FEATURES

Food for Thought - Nutrition and School Performance
Measuring Children - the Uses of Anthropometry
Malnutrition and Infection (part II)
Estimation of Flows of External Resources in relation to Nutrition

Food for Thought - Nutrition and School Performance

Children's education is hampered by malnutrition; pre-school and school health and nutrition programmes improve performance.

Not only has evidence for the extensive effects of nutrition on school performance been accumulating, but the beneficial effects of interventions are becoming better known. With attention focussing on basic education, for which an important step was the "Education for All" Conference in Bangkok in March 1990, the ACC/SCN's annual symposium was on the subject of "Nutrition and School Performance", held on 19 February 1990 as part of the SCN's 16th Session hosted by UNESCO in Paris. A book was published, sponsored by UNESCO and the ACC/SCN by Professor Ernesto Pollitt, University of Davis, California, which provided important background for the meeting. This book, "Malnutrition and Infection in the Classroom" is available through UNESCO and the ACC/SCN¹. A review was also commissioned from Dean Jamison and Joanne Leslie on "Health and Nutrition Considerations in Educational Planning"; and a paper by Ronald Israel on "Program and Policy Options" was prepared². These papers were presented at the Symposium, which was chaired by Dr Susan Van der Vynckt, UNESCO, and stimulated extensive discussion. The Symposium was summarized by Dr Pollitt. The Sub-Committee put forward a statement, endorsed by the ACC, drawing attention to the urgent need for effective control of health and nutrition problems of school children, and the likely benefits. This statement is shown in the box on page 2.

Nutrition affects school performance in many ways: malnutrition in the pre-school years leads to a child ill-prepared to benefit from schooling; hunger during the school day affects attention and learning capability; ill health and chronic malnutrition (here anaemia is particularly important) persisting during the crucial early years of education have a pernicious effect on educability.

Pointing out that while health outcomes may be difficult to define and translate into economic terms, Dr Pollitt suggests that educational variables can be exactly defined, scaled and quantified in economic terms. For example, enrollments rates, age of enrollment, drop outs, grades obtained, and the like, can be straightforwardly assessed. In practical terms for purposes of assessing nutritional effects, Pollitt uses four types of concern: aptitude, time-on-task, perseverance, and achievement. He demonstrates comprehensively in his book and in his presentation that "highly prevalent nutrition/health conditions are important determinants of educational outcome... improvements in health and nutrition offer a possibility of improving educational efficiency".

Delayed effects of early malnutrition

Malnutrition in pre-school years leads to stunting, and other results of malnutrition, and these have been widely observed to be associated with reduced school performance. Such relations do not prove that it is the malnutrition itself that is the problem - although it seems likely - and as Pollitt asserts "skeptics that attribute the developmental deficit observed among children with a history of undernutrition solely to the social environment face a formidable task of finding evidence that supports their position". This view was accepted by the SCN (as shown in the box) in saying that "malnutrition and infection during the pre-school period... are critical determinants of later school performance".

Physical damage to the child with protein-energy malnutrition (PEM) in the preschool years may or may not be the main cause of later difficulties. These may also relate to constrained psychological development from reduced play activity, for example. "Severe PEM during the pre-school years affects cognition and learning", says Pollitt. "In a population where malnutrition is endemic children with a history of severe and chronic PEM are handicapped in school... In those cases where the child's educational, social and psychological needs are met after rehabilitation from the episode of severe malnutrition, the handicap may be negligible". In other words, it is not that the child is necessarily irretrievably damaged, at least from PEM, but certainly needs every help he or she can get when attending school.

In other cases some of the damage of early malnutrition may be irreversible. Cretinism from iodine deficiency involves severe mental retardation. Here, the need is to prevent cretinism in the population, and iodine deficiency in the mother prior to pregnancy. Nonetheless, children with mild iodine deficiency do benefit in terms of increased activity and mental acuity from current iodine supplementation, although some damage could still have been done. Blindness and visual impairment following severe vitamin A deficiency may severely handicap education performance, and these too have to be prevented in the preschool years, as well as ensuring adequate vitamin A nutrition to school children.

Establishing the benefits of supplementation in the pre-school years on later school performance presents formidable problems of research. A few studies have demonstrated such an effect, most strikingly when other aspects of the child's environment were also improved. That is, when social interventions including stimulating the child were added to the dietary supplements and health care, clearer effects on development were found. In general, when interventions are effective in combatting preschool malnutrition, an important benefit can be expected in better performance at school later.

A. Statement on Nutrition, Health and School Performance 1. A symposium was held on 19 February on the subject of "Nutrition and School Performance". The following statement was approved by the Sub-Committee, which requested that it be endorsed by the ACC and disseminated widely. 2. "On the occasion of the 16th Session of the Sub-Committee on Nutrition [ACC/SCN] of the United Nations, a symposium was held at UNESCO's headquarters on the subject of nutrition and school performance. Informed by state-of-the-art presentations from experts in this field and by the extensive discussion that resulted among the participants, the SCN notes that consensus exists about the following: - Enough is now known to recommend health and nutrition programmes among efforts to increase school enrollment and learning. - Specific nutritional deficiencies and health conditions impact negatively on school enrollment, aptitudes, time spent in school, (i.e. attendance, drop-out rates) and achievement. Severe nutritional conditions (e.g. cretinism, blindness due to xerophthalmia, marasmus), as well as mild and moderate forms of these deficiencies, are known to be important factors contributing to the educational crisis facing developing countries. - Malnutrition and infection during the preschool period, interacting with environmental factors related to poverty, are critical determinants of later school performance. The evidence is unequivocal in demonstrating that, in this setting, short stature in school children, a product largely resulting from growth retardation in early childhood, is an indicator of risk of poor school performance. - Concurrent nutritional deficiencies and diseases plague school children, adding to developmental consequences of prior malnutrition. Short term hunger is known to affect attention and learning. Iron deficiency anaemia is linked to poor school performance. Parasitic diseases are most prevalent among school children and undoubtedly contribute to poor health and nutritional status and perhaps affect learning as well. 3. The education sector should promote activities in its own and other sectors that would combat early childhood malnutrition and morbidity and hence would represent an investment in human capital. It is explicitly clear that one of the benefits of said investment will be in the area of school performance and hence greater effectiveness of activities in the education sector. The school setting itself offers opportunities to correct health and nutrition problems of public health and education significance. Through proper attention to curricular content and activities in and out of school, the school setting also allows educators to alter behaviour and dietary practices to the benefit of future generations. School feeding programmes may also contribute to the correction of specific nutrient deficiencies and short term hunger. Vitamin and mineral supplements may be required. Efforts should also be included to combat parasitic diseases when appropriate. In general, feeding and health programmes should be so placed that they facilitate unconstrained growth and development throughout the school age period, including meeting the special needs of adolescents. 4. The SCN is of the view that the education sector should give increased importance to the control of health and nutrition problems of school children because effective actions of this nature will result in increased school enrollment, improved school performance, and efficiency. In particular, the SCN enthusiastically acknowledges UNESCO's recent efforts in initiating and stimulating interest and action in this area and its effective catalytic role in pulling together the other agencies and the scientific community on this issue. 5. SCN recommends that, having laid the groundwork, UNESCO will now take the leadership role in developing a programme to fulfill the potential for this important, but heretofore, largely neglected area. 6. Finally, the SCN hopes that the upcoming World Conference on Education For All fosters the political will necessary for successful implementation. " Source: Summary Report of the Sixteenth Session of the ACC Sub-Committee on Nutrition, UNESCO, Paris, 19-23 February, 1990.

Short term hunger

"Hunger interferes with problem solving and concentration abilities", according to Dr Pollitt. "Overall the children affected detrimentally in most cognitive tests by missing breakfast were those who were.... previously malnourished".

Attention, interest and learning may be adversely affected by short-term hunger - a daily observation of many school teachers and parents. Skipping breakfast or having an inadequate morning meal before coming to school is the usual reason. Although findings on the beneficial effects of school feeding for educability have been inconsistent, this may be related to the differences in study design and interpretation of the data. For instance, mid-morning feeding might substitute breakfast in some while supplement it for other experimental subjects; or the recipients experiencing short-term hunger may or may not be chronically malnourished. In the light of available evidence, however, provision of breakfast may well benefit school children emotionally and improve their attention, problem-solving ability and educability.

The research evidence was also reviewed by Drs Jamison and Leslie, who noted that school attendance is affected by hunger, and that several studies "show feeding children breakfast or a snack early in the school day can have a significant, positive effect on school performance". Indeed, the weight of opinion is swinging towards the view that "school feeding programmes designed to alleviate short term hunger (e.g. school breakfasts or school snack programmes) will be less expensive and equally or more beneficial in terms of school outcomes than more elaborate school lunch or multi-meal programmes designed to address chronic PEM". Children are encouraged in this way to attend school, and do better when there.

