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EMERGING PRIORITIES FOR THE NUTRITIONAL SCIENCES
J. C. Waterlow
There will be no nutritional science, and hence no
useful discussion of priorities, unless there is a
continuing flow of young people into the study of the
subject. What challenges face them? They will find a
degree of polarization among people working in nutrition
(Waterlow, 1981~. It is a commonplace that malnutrition
results from poverty. Here are two quotations from the
same number of the United Nations University (UNU) Food
and Nutrition Bulletin:
On . . . the use of external bilateral and
multilateral instruments to build a global economic
order of significantly greater equity (within as well
as among countries), I am rather pessimistic, at
least as far into the next 15 to 20 years as I can
see (Joseph, 1985~.
It Is realistic to contemplate the elimination
of hunger and malnutrition if and when governments
adopt social, economic, agricultural, educational,
and health policies that have enabled countries with
a wide range of political systems to achieve this
goal in a surprisingly short time. . . . The
encouragement and assistance that international,
bilateral, and voluntary agencies can provide will
make a critical difference (Scrimshaw, 1985~.
We note in passing that Scrimshaw did not include
nutrition in his list.
Those statements and reflections were presumably
addressed to governments and other organizations.
However, at the end of the road, whatever is achieved
depends on people. What should a young person do who
wants to make a contribution? Grant told us at the
International Congress of Nutrition in San Diego 4 years
ago that we have to stimulate political will. That
advice was, I suppose, given to us as citizens, not as
nutritionists. In this climate of opinion, many people
feel that their best contribution is through the social
sciences, management, administration, and so forth.
It is not unnatural that the biomedical scientists
should feel on the defensive. What can we contribute,
other than to act as a conscience for governments, as
43
-
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44
Gopalan of India put it at the World Health Assembly some
years ago. If the biomedical scientists are on the
defensive, it is partly our own fault. In the United
States and United Kingdom, nutritional science has gained
much of its strength from animal husbandry, as is obvious
if we look at the institutions in these countries and the
traditional nutritional journals. I do not think it
would be unfair to say that perhaps the greater part of
scientific output in nutrition is irrelevant to Third
World problems. That is natural enough, as long as most
~ ~ ~ _ ~ ~ 1 __ _ ~ ~
nutritional science Is done In developed countries.
It might be supposed that the way to build a bridge
between the social and biomedical components of nutrition
is by multidisciplinary discussions, as in this sympo-
sium. However, I like very much a phrase in Galbraith's
autobiography: ''Discussion is a vacuum designed to fill a
vacuum" (Galbraith, 1982~. We get a smattering of each
other's point of view, but that is no substitute for a
proper basic training. Richard Jolly, in his address at
the last International Congress of Nutrition (in press),
spoke of the importance that Barbara Ward attached to
professionalism.
I fully agree. There is no subject in
which professionalism is more needed than in nutrition.
In what other subject would you find that, of all the
professors and writers, including me, so few have had any
basic training in what they profess? In what university,
for example, can one find a proper degree course in
developmental nutrition--equivalent, say, to a degree in
agricultural economics? I will not enlarge further on
. . .
tne SUbJ ect or training, except to say that, if I had
control of a great deal of money, I would give priority
to establishing such university departments in Third
World countries or strengthening them where they exist.
It is sad that national and international agencies, with
few exceptions, seem to find great difficulty in pro-
viding long-term institutional support in developing
countries (United Nations University, 1984~. At the same
time, we all say that a major bottleneck in long-term
measures for the prevention of famine is the lack of
local infrastructure and technical know-how. Is there
not some hypocrisy here?
Let me now come somewhat closer to my title:
priorities for nutritional sciences. In defining
priorities, the scientist needs some guidance from
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45
policy-makers and planners on the general framework
within which he is to operate. Is the aim of policy to
improve the nutritional state of virtually the whole
population in poor countries? Or is it to eliminate the
severe cases? I have not seen the distinction thoroughly
discussed in relation to nutrition and malnutrition, and
certainly not with the passion that surrounds the contro-
versy over high blood pressure--whether to try to shift
the distribution of blood pressure in the population as a
whole or to concentrate resources on those who are
clearly at risk.
For nutrition, the two policies can be promoted
together, and they are coming closer together. The
''trickle-down" approach through overall economic
development seems to be losing ground in favor of the
"basic-needs" approach (Streeten et al., 1981) or
''development with a human face" (Jolly, in press). The
emphasis has changed over the years; there is now much
talk of community participation and of increasing the
social mobility of women (Joseph, 1985~. Be that as it
may, such policies are largely in the province of social
scientists, economists, and politicians.
