, some of those subsisting on largely grain- or tuber-based diets may be at risk of protein deficiency. Young children (particularly weanlings) need more nutrient-dense, protein-rich foods because of their smaller intake capacities. There is mounting evidence that, even if weaning foods are eaten in sufficient quantity to meet energy requirements, there may be important protein and micronutrient deficiencies (Allen et al. 1991; Brown 1991; Golden and Golden 1991; McGuire 1991; Pollitt 1991; West 1991).
Protein quality may also be a problem for poorer segments of the population who may not be able to afford the more expensive non-grain elements in traditional combinations of vegetable foods that together make complete proteins. If they must subsist on only grain, rather than roots or grains with a complementary sauce or garnish (or with another vegetable food that provides the rest of the amino acids to make a complete protein), the quality of protein available to them is less satisfactory. The manifestations of severe protein deficiency overlap with conditions caused by inadequate caloric intake, but protein deficiency carries with it additional problems from fat accumulation in the liver, oedema, and severe anaemia (Hamilton et al. 1985).
When diets are also inadequate in energy, individuals adjust by reducing expenditures through curtailment of physical activity. This behavioural shift has an emotional analogue in apathy (including reduced appetite) and irritability. The costs are obviously reductions in work, in socializing, and, for children, in the interaction with their environment that contributes to their learning and development.
Some physiological adaptation to scarcity also occurs: the basal metabolic rate, or use of energy to power such basic and essential life processes as respiration and circulation, is reduced. But such adaptations have limits that vary across individuals and possibly within individuals over time; causes of this variation are not well understood. These should be viewed as "adjustments" to scarcity that are made at some cost to the well-being of most individuals.
Another consequence of low energy intakes is reduced growth (in children) or weight loss. Energy expenditure may be maintained at a level in excess of consumption by metabolizing reserves in the form of stored body fat. Later, lean body mass in the form of muscle and even organ tissue will also be consumed if inadequate intake persists. Weight loss accompanies the initial stages of inadequate energy in take but, if prolonged, is followed by wasting - in its severe clinical form, marasmus. Death from starvation is the ultimate outcome where intake less than expenditure continues long enough. However, most hunger-related deaths are due to infectious disease rather than starvation per se: with severe malnutrition, ability to resist infection deteriorates sharply.
The relationship between malnutrition and infection is a reciprocal and synergistic one. Disease leads to a deterioration in nutritional status at the same time that malnutrition increases susceptibility to disease. Effects of disease on nutritional status involve shifts in the types and quantities of foods consumed (whether due to custom or loss of appetite) and to decreased absorption and diarrhoea. Parasitic organisms, as in malaria or schistosomiasis, or intestinal worms, divert nutrients for their own use. Energy, protein, and micronutrient needs are elevated in order to fight off infection. Immune function also deteriorates with extreme PEM; evidence is more mixed as to possible increases in susceptibility to infection with mild to moderate malnutrition.
Functionally, we observe the effect of sustained hunger far short of starvation largely as lethargy. Ability to carry out heavy manual labour is impaired; the periods over which substantial physical effort can be maintained are reduced. An undernourished manual worker is likely to be less productive than a well-nourished one, to need longer breaks between periods of effort, to be able to work fewer hours per day, and to need to spend more of his non-working time resting. Even aside from performance on the job, the restriction of physical activity clearly implies a reduced quality of life.
In children, the additional effects of even mild to moderate PEM are delayed or permanently stunted growth and higher morbidity and, ultimately, mortality. Although public health statistics tend to ascribe child deaths to either malnutrition or infectious disease, such causes tend to be interlinked. Quantifying the interaction for a series of case studies from developing countries, David Pelletier concluded that malnutrition contributed to 56 per cent of all child deaths, owing to its potentiating effect on infectious disease. About 83 per cent of these malnutrition-related deaths were attributed to mild-to-moderate malnutrition (Pelletier 1994). These findings highlight the magnitude of the problem of food deprivation as a contributor to mortality in young children. Elevated morbidity and mortality are also associated with micronutrient malnutrition, especially vitamin A and iron deficiencies.
Even if food is consumed in quantities sufficient to meet both caloric and protein needs, requirements for various vitamins and minerals may go unsatisfied. Three major micronutrient deficiencies are considered important public health problems today, meaning both that they affect large numbers of people and that their consequences are severe: these are deficiencies of iron, iodine, and vitamin A. Specific micronutrient deficiencies are associated with distinct problems in health and function.