Current chronic malnutrition in school children

In Sub-Saharan Africa over 4% of school-age children (and in developing countries as a whole about 2%) will die before school completion. This is despite the fact that school children have the lowest annual risk of death compared to any age group. School children in developing countries are 14 times more likely to die than children of the same age in industrialized countries.

Good health and nutrition are needed for attention, regular school attendance and optimum class performance. Clearly educational capabilities can be significantly diminished in undernourished children not only because of impaired ability to concentrate and learn, and decreased educability, but also due to irregular school attendance, as an outcome of poor health and nutrition-related illnesses. Mild to moderate malnutrition may alter the processes associated with cognitive function leading to passivity, apathy, shortened attention span, reduced short-term memory, failure to acclimate to repetitive stimuli and a lag in the development of sensory-integrative capacity³.

Attention among iron deficient anaemic school children is impaired, and iron nutrition has been the subject of considerable attention. In particular, the effects of iron treatment among anaemic school children have been shown to result in significant improvement in some aspects of school performance. Of practical interest, it was found that adequate iron treatment over no more than three months reversed deficits observed among iron deficient anaemic school children. Although the mechanisms are not completely understood - anaemia may not be the only one (see SCN News No. 3, pages 13-14) - it is clear that anaemia is often involved, and controlling iron deficiency important.

A number of other aspects of health in school children were emphasized. In particular, parasitic infections from worms and schistosomiasis are very widespread, but open to control. Lead toxicity - a particular risk where gasoline is leaded in densely populated urban areas - is of particular concern. Indeed "this risk is likely to be even higher among iron deficient children", according to Pollitt. While it is felt justified to conclude that the risk of high blood levels of lead among school children living in large metropolitan areas in developing countries, ranging from Lagos to Cairo to Lima to Bangkok, is sufficiently high to be a public health concern, the direct linkage of lead toxicity to school performance has not yet been established. However, if lead is causing ill health, and ill health reduces school performance, a connection is likely to be there.

The research evidence for relationships between nutrition and measures of educational outcome was summarized as shown in Table 1.

Finally to illustrate the cumulative effect of many of his points, it is worth recalling Dr Pollitt's example of a study in which 89 children in four villages in rural Guatemala were followed through their six years of primary schooling. "Under ideal conditions each child represented a six year investment. In reality, only 15 children graduated in six years. At the rate of progress observed, 1,131 child-years of schooling would be needed to graduated the 89 children initially enrolled. The difference represents 520 child-years (47%) more than the ideal." The inefficiency, for the individual children, and for the education system, is clear.

Table 1. Strength of the association between nutritional and disease conditions, and educational outcomes

Time-on-Task
	Aptitudes	Enrollment	Absenteeism	Perseverance
Protein Energy Malnutrition	+++	++	Not likely to be related	Likely related but no data available
Iron Deficiency Anemia	+++	+	Not likely to be related	+
Iodine Deficiency Disorders (1)	+++	++	Not likely to be related	Likely related but no data available
Hunger	++	Suggestive evidence	Likely related but no data available	+
Intestinal Parasites	+++	Likely related but no data available	++	Likely related but no data available
Schistosomiasis	++	Likely related but no data available	Likely related but no data available	Likely related but no data available
Lead Toxicity	+++	Likely related but no data available	Not likely to be related	Likely related but no data available
Vitamin A Deficiency (2)	Likely effect through risk to health; data not compiled

Notes:	(1). Mild iodine deficiency disorder; cretinism not included.
	(2). Visually impaired or blind children require special education which is unavailable in most populations with endemic Vitamin A deficiency; this refers to possible effects of current mild Vitamin A deficiency in school children, mediated by effects on health.
Source:	Derived from Pollitt (1990), table 11.1 and text.

Turning problems into interventions

The nutritional problems clearly identified are short-term hunger, protein-energy malnutrition, and deficiencies of at least three key micronutrients, iodine, iron and vitamin A. Substantial consensus exists on the type of solutions, moreover on their likely high return on investment. Ronald Israel divided the interventions into short-term and long-term baskets. In the short-term basket would be nutrition supplements, school feeding, first aid, and treatment of parasitic diseases. In the long-run, environmental controls, school food production, dietary change and first aid would all be needed. The means of delivering such interventions was given in some detail by Jamison and Leslie.

These authors began with laying out the interventions needed to deal with pre-school malnutrition. "Community-based efforts to improve health and nutrition of pre-school age children are already a priority activity of the health sectors in most developing countries", they note. "The role of educational planners would be to lend the weight of their support to the importance of such efforts, and, in some cases, to advocate the application of resources to interventions that are particularly important in terms of later school outcome. Such interventions would certainly include, for example, addressing problems of micro-nutrient deficiency disorders in young children, which is not now a component of the standard child survival package."

Intervention	Relevant to	Nature of school intervention and estimate of cost considerations
School Facilities and Location	Diarrhoeal disease Lead Toxicity	Location of schools away from busy streets would reduce lead poisoning (and injury). Provision of water supplies and latrines would benefit hygiene. Costs depend on circumstances, but following estimates may be useful. Access to piped, stored or well water might cost in the range of $0.25 - $2.00 per student per year. Access to a functioning latrine might cost $0.1 - $0.5 per student per year.
School Health Worker	All conditions	The school health worker could be a nurse, or a teacher designated to be responsible for health and nutrition. The roles would be to provide contact and referrals to local health and family planning services, and/or a mobile team (see below). The school health worker could also provide health education, treat minor injuries, dispense chloroquine, iron supplements, etc. The main cost would be the teacher's time to supervise facilities and hygiene, liaise with health services, conduct health and nutrition education, dispense, etc. A commitment of 25% of one teacher's time per 500 students would generate a 1-2% increase in costs. Some training costs would also be incurred. Supplies might cost $1.00 to $2.00 per student per year for, e.g. chloroquine and iron supplements.
Mobile School Health Team	Micronutrient deficiencies Intestinal helminths Schistosomiasis	Mobile teams would visit schools probably once or twice a year. They would provide as needed: immunizations, supplements of vitamin A and iodine, treatment for helminthic infections; health nutrition or family planning education; consultation with school health workers, students, parents. They should service all school age children in the community, not just those enrolled. Costs are estimated to be around $0.5 to $2.00 per child per year, depending on the number of conditions treated per child.
School Feeding	Protein energy malnutrition Short-term hunger	Provision of adequate school meals (both in quantity and quality) may be expensive, but this will depend substantially on mechanisms for food preparation and delivery. Cost analyses are rare, but estimates from Brazil are of $12.00 per beneficiary per year, from Chile $15.00 per beneficiary per year (this was an extensive programme with breakfast and hot lunch). Efforts aimed primarily at relieving short-term hunger should focus on provision of breakfast or a small snack shortly after the students arrive at school. A small breakfast/snack (300 - 400 Kcals per day) might cost $20.00 to $40.00 per student per year; more substantial meals would cost more, but probably not proportionally.
Health, Nutrition and Family Planning Education	All conditions	Students, teachers and parents should be explicitly targeted by school-based information and motivational campaigns. In addition, appropriate nutrition, health and family planning information should be integrated into the regular curriculum. Although costs again are not well known, something useful could be done in the range from $0.1 to $0.5 per student per year.

Source: Extracted from tables 3.2 and 3.3 of Jamison and Leslie (1990) see end notes; please see paper for more details. Note that this refers to school interventions not those for the pre-school child which may also be essential for later school performance.

The school health worker idea is already quite widespread, and may involve designation of a teacher to be responsible for health and nutrition, and their training. This and other ideas have been promoted by UNESCO⁴. Costs and some of the functions of such an individual are referred to in the box.

Mobile school health teams are not yet used extensively, so there is limited experience in their operation and costs. This is one idea where some trials may be needed, and in the right circumstances such teams, visiting schools once or twice a year, might be cost-effective.

School feeding has a long history, and has been often evaluated. It is being repeatedly stressed that evaluation should look at effects on school attendance and performance, rather than on nutritional measures such as anthropometry - because school age children have limited capacity to catch-up in growth, as discussed in the later article on Uses of Anthropometry. "In general, school feeding programmes appear to have a significantly positive effect on school attendance in spite of limited evidence of a positive affect on nutritional status" (mainly growth), according to Jamison and Leslie. As noted earlier, the timing of school feeding - providing food early in the day - obviously has a better chance of helping children who arrive at school hungry.

The wide distribution and prestige of teachers and schools in developing countries give them a particular place in providing education and information on health and nutrition, for students and their families. Educating school children in health and nutrition practices and family planning can clearly have a most important long-term effect, when school children themselves become parents.