The second approach--what Streeten et al. (1981),
using a military analogy, called "precision bombing"--
lies squarely in the province of the health sector. Such
a strategy might well be unpopular in the present cli-
mate, because it goes against the principle of prevention
for all and is reminiscent of the out-of-fashion hospital
approach. Nevertheless, opinion does seem to be moving
in that direction, as judged by a recent World Bank paper
(Lipton, 1983~. The practical difficulties are enormous,
but I believe that they can be overcome through the
primary health care system, if it is properly geared to
that strategy. Moreover, I think that such a strategy
will have a "trickle-up" effect. Is it not the case
that, whatever the causal mechanism, birth rates tend to
decrease as infant mortality falls?
I referred to "severe cases," and it is precisely the
problem of defining "severe" that should indicate the
priority for nutritional sciences in the next decade.
The difficulty, of course, is that nutritional status is
a continuous variable, so it is artificial to draw a line
between those who should and those who should not be
called severely malnourished. Nevertheless, in real life
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46
it has to be done. The analogy with blood pressure
applies here also: the doctor, confronted with this
continuous variable, has to decide on the level that
warrants treatment. In Britain, we have just finished a
very large trial of the effects of lowering the cutoff
point of blood pressure for antihypertension treatment:
It appears that the gains are small in relation to the
enormous cost of hypotensive drugs. Thus, the choice of
where to place the cutoff point depends on two things:
biological knowledge (how the risks vary in degree and
kind as one moves down the ladder of worsening nutri-
tional state) and practical considerations (such as the
size of the group at risk, how it can be reached, and the
resources needed to deal with it).
For nutritional research on all problems, the same
general question applies: how best to match resources and
results. However, the different problems are in differ-
ent stages of development. In the case of vitamin A
deficiency, iodine deficiency diseases, and anemia, there
is a great body of knowledge, although, of course, it is
never complete and there have been some exciting scien-
tific developments in recent years. Interest in these
conditions is high, and we have the technology for pre-
vention. I judge that it is largely a matter of
resources and sometimes of political will. It is
remarkable, for example, that in southern Germany 30%
of women still have goiter (Elton, 1978~. Scientific
knowledge of other conditions is more or less in its
infancy, and we do not even know how important they are.
Examples are trace-element deficiencies and the effects
of mycotoxins. There is also protein-energy malnutri-
tion. The magnitude of the problem of malnutrition is
enormous; there is a great deal of knowledge, but it has
serious gaps. Until those gaps are filled, we cannot
have a rational policy for prevention.
I shall now discuss three examples of gaps in our
knowledge on the effects of energy and protein deficiency
that I think should have a high priority for nutritional
science in the next decade. Protein takes second place
to energy, because, as is widely accepted, an intake that
provides enough energy will usually supply enough
protein. There are important exceptions, but those
concerned with policy, such as the Food and Agriculture
Organization (FAG) and the World Bank, are surely right
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47
to concentrate first on energy intake. The three
subjects deserving priority are body size, adaptation,
and resistance to infection.
BODY SIZE
.
The best way of coping with a deficit in energy
intake, is to be small. But how small? To normalize for
differences in height in adults, it is convenient to use
the body mass index (BMI): weight (in kilograms) divided
by the square of height (in meters), or kg/m . The
acceptable range of the BMI has been given in the United
States as 19-25 (Bray, 1979~. The upper limit has been
well defined by many studies on the risks associated with
overweight. The lower limit of 19, below which risks are
said to increase again, is probably an artifact of life
in industrialized countries (Rhoads and Kagan, 1983~.
People tend to have low weight if they are heavy smokers,
alcoholics, or in some way ill. In contrast, the average
BMI of healthy people in Third World countries is typi-
cally about 19 (Eveleth and Tanner, 1977), so half the
population is lighter than this. Shetty (1984) in
Bangalore has described poor Indian laborers who are
active and apparently fit with a BMI of 16. It is
interesting that, in the famous semistarvation experiment
of Keys et al. (1950), the BMI of the American volunteers
had fallen after 24 weeks to about 16, like that of the
Indians. However, unlike the Indians, the Americans were
physically and psychologically in a poor state. Young
women with anorexia nervosa often have a BMI of about
14, while free of symptoms and indeed hyperactive. I am
not saying that it is acceptable to have such a low BMI;
what I am saying is that to my knowledge no one has
systematically explored the functional effects of low
body weight in adults or attempted to define a rational
lower cutoff point for BMI.
Children have a different and even more difficult
problem. In the community, nutritional state usually has
been assessed by deficit in weight for age, compared
with a standard based on children in the United States.