Iron deficiency is believed to be the most common micronutrient deficiency in the world today. It appears, from incomplete evidence, to be most common in South Asia and Africa. About 22 per cent of the world's population is thought to have deficiencies of iron extreme enough to cause anaemia (Ralte 1996). Iron deficiency is especially common among reproductive-aged women, whose requirements are higher than those of others. Although traditional diets throughout most of the world seem to provide large amounts of iron, its biological availability varies according to source. Iron from animal sources is relatively well absorbed (that from human milk best of all); that from grains and vegetables less so. Parasites that divert the body's iron to their own use and/or cause faecal blood loss may also produce iron deficiency.
Iron is used in the transport of oxygen in the blood, and most of the problems associated with its deficiency relate to inadequate supplies of oxygen reaching the cells in which it is needed. Even mild deficiencies of iron seem to be associated with lack of physical energy and difficulties in concentration, with resulting losses of work productivity for adults and of education for children. Iron deficiency anaemia, although common, is increasingly recognized as only the most extreme form of a nutritional problem affecting many more people. Anaemia and subclinical iron deficiency are products and markers of impoverished, unhygienic, and unhealthy environments. Long-term consequences of iron deficiency tend to perpetuate poverty by reducing physical and cognitive development and function of those that are iron deprived.
The next most common micronutrient deficiency is iodine deficiency, with an estimated 655 million cases of goitre (Millman et al. 1991; Ralte 1996) and almost 6 million cretins worldwide (Grant 1995). The most severe problem is geographically restricted to areas with iodine-poor soils that are typically mountainous, glaciated, and/or subject to heavy rainfall or flooding. Milder forms may occur in these and other regions (including industrially developed European countries) where intakes of iodine-adequate foods are low. Goitrogenic substances may also induce iodine deficiency despite apparently good iodine supply. Where soil has inadequate amounts of iodine, insufficient amounts are present both in plants and in animals fed on those plants. Within affected areas, deficiency is most common for those whose diet is most restricted to locally grown foods. Consumption of imported foods tends to be protective. Where locally grown foods are cheaper, we also may expect an association of iodine deficiency with poverty within affected regions. The greatest concentrations of population in areas of iodine deficiency are found in South-East Asia, although there are also pockets of severely affected populations in Africa and Latin America.
Effects of this iodine deficiency disease are both physical and mental. Cretinism, which is irreversible, results from severe iodine deficiency during gestation. The condition combines "profound mental deficiency, a characteristic appearance, a shuffling gait, and a spastic dysphasia" (Scrimshaw 1990). Goitre, a pronounced swelling of the thyroid gland, may develop at any time. High rates of milder mental impairment have been found in areas in which goitre and cretinism occur, and it is now believed that those visibly affected are only a fraction of those whose function is impaired. UNICEF has estimated that 30 per cent of the world's population is at risk of mental and physical impairment due to iodine deficiency, even though less than half of that number manifest signs of goitre or cretinism (Grant 1995). According to one authority (Stanbury 1991), "Iodine deficiency is the most frequent cause of preventable mental retardation today."
Deficiency of vitamin A was estimated to affect some 231 million children in 1994 (Grant 1995), over half of them in just three countries - Bangladesh, India, and Indonesia. Vitamin A is provided by a wide range of vegetable and animal sources but children, especially, may lack adequate access, owing to culture or economic restrictions in diet.
Vitamin A deficiency is a major cause of blindness, mainly in childhood. Many of those blinded die shortly thereafter. It has also been linked to greatly increased vulnerability to infectious disease, with some studies claiming dramatic reduction in child mortality when vitamin A supplementation is provided to all children in areas in which even a few show the visible signs of vitamin A deficiency. Controversy continues on the linkage to mortality from infectious disease (Hussey and Klein 1990; Ramachandran 1991; Rathmathullah et al. 1990). However, most authorities seem to agree that, in at least some populations, vitamin A deficiency is a major contributor to high death rates in childhood. Even mild vitamin A deficiency has been associated with increased vulnerability to respiratory infections, diarrhoea, and complications of measles, all of which are major causes of death among children in many less-developed countries (Tomkins and Watson 1989).