Helping girls remain in school

In many places, the participation of girls in the education system is relatively less than boys. This is for a variety of reasons, which are not gone into here, but it should be emphasized that particular attention to the health and nutrition of school girls is expected to help them remain in school. At the same time, the school system may be particularly useful for trying to supplement the diet of girls before puberty, to ensure that remaining growth potential is fully achieved at this critical stage. This would contribute to breaking the cycle of small mothers having low birth weight babies, who grow up to become small mothers again.

Economic benefits

Improving the use of the education system can be shown to bring benefits in terms of future productivity, and increased efficiency in using the capacity of the system itself. Jamison and Leslie provide estimates showing that even with conservative assumptions, benefits of investing in, for example, school feeding (the most expensive of the possible interventions) will far exceed costs. Better educated adults are clearly more productive, improving their own income and their contribution to the national economy.

The concept of installed capacity to provide educational services (analogous to hospital bed availability) has been used to assess the school system, and this can be developed, as suggested by Jamison and Leslie, to estimate capacity utilization. The idea is shown in Figure 1. This looks at two factors, both of which can be affected by health and nutrition interventions. First, there is inefficiency if the level of enrollment does not reach the number of places available - this is shown on the horizontal axis on the Figure. At the same time, the average daily attendance of pupils enrolled may be below the optimum and affected by ill health and malnutrition. This is shown on the vertical axis. Thus the extent to which the system capacity is utilized is shown by the cross-hatched area, and the inefficiency is illustrated by the proportion of the capacity (dotted) that is used. Expanding this proportion both by increased enrollment and better attendance can, it is suggested, be achieved at least partly by health and nutrition programmes.

Figure 1: Capacity Utilization in Schools

"Obviously, only part of this quantitative inefficiency results from poor health and malnutrition, of students or of teachers", say Jamison and Leslie. But it is probably an important part. The implication for educational planners may be that more investment in child health and nutrition will pay off well for education.

-J.B.M./M.L.

Comments from Dr R. Martorell (Stanford) and Dr S. Van der Vynckt (UNESCO) are gratefully acknowledged.

NOTES

(1) Malnutrition and Infection in the Classroom, Ernesto Pollitt, UNESCO, February 1990.

(2) Health and Nutrition Considerations in Educational Planning, Dean T. Jamison and Joanne Leslie, February 1990. Program and Policy Options for Improved School Nutrition, Health, and Learning in Developing Countries, Ronald C. Israel, February 1990.

(3) Levinger, B. (1989) - quoted by Jamison and Leslie: Effects of child health and nutrition on school performance.

(4) UNESCO, 1989, First Technical Report of the New UNESCO Project to Improve Primary School Performance through Improved Nutrition and Health. Paris: UNESCO.

Measuring Children - the Uses of Anthropometry

Current recommendations for appropriate measures and interpretation, for screening, growth monitoring, population surveys, and nutritional surveillance.

One appeal of using child growth - beyond its simplicity - is that almost everyone knows intuitively that when children are growing well, at least something is going right; but when children are becoming thin or stunted, something must be done. Child growth detects a problem well, but not its cause. This non-specificity has advantages: failed child growth catches many aspects of poverty and detrimental environment. But child growth has different features, primarily fatness or thinness (weight in relation to height), and linear growth or height. The uses of these measures depends on the circumstances, and the action that can be taken. In a crisis, severe thinness indicates serious risk; but chronic underfeeding and ill health cause stunting - shortness of height - often without thinness, and this growth failure is a sensitive way of detecting these. Such factors apply in principle to individuals and populations. But the handling of information, and consequent decisions, may vary.

"Malnutrition" and "nutritional status" have sometimes been used almost synonymously with low anthropometric measures⁴. This has implied that malnutrition is thinness or stunting. The issue goes beyond communication, important though it is, to touch upon the understanding of the problems we are trying to solve. Two steps have been taken to clear the air. First, the U.N. system in 1989 adopted a precise statement on the significance of small body size in populations - known colloquially as the SCN's statement on "big is better". The central point is that the process of becoming small, rather than smallness itself, is the concern⁵. This statement is given in box 3 at the end of this article. Second, a more rigorous specification of the causal mechanisms can be made.

This emphasizes that while a poor environment may cause both growth failure and sickness, growth failure itself does not lead to increased sickness. (This is discussed further with Figs 1 and 2 later). Anthropometry is a very useful measure of both a poor environment and risk of ill-health, death and constrained development. It is a measure of "nutrition", but it is not the same thing.

Because anthropometry is becoming so widely used, for individuals and populations, in crises and for chronic problems, and since there are options of measurement, who to measure, and how to calculate results, the SCN held a working meeting of scientists in June 1989 to put together "State-of-the-Art" recommendations on "Uses of Anthropometry". Much of this article is drawn from the report of that meeting, shortly to be published by the ACC/SCN⁶. The introductory statement of the meeting is given in Box 1.

Appropriate use of anthropometry depends on a correct understanding of the biological processes involved. Child growth and development, and energy balance in children and adults, are two of the main processes.

Energy balance in humans is buffered by body stores, in both children and adults. Food energy intake goes to fuel physiological functions (in children, including growth) and physical activity. Any imbalance is taken from, or added to, the body's stores of energy - stores in fat, as protein (in muscle) and for short-term use as carbohydrate (in the liver and muscle). These stores can be measured as weight. The equation is shown diagrammatically in figure 1. The "energy stores" are labelled "weight-for-height", more precise than weight alone which has a different meaning depending on the individual's height. Thus changes in weight, ideally, or if measurements have to be made at-one-time, thinness/fatness as weight-for-height, measure body stores and indicate the energy intake/expenditure balance. In adults, negative energy balance often means hunger and reduced activity, and if persistent means starvation. In children, concern is I also for their health and development, and growth as an integral part of this.

Figure 1. A portrayal of association between weight-for-height and the processes underlying energy balance.

BOX 1 Preamble (from June 1989 Workshop) "The most extensive public health problem among children in developing countries results from the complex of nutritional, biological and social deprivation that is manifest as ill health, growth retardation, functional disadvantages, and high mortality. Rates of physical growth and achieved body size mark the process of failing to grow and the state of having failed to grow, as such they are generalized markers of the syndrome of deprivation. Height and weight may also be used to mark the development of severe malnutrition in individuals. Anthropometry is particularly useful because it provides: - a practical way of describing the problem; - the best general proxy for constraints to human welfare among the poorest, including causes: of protein-energy deficiency, and environmental health risks; - excellent and feasible predictors at individual and population levels of subsequent ill-health and mortality; - an appropriate indicator of the success or failure of interventions related to a myriad of economic and environmental factors. Anthropometric information per se is non-specific and inadequate for identifying the cause of growth failure; anthropometry's usefulness stems from its close correlation with nutritional outcome and its socio-economic determinants. Because adverse economic and environmental factors lead - largely through dietary inadequacy and infection in poor communities - to growth failure, it follows that interventions may need to be directed at a number of points on the causal chain to effect recovery through improved diets and health promotion." Source: "Appropriate Uses of Anthropometric Indices in Children". A report based on an ACC/SCN Workshop, 12-14 June 1989, Geneva.

Figure 2. Environmental effects on the child.

The overall relation between diet, exposure to infection, and children's development is shown in figure 2. Mostly this illustrates what is well-known, except importantly that growth is a result alongside health and activity. It does not actually cause changes in these, but itself has a common precedent in diet and exposure to infection. Analytically, this means that anthropometric measures of growth are correlates of other concerns: thus they indicate causes and measure risk.

Figure 3. Influence of diet and other environmental factors (outside of box) on physiological processes in children (inside box) and outcomes (on right, outside box, underlined).

The mechanisms whereby diet and exposure to infection affect growth and development are now well understood, but the implications of these for interpreting anthropometry at different ages are only now being adequately stressed. For example, children of over two years old whose growth has been constrained may only slowly catch-up in height - if at all; but their body stores, fatness, may become normal for their height. This new emphasis on modifying interpretation by age is highlighted in the "Uses of Anthropometry" report. The mechanisms are shown in figure 3, where "past environmental influences" (last line in the box) refers to this effect.

The mechanisms shown in figure 3 are established physiology, but some of the feedback loops in particular merit renewed emphasis as central to the "malnutrition/infection" complex⁷ We can start with food intake, already influenced by infection by the common response to sickness of reduced appetite (anorexia). The digestion, absorption and transport of nutrients is affected by tissue integrity, itself requiring an adequate supply of nutrients at the cellular level; and also important in disease resistance. The supply of nutrients to cells and their utilization affects immune function, cycling back to mediate the response to infection. Finally, this supply affects tissue formation and hence growth.