Leaving aside the question of whether the standard is
appropriate, the index weight for age is unsatisfactory,
because it lumps together children of low weight for
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48
height with those of low height for age. Physio-
logically, these are different conditions, which, of
course, can appear together. Children who are short for
their age are sometimes called chronically malnourished,
but I have called them "stunted"; the word might not be a
good one, but it describes what we actually see. The -
distinction between low weight for height and low height
for age is of great public health importance. If we
remove from the "malnourished" category children who are
simply stunted, with normal weight for height, the
prevalence of malnutrition in preschool children will, in
general, be reduced by a factor of at least 5 (Table 1~.
This is not just an attempt to fiddle with the numbers by
changing the rules of the game. It is obviously
essential to reach a decision on the question: ''Are
stunted children malnourished in any useful sense of the
word?"
I think it is incontrovertible, from the work of
Martorell (1985) and others, that stunting in the Third
World is determined mainly by environmental, and not by
genetic, factors. Two opposing views about its signi-
ficance have been put forth. The first, exemplified by
the economist Seckler (1982), is that stunting is a
useful adaptation: a small child needs less food and is
therefore less likely to die when food is short. Anyway,
TABLE 1 Prevalence of Malnutrition in Children Less
Than 5 Years Old According to Diagnostic Criterion
Condition
Malnourished,
according to
weight for age
Proportion of Children, %
Vietnam
Refugees
66
Napalese Sri Lankans
56
32
Malnourished, 11 7 7
excluding those
who are only
stunteda
aReduced height compared with international standards,
but normal weight for height.
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49
what is the point of having long legs? As Mark Twain
said, nature is wonderful--our legs are always long
enough to reach to the ground. The other view is that
every child has a right, according to the United Nations
Declaration of Human Rights, to develop his full genetic
potential. Both these views are based on values. It is
better for a child to survive than to die, but this is
not a sufficient criterion. Performance must be -
considered, and here there is some disagreement in the
evidence. If the hillman in Nepal can carry TOO kg,
twice his body weight, from the plains of India to the
frontiers of Tibet, which none of us here could do, can
we say that he is handicapped by being small? Several
studies have shown that, in terms of maximal working
capacity per unit of body weight, these stunted children
are as fit as or fitter than their taller and heavier
counterparts, although in absolute terms they might still
be handicapped. A study in India showed that adolescent
boys who had been stunted from childhood and were short
for their age had less chance of earning wages as farm
laborers and were therefore perhaps condemned to a
vicious circle of poverty (Satyanarayana et al., 1979~.
It is well established that environmentally produced
stunting is associated with some impairment of mental
function and behavior. However, stunted children grow up
in a generally deprived environment; before any conclu-
sion can be drawn, one has to control for macroenviron-
mental and microenvironmental factors. For example, in a
recent study in Jamaica, differences in height accounted
~ _ ~ __ ~ To _ ~ ~ =~ .~_ a; ^~ ;~ TO
lUL ALIT} 1V~ w' ~ vow ^, _~. The mortality
associated with a given degree of stunting in Zaire is
different from that in Bangladesh (Van Lerberghe, 1983~.
Several similar studies have been conducted, but many
more are needed to get a clear idea of what it means to
be stunted. It is not going to be easy to get a general
answer to the question of whether stunting matters.
One can take the position that any handicap matters,
but not much can be done about it until one knows the
cause or, more precisely, the relative importance of
different causal factors. I believe that stunting is
nutritionally determined, that it results from a relative
deficiency of protein or factors associated with protein
(see Golden, 1985), and that it can be prevented with
specific nutritional measures. Whether such prevention
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so
should have a claim on scarce resources will depend on
what we find out about the extent of the handicaps.
ADAPTATION
The Indian laborers that I mentioned earlier were
very thin, with only 6% body fat, but apparently fit.
They also had very low food intakes. Many groups of
people seem to subsist quite well on energy intakes much
even w ten
allowance is made for their low body weight. I believe
that the new FAO/WHO/UNU (1985) requirement estimates are
based on sound physiological evidence. However, most of
it came from work in developed countries. What are the
possibilities of some mechanism of long-term adaptation
to low intakes? At least half our energy intake is
lower than their estimated requirements,
needed for the essential processes of maintaining life
represented by the basal metabolic rate (BMR). In the
Indian subjects whom I have cited as an example (Shetty,
1984), the BMR was 17% below the expected rate; that
In theory, several
factors could contribute to ants saving: lower rates of
protein turnover and ion transport; more efficient
formation of ATE, the basic unit of energy transduction
in the body; and more efficient use of ATP. All these
are hypothetical, but possible (Waterlow, 1986~. A
useful economy can possibly be achieved by a summation of
many small changes. Because they are small, they will be
difficult to detect and measure, but we should at least
try.