Other micronutrient deficiencies are less common than these three but may be significant in certain populations or settings. Pellagra, beriberi, scurvy, and rickets, associated respectively with deficiencies of niacin, thiamine, vitamin C, and vitamin D, were important public health problems in the past but are now relatively rare. They are sometimes observed, however, among refugee populations subsisting on food aid rations based on an unusually restricted range of foods (Chen 1990). In addition, zinc deficiency lately is becoming recognized as a significant contributing factor to poor health and growth, although the absence of a reliable index of human zinc deficiency and of obvious clinical features make diagnosis and assessment of impairments uncertain (Cousins and Hempe 1990).
Detailed data on the prevalence of these micronutrient deficiencies in specific groups and locations are scarce and unstandardized, and they will not be explored further in this volume. Overall, recent advances in the study of each of the major micronutrient deficiencies suggest that effects are far more widely distributed than previously believed and that the subtler and less visible effects of milder forms of iron deficiency, iodine deficiency, and vitamin A deficiency on mental function and vulnerability to disease may dwarf their more easily identified manifestations in total impact. Increasing attention to these problems will add to our store of knowledge about who is affected.
Effects of hunger on the household
Households with hungry members face limitations that affect both their current daily activities and their longer-term welfare. Hungry mothers are less able to nourish and care for their children, maintain household functioning, and provide additional household resources to improve nutrition. Hungry workers generally earn less and have less energy for household maintenance activities. Hungry members are usually sick more often; this reduces household productivity in the short and over the longer term and also creates a demand for
additional medical care, which may go unmet because of limitations of time and money. The following two sections outline mechanisms through which hunger is transmitted intergenerationally.
Hunger among mothers and children
The malnutrition of pregnant women may lead to serious problems for their unborn children. Most dramatic is cretinism resulting from severe maternal iodine deficiency, discussed above. More commonly, children born to chronically undernourished women are likely to be small at birth. Low birth weight, which is associated with increased risk of mortality and with a range of health and developmental problems for survivors, may result either from premature delivery or from retarded intrauterine development. Maternal malnutrition is not the only cause of low birth weight but it is an important one. Women do not have to be malnourished during pregnancy to disadvantage their children; undernutrition during their own childhoods can cause growth stunting and influences the size of the child a woman can later bear. Maternal pelvic size is a strong determinant of neonatal survival and it is universally correlated with height in populations. The proportions of low birth-weight infants are much higher in populations identified as poorly nourished according to adult anthropometric indicators, ranging from lows of 4-6 per cent in many affluent countries to values of 25 per cent or greater in Pakistan, India, Bangladesh, and Laos (Grant 1990).
A mother's malnutrition may also limit her ability to breast-feed
her infant. Quantity and quality of breastmilk are reduced in women who are
severely undernourished, although lactation is often quite successful for
mothers who are moderately malnourished. Especially under conditions of poverty,
illiteracy, and poor sanitation, any threat to a mother's ability to breast-feed
her baby is a threat to that baby's health and development. While affluent and
well-educated mothers may safely choose to use commercial infant formula rather
than breast-feed, the alternatives available to the very women whose own
nutrition is likeliest to be marginal are less satisfactory and even life
threatening. Alternative foods and breastmilk substitutes are lower in
nutritional value and are likely to be contaminated. The additional
immunological protection that breastmilk gives the infant is especially
important under these conditions. Breastmilk substitutes are also relatively
costly. They take resources that might otherwise be
devoted to nutrition for other members of the household and therefore influence the health and nutrition of the entire household.
A young child's malnutrition influences not only its immediate health and well-being but also its later development. Where a child consumes less energy, it is less active. Avoidance of physical activity translates into a reduction in play and exploration and therefore impaired acquisition of communication, reasoning, and problem-solving skills. A child rendered apathetic, passive, and perhaps irritable by malnutrition invites less interaction with others. Cleland (1990) reviewed evidence that children receiving food supplements were more effective at communicating their needs than unsupplemented children. He also suggested that undernutrition of the whole family contributes to a more passive style of child care that causes health problems other than undernutrition to remain unaddressed.