The two large-scale aspects of growth, easily observed, are linear growth - height and frame - and body tissue (beside bone). (Microscopic aspects, such as tissue integrity, are not easily observed, but pathology is unlikely in the absence of growth failure where lack of dietary energy is the problem.) Thus the two main purposes of anthropometric measurement are to assess linear growth, and body mass given linear growth. These are commonly known as stunting and wasting (or thinness). These are of concern in different circumstances: very broadly, thinness in critical situations, and stunting in chronic deficits. Added to this, age must be considered.

Deficits in height take time to develop. Typically, a child in a bad environment will fail to grow as well as his well-nourished peers in both weight and height. But by age two it will be difficult to tell if the stunting is due to current or previous problems. Hence for immediate intervention thinness is more useful. A second complication is that by two years (or so), height deficits are difficult to reverse (because maturation has continued) - but this is less of a concern in itself, as it was the process of becoming stunted, not the stunting itself, that is the issue. The main message is that interpretation of anthropometric measures depends on age; and the distinction is usually made at around 2 years old.

The causes of wasting and stunting change with age, so the responses must too. At birth, infant weight and length are determined by maternal factors - including nutrition - and by whether the infant is full term. Interpretation of birth weight must take these into account. During the first 4 to 6 months, breast-feeding practices and maternal health (and ability to take care of the baby) are major influences on growth; growth failure at this early stage, less common than later, must be interpreted in this light. From around six months to two years, weaning practices and exposure to infectious disease have a crucial effect. As the age of the child increases, access to household food may have more importance; growth failure here, although often less pronounced, may begin to be more related to poverty, as breast-feeding and weaning practices have less influence.

What we are trying to measure, when and why

Anthropometry is aimed at measuring wasting, or thinness; and stunting, or retardation in linear growth. The proper measures for these two processes are weight-for-height, and height-for-age. Thinness and stunting are indications of undesirable environment, and of risk of poor development, ill-health, and death, with specific uses in situations ranging from crisis to chronic deprivation. The responses to crisis differ from those to long-term problems. So the relative important of assessing thinness vis-a-vis stunting depends on the circumstances and what is to be done.

Alternative measures of stunting and thinness are widely used. Weight-for-age, or growth measured by weight changes over time, is by far the commonest measure. Arm circumference is popular, for its apparent ease of measurement. These two are not precisely alternatives to height-for-age and weight-for-height; but they tend to correlate with these - weight-for-age with height-for-age; arm circumference with weight-for-height. They are useful as such, but less easy in interpretation, at least as at-one-time measures. Their utility also depends on severity. Their use as alternatives is referred to here, but not as primary measures.

Using anthropometry for screening individuals for attention, for targeting, and for assessing programme impact in populations, raises the question of whether success in response should be expected by the same anthropometric criteria. Generally, this would be so. Thin children, when fed, should gain weight. But in practice, there are complications, for several reasons.

One example is when only slightly thin children are selected into a programme - for example using a weight-for-height cut-off of 90% of standard. These children may have limited potential for weight gain, and evaluation on this basis may be disappointing. Although the children may well have benefitted in terms of increased physical activity, or they and their families from the income transfer in a food distribution programme, this may not be well assessed by weight gain.

A second possibility is that, for example, feeding thin children may be ineffective if the main cause of thinness is not food deficit. In most cases increasing dietary intake will in practice help considerably - even when for instance diarrhoea (see article in "News and Views"), malaria, or respiratory infections are the cause; in other cases, for example AIDS or tuberculosis, food may be of less use.

In older children especially, stunting may usefully identify individuals or populations needing intervention, but this may not change much the anthropometric measure, as stunting becomes partly irreversible. The benefits of feeding stunted children may be that activity and immunity (see figure 3) improve, even if the children are too old to regain lost height growth. Such children do not "respond" in terms of anthropometry, but benefit in other ways.

Different measures for different uses

Three distinctions define uses and appropriate measures: individual versus population assessment; whether measures are taken only at-one-time or repeatedly; and where the situation - individual or population - is in the range from crisis or emergency through to chronic deprivation, and the related decisions on intervention. Within these, the ages of children have an influence. The conclusions are described here under headings of: screening (individual assessment, measured at-one-time); growth monitoring (individual, over time); population survey (population level, at-one-time); and nutritional surveillance (population level, over time). Clearly anthropometric measures can be used for individual and then population assessments: screening can give situation assessment, with due regard to sampling issues; growth monitoring results can be aggregated for surveillance purposes.

Screening

Selecting individuals for admission to a programme - supplementary feeding is the main example used here - is called "screening". Anthropometry is widely used for nutrition and health programmes, partly because it provides direct, objective measures, often to supplement clinical judgement or as a screen that can be done by less-trained staff. Here again the appropriate measure depends on the use, in the range from crisis to chronic problems.

Emergency situations Acute food shortages, triggered by drought, floods or conflict, frequently lead to large numbers of people requiring assistance. Often resources are inadequate to fully deal with the numbers involved. How then to select those - particularly children - who most urgently need help? First, why are they selected?

In acute emergencies the primary need is to prevent deaths, then increased sickness, by food and medical attention. Under these circumstances, the thinnest children are the most at risk. Weight-for-height is the best measure. The next question is at what cut-off level of thinness - of deficit in weight-for-height - should it be decided that a child needs (for example) supplementary feeding, or intensive (therapeutic) feeding?

Hard and fast rules cannot be laid down (the meeting recommended) for all conditions. In principle, if resources - of food, medicines, personnel, and so on - are quite inadequate to cope with the influx of people, then the cut-off should be lowered to select the most severe cases. That's common sense, but difficult in practice in a crisis when frequently the numbers involved at the time - let alone what happens tomorrow - are not clearly known.

In this case, as well as when resources are less constrained and better organization is possible, conventional cut-offs defining "malnutrition" and associated mortality risk were considered to provide useful guidance. Cut-off levels put forward by WHO in 1978⁸:

- severe risk (defined as severe PEM) at less than 70% weight-for-height;
- moderate risk at 70% - 80% weight-for-height.

Severe risk (or PEM) requires very urgent attention, and probably intensive feeding. Moderate risk requires attention very soon - partly to avoid deterioration to severe - usually including supplementary feeding. The measures and criteria apply particularly to children under 5 years, but older children who appear wasted should be similarly screened.

In emergencies the equipment and trained personnel for weight and height measurement may be inadequate or non-existent. Arm circumference was considered a possible substitute, particularly when wasting is extensive. (Arm circumference measurement also requires some skill and time: the mid-point of the upper arm must be measured, the arm must be relaxed, the tape must just lie on the skin, not too tight or loose, arid so on. But it can be considerably quicker than weight and height.) Again, the conventional cut-offs (for under-5's) provide guidance (see note 8), as follows:

- severe risk at under 12.5 cm;
- moderate risk at 12.5 to 13.5 cm.

Non-emergency nutrition programmes Criteria for selecting children for regular nutrition programmes - for example, food supplements and nutrition education - differ somewhat from emergencies. The concern is less for immediate mortality risk, but for ill-health, reduced activity and development. Wasted children should still be included, but stunted children (who may not be wasted) may also benefit. Research shows that in the longer-term (over months or years), stunting is generally a better predictor of mortality risk than wasting in children aged less than 2-3 years¹⁰. Including stunting as a selection criterion in practise thus applies particularly to children under two.

The preferred anthropometric measures proposed for selection into nutrition programmes were thus:

- children under 2 years: admit those with low weight-for-height (thin, wasted) or low height-forage (stunted).

- children of 2 - 5 years: admit as priority those with low weight-for-height; if resources permit, stunted 2-5 year olds may also benefit. (They are likely to be continuing to have relatively low dietary intakes, which may be affecting at least activity and development - but note that this benefit may not be shown in reversing the stunting.)

A further issue is: what to do if height cannot be measured? Alternative screening criteria considered roughly equivalent to those given above were:

- children under 2 years: low weight-for-age (e.g. less than 80% of standard, or -2 S.D.'s)

- children 2-5 years: low arm circumference (e.g. less than 13.5 cm) or low weight-for-age (e.g. less than 80% of standard, or -2 S.D.'s).

The criteria proposed are thus to select households with children, both 0-2 and 2-5 years, with:

- low height-for-age (e.g. less than 90%, or -2 S.D.'s).

- low weight-for-age (e.g. less than 80%, or -2 S.D.'s).

Growth monitoring involves following changes in a child's weight on a growth chart. Growth charts are widely used for healthy children, under the normal circumstances of growing up, in both developed and developing countries. This early and continued use gives them a particular advantage for prevention. Thus, ideally all children should be regularly weighed and the results kept on growth charts. In practice, certainly all children enrolling in health and nutrition programmes should be issued with growth charts, and mothers motivated to ensure regular weighing - preferably every month but at least every three months. While priority is generally correctly given to children under five years, where resources and facilities exist it could well be valuable to continue growth monitoring through puberty; this would specially apply to young girls, where there is particular importance for ensuring as much growth as possible before puberty, to reduce inter-generational effects of small mothers having small babies - i.e. as a means of reducing low birth weight incidence in the long run.

Indications of growth faltering are useful for early detection of health and nutrition problems in children. But indications of growth failure alone are not readily related to specific causes, and often more information is needed to decide on the response. Growth monitoring also has the advantage of recording responses to intervention. In general, growth monitoring may provide for earlier detection of the need for intervention than screening measurements. Moreover, the trend measurement can distinguish children of adequate achieved size who are running into problems. Descriptions of growth monitoring methods are widely available¹¹.

The meeting, endorsing current practices in growth monitoring, drew attention to certain aspects requiring new focus.

The rapid changes in early life mean that interpretation of growth faltering - detected by serial weight measurements - depends heavily on the child's age. At the same time, criteria for defining when growth faltering is occurring, at different ages, have not been standardized, although a number of useful schemes exist. One set of criteria¹² is as follows:

- age zero to four months: gains of less than 0.5 kg. per month;

- age six to 15 months: three horizontal or falling monthly weights, even if they are within the "road to health" area (usually from -2 S.D.'s or 80% of median, to the median);

- age 16 to 60 months: three horizontal or falling monthly values below the "road to health" area; any loss of weight of more than one kg. in a month;

- any value found more than 2 kg. below the "road to health" area.

The use of growth monitoring extends beyond problem detection. It has been used to provide a basis for communicating with mothers and with health workers, concerning child health and nutrition, and to stimulate thinking about the causes of poor growth and malnutrition. This in turn has led to action at the level of the household and of the community itself. The meeting emphasized that the usefulness of growth monitoring depended on the weighing procedure never becoming an end in itself - the information must be understood and communicated, and action taken where indicated. Constant attention to this principle is essential. Then growth monitoring will come to be a cornerstone of individual child care.

One-time population assessment

Anthropometry readily indicates adverse conditions of environment and poverty, and shows risk of preventable suffering - death, ill-heath, and constrained individual activity and development. The use of anthropometry in surveys and surveillance (see later) capitalizes on both these functions, with varying emphasis depending on the decisions to be made. We can refer to these uses as proxies for environmental and socio-economic factors; and as indicators of future risk. (This is implicit in figure 3.)

Using anthropometry at population level introduces new considerations. To begin with, the concerns need to be defined, again ranging between crises for immediate intervention, and for long-term programmes. Very generally, as for individuals, wasting is the required measure in emergencies, and stunting for long-term problems. However, estimates of wasting and stunting can give very different answers: for example, prevalences of wasting and stunting in different population groups within a country usually show no correlation. Hence quite different priority rankings may be obtained using these different indicators - depending also on cut-offs used. This again emphasizes that we must distinguish situations of crisis from those of long-term deprivation, and make decisions accordingly.

Sampling is a central concern in population assessment, methods also depending on the uses of the information.

For population assessment, measurements need to be summarized. Thus the individual assessment turns into a proportion at risk, or prevalence. Generally, cut-offs chosen for population assessment are, logically, similar to those for individuals. But presentation of results becomes important, and other information may be included.

Assessment in emergencies The usual emergencies where malnutrition is of major concern are acute food shortages - circumstances similar to those discussed for the first screening use of anthropometry. The assessment is required generally to help answer such questions as: how severe is the food shortage? how many people are affected? who and where are they? The information may be needed to make urgent decisions on relief and on preventing further deterioration, as well as for assessing future needs.

First, it is obvious that anthropometry provides neither early indicators in a food crisis, nor by any means the only information required. Reports of drought, measures of crop failure, population movements, distress sales, and prices, are all examples of earlier relevant indicators. Anthropometry has a role in measuring human needs.

When the concern is hunger and starvation in an emergency, wasting or thinness should be assessed. Severe wasting is related to increased mortality, and results from inadequate food and disease.

Two issues arise here in interpreting the wasting. First, the cut-off to define wasting itself. Second, what the resulting prevalence means - including "trigger levels" for initiating action. The common practice, considered appropriate, is to use the indicator of:

- prevalence of less than 80% weight-for-height (or -2 S.D.'s) of under 5 children in a sample of the vulnerable population.

Interpretation of a prevalence of wasting - has it reached emergency level? - requires some knowledge of non-crisis conditions. Preferably, a prevalence level at which action will be "triggered" should be decided prior to a survey. No general level of wasting that indicates emergency can be specified. This depends too much on local circumstances. The meeting recommended that previous experience in emergencies should be compiled. Until this is done, if there is a lack of information, survey data compiled by WHO may provide guidance¹³, and some illustrations are given in box 2. These indicate, for example, 5-10% prevalence of wasting (here, less than 2 S.D.'s) in African countries in normal times - around 12% in Sahel countries; rising to substantially higher levels (e.g. 35-40%, Somalia, Sudan) in times of drought. But seasonal effects may be strong (see SCN News No. 4 pages 1-4) and must be considered.

Arm circumference is a possible alternative to weight-for-height in surveys to assess emergencies. Its predictive value for short-term mortality risk is less well-established, however; cut-off points and common prevalence levels below these are less well-known.

Selecting a sample for population assessment in emergencies may be especially difficult. Constraints of time, migrant populations, remoteness, and others, militate against rigorous sampling procedures. Attempts should be made to use some kind of sampling frame such as lists of villages, with population estimates. Usually deliberate sampling of areas or people most likely to be affected will be appropriate, but it is important to have some idea of the populations to which the results refer. Use of even rough population data to select a sample (or sample sites) is better than haphazard selection. In presentation of results, some judgement as to whom the data refer to has to be made.

Assessment for long-term planning Inserting nutrition considerations in planning - for economic development, for agriculture, for health and other social sectors - requires data some of which can be provided by anthropometry. Here especially, anthropometric measurements may be useful both as proxy measurements of poverty and poor environment - themselves causes of malnutrition - and as indicators of risk of mortality, ill health and constrained child development - as human outcomes central to planning for socio-economic development.

Causes of growth failure are age-dependent. For example, where the concern is mortality risk of young children, the age group of priority would be from birth to two years, and the interventions would be aimed at mothers, infants and young children. In looking at the relationship between weaning practices and early growth faltering the key period is from 6-24 months. For more general economic planning, development of health services, etc., a wider age range may be selected, for example 0-60 months.

BOX 2

Illustration of wasting prevalences (% <-2 SDs weight-for-height)

Country	Prev. %	Country	Prev. %	Country	Prev. %
Botswana	6	Burkina Faso	12	Bangladesh	16
Burundi	6	Mali	11	Burma	11
Ethiopia	12	Niger (Drought)	23	India (Tamil Nadu)	21
Kenya	5			Thailand	6
Lesotho	5	Cameroon	2
Malawi	3	Congo	5	Ecuador	2
Somalia (Drought)	40	Cote d'Ivoire	9	Peru	1
Sudan (Drought)	36	Ghana	7
Tanzania	5	Nigeria (Drought)	21
Uganda	4	Senegal	6
		Zaire	5

Source: taken from WHO (1989), "Global Nutritional Status, Update 1989"; results are to illustrate common prevalences of wasting, generally in 6 to 60 month old children in 1980's.

- height-for-age, with the age-group depending on the specific issue as discussed above; for presentation, prevalences may be used, conventionally below 90% of reference or less than 2 S.D.'s; for examining associations with causal factors, the actual percentage of standard or Z-score (deficit in height as proportion of standard deviation of references at that age) is more often used, as a continuous variable.

As an indicator of potential problems in the first year of life, birth weight is clearly important. (Birth length may in fact be better than birth weight as a proxy for perinatal and neonatal risk.) The usual problem with birth weight (or length) is availability and representativeness. Should coverage be less than say 60%, then its reliability must be suspect.

Adult anthropometry is becoming more widely used. Hitherto, mothers' weight gain during pregnancy has been the commonest measure, for individual assessment. Now, with concern for women's nutrition, as well as for adult men, measures such as "Body Mass Index" (BMI), calculated as weight (in kg) divided by height (in metres) squared, are coming into use. The meeting noted that cut-offs had been suggested for BMI of 18.5 - above which chronic dietary energy deficiency is unlikely; 16.0, below which chronic energy deficiency is very likely; and in the range of 16.0 to 18.5, further information on diet is needed¹⁴. (These values do not apply to pregnant women.)

Sampling methods for surveys for these purposes can often - and certainly should - be rigorous. Time devoted to correct sampling procedures will be well-spent, because use of results frequently depends on clearly attributing them to specific population groups, and on assessing credibly differences between these - often to specify who is most affected.