In children, an additional adjustment to undernutrition is the slowing or cessation of physical growth. This is particularly damaging where the timing coincides with critical growth spurts, although growth shortfalls associated with hunger episodes usually can be made up if subsequent intake is sufficient to sustain catch-up growth as well as normal requirements. However, where hunger episodes alternate with periods of intake adequate only for normal needs, growth shortfalls may be permanent and cumulative. Early nutritional damage may be permanent in the absence of intensive remedial efforts.
Nutritional supplementation in impoverished conditions clearly has important benefits but its efficacy may also be limited. Longitudinal studies have shown that those receiving protein and energy supplementation at two years of age had better cognitive and occupational performance in adulthood (Chavez et al. 1995; Martorell 1995). In contrast, slum children receiving 1-4 years of nutritional supplementation and additional stimulation have been shown to lag behind those in more advantaged families (Luster et al. 1989). Supplemented slum children outperformed others in their community, but the interventions were not enough to overcome their social disadvantage.
Special advantages for workers
Children's nutrient needs notwithstanding, the intrahousehold distribution of food has been shown sometimes to favour workers, who receive more food relative to need and more stable intakes despite seasonal fluctuations in household food availability (Gross and Underwood 1971; Van Esterik 1984). Patterns of discrimination that favour the most productive member(s) may be to the advantage even of those against whom they discriminate, if the protection of earning capacity protects the household's continued access to food and prevents further deterioration in nutritional status of most members.
Maternal nutrition may be especially important, since mothers usually manage the food, health, and care for all members. In addition, wages from maternal work have been shown to contribute directly to household food budgets and particularly the food available to children. Time diverted from meal preparation, however, can decrease dietary quality. Maternal work also may affect the intake of young children if they divert time from breast-feeding, special weaning-food preparation, or frequent feedings of toddlers (FAO 1987).
Food-poor households usually react to scarcity by seeking additional means of entitlement to food, including migratory wage labour, especially in urban areas. This reduces the number of consumers at home and adds migrant remittances to the household income stream. However, the irregularity of migrant remittances can contribute to inconsistent intake patterns. Also, reductions in labour available within the household have been known to cause shifts in household food production toward less labour-intensive crops, which are also often lower in nutritional value; non-staple crops such as vegetables may also be abandoned (Benería and Sen 1986; Tabatabai 1988). In sum, household strategies are designed to protect the nutrition and productivity of working members but demonstrate several disadvantages: they may further marginalize and undermine the nutritional status of dependents, they may not provide income security, and they may disrupt local subsistence production by diverting labour to other enterprises.
Effects of hunger beyond the household
Hunger cumulatively has effects beyond the household. Hunger and the threat of hunger are significant forces for social polarization. Strategies for avoiding hunger, misnamed "coping mechanisms," may permanently alter class and ethnic relations within communities and regions. For example, when other forms of entitlements fail, households are often forced to sell their productive assets to buy food. If many households in the same area are driven to employ the same strategy at the same time, all are likely to face depressed prices for their assets, from which the more secure households that are able to buy these assets improve their relative position. Actions to avoid hunger in the short run may jeopardize access to food in the long run and leave some permanently in food poverty, or at least more vulnerable to any further shocks. Whole populations may be forced to migrate in search of food, in the process disrupting development potential in a locality or region and encouraging political disorder and conflict.
The deleterious effects of hunger on individual work capacity also make it, in itself, a major obstacle to development. Households are not always able to nourish adequately even their most productive members. The low incomes and high energy expenditures usually associated with manual labour imply that those who need the most food can often afford the least.
Hunger also influences the next generation along multiple pathways. The biological changes brought about by hunger lead to altered behavioural and cognitive functioning, which in turn may condition social, economic, and political processes. Both economic development and family planning appear to be tied to effective schooling, but hunger directly affects children's ability to function in school and it increases incentives for families to keep their children out of school so that they can contribute to household income for food. The next generation, therefore, is less nutritionally prepared to improve its position.
The combination of low educational achievement and higher mortality rates among hungry families create a context in which limiting family size makes little economic sense. There are many other ways in which poverty contributes to population growth, but labour needs within households are particularly high where agricultural conditions are poor and where income diversification is an important means of assuring that some income will be available. High mortality decreases labour availability, and high childhood mortality dictates that sensible risk-minimizing strategies will include large numbers of births. It may seem counter-intuitive that families with few resources would not want to limit the number of ways those resources need to be divided, but this paradox can be best understood in this context of constant struggling for entitlement to food.