In practice, one-time surveys have most often proved useful for this purpose - showing which groups are most affected. Categories like administrative area and by urban or rural location have been important, for targeting and analysis. Other socio-economic breakdowns have proved informative: land-holding area, education level, housing and sanitation, and access to services are examples of associations commonly found. Generally prevalences of stunting or underweight by such categorization have been the main findings of large-scale - often national - surveys; for example, in the "functional classification" approach¹⁵. More complex multiple associations have been demonstrated particularly in intensive more focussed surveys.

An emerging analytical method is worth noting, where rather than cut-offs to define prevalences the overall distribution of results - say height-for-age Z-scores - is compared with the distribution in the reference population¹⁶. The area falling between the observed and the reference is then regarded as the excess prevalence of growth retardation. A striking example from a recent large survey in Brazil is shown in Fig. 4. Advantages include doing away with the need to define a single arbitrary cut-off, and sharpening differences between groups.

Nutritional surveillance

Surveillance systems - in public health, nutrition, or other subjects - link information with action, often pre-defined. For example, reports of cholera led to swift measures to immunize, deal with water and sanitation, and provide emergency treatment. Nutritional surveillance uses anthropometry in different ways depending on the problem and reaction - uses yet again distinguishable in the range from crisis and emergency to long-term development. A common feature of surveillance is that data are available repeatedly over time. A few resulting principles can be quickly put forward.

The timing of the information is critical to the response. This affects the indicators chosen.

Figure 4. Distribution of height-for-age of 0-10 year-olds by tercile (third) of income groups, Brazil, 1989.

Source: Pesquisa Nacional sobre Saude e Nutricao. Resultados Preliminares. INAN, Brazil, March 1990. (Kindly provided by Dr C. A. Monteiro, FSP/USP).

The varied uses of anthropometry can be considered - as at the meeting - under conventional headings from timely warning to long-term planning¹⁷.

Timely warning Response to acute food shortages early enough to prevent hunger and malnutrition is one aim of "early warning systems"; the designation "timely" is used in this context to stress that the information must be "early enough": that indicators relate to response. Increases in prevalences of wasting (for example) are precisely one of the outcomes the warning is meant to prevent. Hence the two main uses of anthropometry in timely warning are, first, to give a basis, by analysis of past events, for selecting effective early indicators - from rainfall, agricultural, or economic data, for example. And second, to provide a rapid if rough "fail-safe" current monitoring of nutritional conditions, for targeting and urgent additional response to needs.

In both cases, the anthropometric measure most relevant is wasting in the vulnerable population - as discussed for emergencies under "screening" and "one-time assessment". There is an important practical proviso, since trends are monitored. Rapid changes in weight-for-age in the population, usually detected as prevalences of underweight (e.g. less than 80% or 2 S.D.'s of reference) are likely to be due to wasting, not stunting. This means that the commonest anthropometric data, from weight measurements in clinics (for individual assessment and growth monitoring) can be used for this purpose: a rapid increase in proportion of underweight children may be a legitimate sign that food shortage is causing wasting.

Historical time series of changes in underweight (or other variables,) have been used effectively to select and validate early indicators. Not only the measure - e.g. crop conditions - but the cut-off points and warning levels - can be analyzed, with respect to what actually happened. Examples from Botswana and Indonesia demonstrate this¹⁸. More recently, steep rises in food prices have been shown to precede increases in underweight or wasting prevalences in a number of African countries in times of drought and economic stress¹⁹. The example of Ghana was shown in SCN News No. 4, pages 2-3. Food price based indicators may become increasingly important, also for monitoring effects of structural adjustment and compensating for short-run consumption effects on vulnerable groups²⁰.

For "real-time" monitoring within a timely warning system wasting is usually the condition of concern and weight-for-height is the appropriate index. Weight-for-age is a serviceable substitute and is most widely used at present. Reporting will be in terms of trends in prevalences based on weight-for-height (preferably), or weight-for-age. As noted, rapid changes in weight-for-age will be due to changes in wasting. Arm circumference, which can be considered for screening in emergencies, may be an adequate substitute for weight-for-height for estimating prevalences of wasting-Data are usually presented as trends in prevalences below the cut-off point. In this case, trigger levels for intervention may be related to changes in prevalence, not to absolute levels of prevalence itself, and therefore the choice of cut-off point is not critical but must be used consistently. Typically this will be -2 S.D.'s below the median using either internal or external references. No universal criteria for judging the rate and scale of prevalence change can be offered; local experience based on previous nutritional emergencies can provide guidance.

For long-term planning and programme management For these purposes longer-term trends in anthropometry are of interest, because the action generally is establishing and managing programmes, and/or policies for economic and service development. Trends in height-for-age or weight-for-age indices, by population group, are usually appropriate. Height-for-age (in particular) is the index most closely related to economic and environmental factors (albeit lagged), that development policies and specific programmes are to improve.

Height-for-age is also the better anthropometric predictor of mortality for young children in the longer-term (months or years), and growth performance thus measured correlates best with other aspects of child welfare (shown in figures 2 and 3), including individual development.

Viewed over months and years, trends in child height (and weight) give useful focus on progress or deterioration, for the national population and for groups within this. Many examples are given in the SCN's Update report²¹, some of which were quoted in SCN News No. 4. Comparing across countries, we can get a better sense of what is happening from such data; more so within countries.

The population to be measured again depends upon whether, for example, specific interventions or more general inputs to development are intended. The latter circumstance implies a need for broadly based, representative samples, covering such groups as preschool children, school entrants, and adults. It is vital that samples are comparable over time if trends are to be assessed.

Accounting for observed trends is the next step, preferably linked to targeting. Accounting for possible causes may be difficult analytically. One specific case where linkage to inputs and related decisions is relatively straightforward is within programmes with clear nutritional objectives.

As described in SCN News No. 4 (pages 14-16) quite a number of large-scale long-standing nutrition programmes now exist. Many of these anyway collect anthropometric data (most often, weight-for-age), as part of regular activities - for selecting participants for example. These results can be used both to track overall progress - including for evaluation - and to guide activities - for targeting, say. Results we quote in the "Update" report (page 99) from a project in Iringa, Tanzania, provide an example. Here, trends in underweight were estimated to have fallen during - and probably as a result of- project activities. These data were used within the project, for selecting and targeting, and as experience accumulated, to prepare for extension.

Different examples come from Central America, where school surveys - of height-for-age of school entrants - have been repeated over the years, to track trends and give information for new programme activities.

The meeting essentially endorsed such current uses of anthropometry for long-term surveillance. The need now is to continue application, as a basis to producing more effective and sustained support for combatting malnutrition.

-J.B.M.

Participants in the ACC/SCN workshops on 12-14 June 1989 were: G. Beaton, W. Bertrand, F. Falkner, P. Greaves, J-P. Habicht, A. Kelly, J. Kevany (Chairman), M. Lotfi, R. Martorell, J. Mason, A. Pradilla, F. Trowbridge, J. Waterlow, R. Weisell. Extensive comments and suggestions for this article from R. Martorell are gratefully acknowledged.

NOTES

(1) FAO, Fourth World Food Survey, p 30, FAO, Rome, 1977.

(2) Summary of Current Country Activities in Nutritional Surveillance, A. Kelly, ACC/SCN 16th Session paper (90/N Svl), 1990; plus internal update March 1990.

(3) UNICEF, State of the World's Children, 1982-3, 1984, UNICEF, New York.

(4) FAO, Fourth World Food Survey, footnote 1, p 29; FAO, Rome, 1977.

(5) ACC/SCN, Report of 15th Session (Feb 1989); paras 19-21, ACC/SCN, Geneva, 1989.

(6) Appropriate Uses of Anthropometric Indices in Children, A report based on an ACC/SCN Workshop, 1989, ACC/SCN, Geneva - forthcoming.

(7) SCN News No. 4, p 7; Malnutrition and Infection: A Review, ACC/SCN State-of-the-Art Series, Nutrition Policy Discussion Paper No. 5, by Andrew Tomkins and Fiona Watson, ACC/SCN, Geneva, 1989.

(8) The Management of Nutritional Emergencies in Large Populations, de Ville de Goyet, C., Seaman, J., Geijer, U., WHO, Geneva, 1978.

(9) Assisting in Emergencies: A Resource Handbook for UNICEF Field Staff, UNICEF, New York, 1986.

(10) Bairagi, Radheshyan, Mridul K. Chowdhury, Young J. Kim and George, T. Curlin, 1985 Alternative Anthropometric Indicators of Mortality, American Journal of Clinical Nutrition, 42: 296-306.

(11) Lotfi (1988), Growth Monitoring: A brief literature review of current knowledge, Food and Nutrition Bulletin, vol. 10, No. 4, p 3-10; Yee and Zerfas, 1987 Issues in Growth Monitoring and Promotion, LTS/International Nutrition Unit, In: Growth Monitoring Information Packet, Washington DC: American Public Health Association, Clearing House on Infant Feeding and Maternal Nutrition, 1987, and special edition of the Indian Journal of Pediatrics (Vol. 55, No. 1, 1988)

(12) Stevany, J. (1982) Standardized Interpretation of Under Fives Weight Curves, Tropical Doctor 12, 133-135.

(13) WHO Global Nutritional Status, Anthropometric Indicators, 1987; WHO Global Nutritional Status, Anthropometric Indicators, Update, 1989, WHO Weekly Epidemiological Record, Part I, No. 7, 1987, pp 37-38; Part II, No. 8, 1987, pp.45-50; Part III, No. 9,1987, pp.57-59. Part IV, No. 10,1987, pp.64-6; Part V, No. 11, 1987, pp.71-73; Part VI, No. 12, 1987, pp.78-80.

(14) Definition of Chronic Energy Deficiency in Adults, Report of a Working Party of the International Dietary Energy Consultative Group, W.P.T. James, Anna Ferro-Luzzi and J.C. Waterlow, European Journal of Clinical Nutrition (1988) 42, 969-981.

(15) Food and Nutrition Planning, Joy, J.L. & Payne, P.R., FAO, Rome, 1975 (FAO Nutrition Consultants Reports Series, No. 35).

(16) Mora, J.O., A New Method for Estimating a Standardized Prevalence of Child Malnutrition from Anthropometric Indicators, Bulletin of the World Health Organization, 67, (2): 133-142 (1988). 245

(17) Nutritional Surveillance, J.B. Mason, J.-P. Habicht, H. Tabatabai, V. Valverde, WHO, 1984.

(18) (a) Timely Warning and Intervention Systems for Preventing Food Crises in Indonesia, Brooks, R.M., J.-P. Habicht, D.F. Williamson, Food and Nutrition (FAO), 11 (2), 37-43, FAO, Rome
(b) Brooks et al Cornell University Press (forthcoming).
(c) Using Agricultural Data for Timely Warning to Prevent the Effects of Drought on Child Nutrition in Botswana, J.B. Mason, J.G. Haaga, Tshire O. Maribe, G. Marks, Victoria J. Quinn & Karen E. Test, Ecology of Food and Nutrition, Vol 19, pp. 169-184,1987.

(19) ACC/SCN, 16th Session documents: Economic Indicators of Access to Food and Nutritional Status, Hamid Tabatabai, ILO, SCN 90 Str Adj B, 1989; Forecasting the Prevalence of Underweight Children, Alan Kelly, ACC/SCN, SCN 90 Str Adj C, 1989.

(20) ACC/SCN, 16th Session document: Suggested Approaches for Nutritional Surveillance with Particular Reference to Structural Adjustment, SCN 90 Str Adj A, 1989.

(21) Update on the Nutrition Situation, recent trends in nutrition in 33 countries, ACC/SCN, 1989.

Malnutrition and Infection (part II)

Operational implications of current knowledge on nutrition and respiratory tract infections, malaria, and intestinal parasites.

Respiratory Tract Infections and Malnutrition

Respiratory infections have been implicated in growth faltering, although there is as yet limited information on the mechanisms involved. Nevertheless, anorexia, fever, pain, vomiting (especially in pertussis) and associated diarrhoea, may all be important contributory factors. Recommendations in relation to diarrhoea largely apply also in the case of acute respiratory infections: sustained breastfeeding and nutritional supplementation. There is accumulating evidence that vitamin A deficiency increases risk of developing respiratory disease; and that children who are vitamin A deficient are more likely to suffer from chronic ear infections.

Programmes to prevent and improve the management of acute respiratory infections are giving increased attention to pneumonia especially in young children, as the most serious illness with the highest mortality risk. Pneumonia is of higher incidence in developing countries than in the industrialized world, and is a major cause of death.

Malnutrition is considered a key risk factor for pneumonia, and maintaining good nutritional status is thus important in preventing infection. Children with poor nutritional status - as measured by growth - and of low birth weight merit priority for particular attention when presenting with respiratory infections. Breastfeeding is considered to protect against respiratory infections - as for other diseases - and should be strongly promoted. As well as vitamin A, other micronutrient deficiencies, notably zinc, and iron (and possibly vitamin D) have been implicated in acute respiratory infections, probably through effects on the immune system.

Adequate feeding is essential during management of acute respiratory infections, and requires emphasis. This applies, as for other illnesses, to continued breastfeeding of infants and young children, and provision of suitable weaning foods. It is expected that administration of vitamin A contributes to reduced severity in general, and that it lowers case-fatality in pneumonia.

Malaria and Iron Deficiency

Programmatic responses to the interactions between iron status and malaria need careful consideration. Iron deficiency depresses the immune response, increasing susceptibility to infection. However, the malaria parasite requires iron for its multiplication in blood, and thus may be less infective in the iron-deficient individual. Malaria causes haemolysis, which in turn causes anemia.

Preventive measures for malaria and anemia are thus often related, but each with its own considerations. For example, malaria chemoprophylaxis for young children on a population basis is not recommended for several reasons, including interference with the development of protective immunity to malaria, and possible acceleration of drug resistance.

One issue concerns iron supplementation with malaria chemoprophylaxis programmes. In general, iron (preferably with folate) should be administered to all pregnant women who are receiving malaria chemoprophylaxis in malaria endemic areas.

Iron supplementation programmes in the population as a whole are important to prevent anemia, particularly in women and young children. An issue that arises with general iron supplementation in malaria endemic areas concerns whether this should be done if malaria chemoprophylaxis cannot be administered at the same time. It is expected that the net effect of iron supplementation under these conditions would be a decrease in malaria, due to the immune effect. However, research into this issue, and monitoring of morbidity in a supplemented population, is urgently needed. In the interim, the recommendation is to proceed with oral iron supplementation, at the same time as malaria prophylaxis by itself, and monitor rates of infection.

In treatment of malaria, correcting iron-deficiency anemia is frequently indicated. Current evidence is that administration of iron by intra-muscular or intravenous injection is to be avoided, as it risks exacerbating the malarial (or other) infection. Oral administration of iron, in moderate doses (for example, 60-120 mg ferrous sulphate), is recommended, the benefits outweighing the risks.

Equally treatment of anemia, both in malaria-endemic areas and for individuals (particularly when underweight) in other contaminated environments where infections are prevalent, should use oral iron, in moderate doses.

Intestinal Parasites and Nutrition

Intestinal parasites* may be associated with a reduction in food intake, malabsorption, endogenous nutrient loss, and anemia. Behavioural effects of parasitic infestation may also be important: the blindness resulting from onchocerciasis may lead to malnutrition; discomfort and anorexia may also affect food intake. While it is clear that parasites may lead to malnutrition, the extent to which malnutrition itself causes increased parasite infestation is not clearly known. Nonetheless, the two conditions so frequently co-exist, and the potential for reinforcing programmes is so clear, that they frequently need to be considered together. While improvements in environmental sanitation are essential for long-term prevention of infection by intestinal parasites, programmes of regular treatment of vulnerable populations with anthelmintics are widely used.

*i.e. Ascaris, hookworm, and Trichuris as well as intestinal and urinary schistosomiasis.

Iron deficiency anemia is well known to be associated with hook worm infestation, and public health measures to deal with hook worm should routinely include iron supplementation. Similar considerations may apply for other intestinal parasites.

Cases of severe protein-energy malnutrition are frequently also suffering from intestinal parasite infestation, which should therefore be treated as part of nutritional rehabilitation. Giardia lamblia is often associated with severe malnutrition in certain areas, and may merit particular attention.

AIDS and Malnutrition

As noted by the SCN 14th Session (1988) the association of AIDS with malnutrition may indicate a useful role for diet during the disease. Unknown at present is whether nutritional deficiency has any effect in predisposing either to attack by HIV, or to progression from infection to the disease. Other factors in HIV infection are no doubt more important than nutritional ones, and research designs would not be simple. Nonetheless, this is a possible research area.

-J.B.M.

Additional material:

WHO (1981). Field Studies on the Relation Between Intestinal Parasitic Infections and Human Nutrition. Report of an Informal WHO/UNICEF Consultation, Geneva, 5-8 May 1981. World Health Organization, Geneva.

Stephenson Lani S. and Celia Holland (1987). The Impact of Helminth Infections on Human Nutrition. Schistosomes and soil-transmitted helminths. Taylor & Francis Ltd, London, England.

Estimation of Flows of External Resources in relation to Nutrition

Preliminary result from SCN study.

Figure 1. Aid for health and education.

The chart below shows that aid for nutrition, health, and education is a small and diminishing part of the total aid effort.

Source: UNICEF. "The State of the World's Children, 1990". New York, Oxford University Press, 1990. (Adapted from: Development Co-operation Reports, OECD, Paris)

A prior step to re-allocating and increasing resources to reduce hunger and malnutrition is to assess resources globally, and comprehensively, that deal with nutrition problems, in relation to numbers and distribution of those affected. This has been a longstanding concern of the ACC/SCN. Here we give a preliminary report on recent research carried out by the SCN, based on a paper written for the SCN 16th session (and subsequently updated)³. Details will, we hope, be published later this year.

Beginning with reports on the world nutrition situation and a review of nutrition policies, the ACC/SCN is now completing an assessment of resource flows. These activities, which are clearly related to each other, will be used to look at the evolution of nutrition problems, the resources available to deal with them, and the best way to use these resources.

In order to arrive at a global estimate of the flow of external resources in relation to nutrition, all multilateral and bilateral activities must be accounted for and classified by their relevance to nutrition. ACC/SCN has recently carried out this process with the help of three databases consisting of: 1) development activities of the United Nations System compiled by the U.N. Advisory Committee for the Coordination of Information Systems (ACCIS); 2) bilateral activities of the DAC countries compiled by the Organization for Economic Co-Operation and Development (OECD); and 3) projects funded by the World Bank.

ACC/SCN Database

The ACC/SCN database which was compiled from the three existing databases consists of approximately 30,000 development projects for 1987: 22,757 U.N., 6,076 bilateral, and 1,776 World Bank. For each project or activity, the database contains information on: project title; descriptors; and financial information including grants, loans, credits, and expenditures.

The procedure essentially has been to try to list all externally-assisted projects in the world (on public funds; multilateral and bilateral; technical cooperation, grant and loan) in 1987, and code them according to a classification system based on relevance to nutrition. This database then led to numerous tables and charts describing the distribution of resource flows by development sector and geographic region.

Limitations of the data

Before proceeding with some of the results, the limitations of the data need to be considered. First, there are still possible gaps. The database deals with public flows - Official Development Assistance (ODA) - which are estimates of gross flows from donors to developing countries. Private flows - that is mainly private banks, but also NGO's - are not included. OECD estimates that for 1987 private flows totaled $26,478 million accounting for approximately 38% of total net flows. In addition, it is not clear whether full estimates of resources from Regional Development Banks are included in the database which should amount to about 2% of total net flows. Activities carried out by UNHCR have also not been included because they were not reported to ACCIS. A second difficulty is that multilateral and bilateral flows are reported in quite different ways. Multilateral flows (i.e. ACCIS and World Bank data) are intended to give actual disbursements during the year, and in principle are addable. Bilateral figures are reported as commitments made in 1987, of generally multi-year grants or loans, not as flows. However, commitment data for years prior to and after 1987 reveal that the figures for 1987 may be considered as broadly comparable with gross disbursements because there is an ongoing balancing process. Although the use of commitment figures should not unduly affect the total estimates of flows, the number of on-going bilateral projects operational in 1987 will be substantially underreported. This affects the related inventory of projects which SCN is also working on, but has less effect on estimates of aggregated financial flows. Finally, for the direct nutrition category, only nutrition projects are identified, not components within either projects which will be scored under the main project type. This leads to some underestimation in the direct nutrition category.

Results

The total of Official Development Assistance for 1987 is estimated as about $45 billion. This is equivalent to about $12 per caput of the population of developing countries. Figure 2 shows the distribution of the use of funds in the first chart and the distribution by U.N. agency and bilateral donor in the second. The area of each subdivision is proportional to the funds in the category, so that a visual comparison of area is intended to give an image of the amount of funds in the category. The system used to classify the projects has 12 categories; Direct Nutrition, Food Aid, Emergency Food Aid, Health, Family Planning, Water and Sanitation, Other Food, Child Welfare, Literacy and Women, Community Development, Emergency Assistance and Rehabilitation, and "Indirect" which includes all other general development activities, and is the largest category.

Figure 2 (a). Distribution of total external resources (1987) by nutrition-related category and source

Figure 2 (b). Distribution of total external resources (1987) by funding source

Source: "Estimate of Flows of External Resources in relation to Nutrition". Draft 1. 4/4/90. Paula W. Yoon and John B. Mason. ACC/SCN, Geneva.

Figure 3. Display of estimates of per caput flows of total external resources (1987) by region

Areas of charts are proportional to $ per caput - charts drawn to the same scale

Table 1 1987 Official Development Assistance (ODA) per caput of population of developing countries

Region	ODA per caput	ODA for nutrition per caput	ODA for food aid per caput
Sub-Saharan Africa	$21.8	$0.044	$1.4
Mid America & Caribbean	$33.2	$0.036	$2.2
South America	$15.1	$0.017	$0.42
South Asia	$6.7	$0.005	$0.38
Near East & North Africa	$29.8	$0.001	$0.66
Southeast Asia & China	$6.8	$0.014	$0.09
Global	$12.2	$0.019	$0.49

For direct nutrition projects and for food aid, it is easier to grasp per caput figures when the population used is that estimated to be malnourished, rather than the total population. The best estimate available for this was for malnourished children, which may be not too bad as many nutrition projects are targeted at children. The estimates for multi-and bilateral funds by region for $ per malnourished child are shown below in Table 2.

Table 2 Official Development Assistance (ODA) for Nutrition and Food Aid Per Malnourished Child

Region	ODA for nutrition per malnour. child	ODA for food aid per malnour. child
Sub-Saharan Africa	$0.93	$33.3
Mid America & Caribbean	$2.71	$180
South America	$1.96	$50.0
South Asia	$0.05	$4.25
Near East & North Africa	$0.10	$43.6
Southeast Asia & China	$0.60	$3.88

Notes:	1) Prevalence malnourished taken from the SCN supplement on the "First Report on the World Nutrition Situation".
	2) Food aid includes emergency and non-emergency food aid.

Does the current level of resources make a difference?

One yardstick for assessing whether the external resources estimated to be available are within orders-of-magnitude of being likely to contribute to improvement of nutrition on a wide scale is to consider recent experience in nutrition programmes, and their associated expenditures. An important proviso is that external resources have varying roles depending on local circumstances: in poorer countries, they may amount to significant proportions of government budgets, and be directly used for providing goods and services; in other cases - in many Asian countries for example - they are less significant overall, and tend to be used more catalytically, for planning and technical cooperation purposes, for example.

A number of examples now exist of operational programmes, as for instance discussed at the SCN symposium in Korea in August 1989; projects in Botswana, Costa Rica, Indonesia, Iringa (Tanzania), Tamil Nadu (India), Thailand, and many others are beginning to show some consistency in effects. These experiences may give some rough guidance. Broadly, it seems that around $5 per recipient per year is the sort of level of non-food expenditure associated with reported impact; and in the range of $10 - $50 per recipient per year for food-related expenditures. These are not usually distinguished between external and internal resources, and this needs further work; the impression is, as expected, that in higher income countries these is a greater proportion of internal resources. Thus we are at present only able to compare overall expenditures at project level with external resource availabilities. Nonetheless, on this basis, it might be considered that somewhat less than 10% of the necessary non-food resources, if targeted to malnourished children, was available; and that food aid resources may be relatively slightly less constrained.

Another way of viewing the results is to consider total numbers. Approximately 160 million children were estimated to be underweight in 1984; $5 per head is $800 million, $50 per head is $8 billion. Total "direct nutrition" resources are estimated at $71 million - less than 10% of need. Alternatively, $71 million could perhaps have an impact on 10 million or so children. The prevalence of severe malnutrition is clearly much less than "underweight" (less than 2 SDs of NCHS standards); it is conceivable that this sum might make a significant impact if it could be targeted very specifically to severe cases only.

Overall, now that we have some idea as to the funding position, the usual options for deciding what to do under circumstances of inadequate resources may be considered in this context. These clearly encompass better use, including targeting, of the resources available. Increasing the resources can mean reallocation from other uses, and increasing the overall size of the pie - of total funding allocations. In public health doctrine, when resources are inadequate the criteria for intervention may be made more stringent until only the number that can be adequately dealt with are admitted into the programme; the analogy here would again be with targeting, by location based on need, and by more stringent screening.

Finally, when the resource availabilities not only for nutrition but for other related activities - for example health care and water and sanitation - are viewed, resources might not look quite so constrained if coordination in practice could be achieved. This might be worth exploring soon.

- Paula Youn & John Mason

NOTES

(1) "Development Co-Operation: 1988 Report", OECD, Paris, 1988.

(2) From "Action by Developed Countries to Assist Developing Countries in Their Fight Against Hunger" World Food Council, WFC/1990/4, 6 April 1990.

(3) Estimate of flows of external resources in relation to nutrition. Draft 2, 4/4/90. Paula W. Yoon and John B. Mason. ACC/SCN, Geneva.