,,
constitutes a considerable saving.
The next need for energy is for physical activity.
~ ~ ~ not for all, energy cost is
For most activities, although
proportional to body weight, so here again cne sma''
person has an advantage. If one has a given task to
perform, such as walking 5 miles or plowing a field, and
time is no object, there could be a most economical rate
of doing it--neither too fast
nor too slow. The findings
of physiologists vary on this, and the optimal rate
depends on the load. I think it quite likely that for
many purposes it is more efficient to work slow than fast
and that people have developed by experience the most
economical pattern of work. We badly need accurate
studies on this subject under the conditions of
developing countries.
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51
Skeletal muscle contains two types of fibers, the
so-called fast-twitch and slow-twitch fibers, with
different functions. There is some evidence that the
slow fibers are biochemically more efficient than the
fast fibers and use less energy for the production and
maintenance of a given force. The relative proportions
of these two types of fibers in a particular muscle are
not necessarily the same in every person. Therefore, one
would expect that people with a higher proportion of slow
fibers would be able to work more economically. Exercise
physiologists believe that the capacity to be either a
sprinter or a marathon runner is determined by genes, not
by training. Perhaps Third World people have undergone a
genetic selection of fiber types that allows work to be
done in the most economical way.
I have discussed these speculations in more detail
elsewhere (Waterlow, 1986), but they open lines of
research relevant to the problems being considered here.
INFECTION
So much has been written on nutrition and infection
that I hesitate to add to it. I wish to refer here not
to specific infections, such as measles and malaria, that
are preventable by specific measures, but to the much
less well-characterized diarrhea! diseases and
respiratory infections. The point is often ignored that
the biggest risk factor for dying from an infection is to
be very young. Figure 1 is based on data from the Pan
American Health Organization (PAHO) Child Mortality
Survey (Puffer and Serrano, 1973~. Even if the neonatal
period is excluded, twice as many deaths occur between
the ages of 1 and 6 months as between the ages of 6 and
12 months. Almost half the deaths were attributed
retrospectively to diarrhea! disease, even though most of
the children were breast-fed. The prevalence of diarrhea
is certainly higher in the second 6 months, but the
mortality is higher in the first 6 months.
Why should these infants be so susceptible? Evidence
is accumulating that growth in both weight and length in
these poor communities begins to falter in many cases
well before 6 months of age, presumably because the
mothers, themselves undernourished, cannot produce enough
_ ~
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52
~ 24
o
-
I
111 1 6
C)
o
m
z
a:
8
o
_ ~
6 7 8 9
% OF DEATHS FROM DIARRH EAS
44
C46,
51
1 2 3 4 5
AGE IN MONTHS
10 11
FIGURE 1 Proportion of postneonatal deaths in first year
of life attributed to diarrhea! disease. Data from
Puffer and Serrano, 1973.
milk. There is also evidence, from somewhat older
children, that nutritional status has little effect on
the incidence of infections, but much influence on the
duration and severity of infections (Tomkins, in press).
From observations of these kinds, I draw two
conclusions--one specific, the other more general. The
specific conclusion is that a baby well nourished during
the first 6 months of life will have a very good chance
of withstanding the infections that are almost inevitable
during the weaning period. I am glad that WHO is now
giving more attention to the question of early supple-
mentary feeding, whenever it might be needed to maintain
the health and growth of the child.
My general conclusion is that the programs that
during the last 2 decades have focused on the preschool
child (up to the age of 5 years) have to a large extent
been misdirected and wasteful, in that they have not
taken enough account of the biology of young children and
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53
of the natural history of disease in this age group. The
pattern of mortality in the first year that emerged from
the PAHO survey was for me a true eye-opener. It ran
counter to what I had been taught, which was that
children in developing countries are likely to be healthy
for the first 6 months of life, provided that they are
breast-fed. In our emergent priorities, much more
attention should be riven to the first year, because that
_ _ . ~ ~ ~ ~ · ~ ~ · ~ ~ ~
Is when the tuture or one prescnoo' can a ~ s aecerm ~ luau .
As a practical recommendation, I suggest that, wherever
there is a system for recording deaths, they be
"ratified and reported in monthly age groups for the
first year.
___ , This simple measure would provide a rapid
and sensitive index of the effectiveness of preventive
efforts.
SCARY
I have taken the opportunity of this important
meeting to suggest some ideas that are speculative or
controversial. I would like to end by making clear what
I Am not saying.
I am not saying that there is no role for
macromeasures of the kind discussed by other participants
here. To do so would be presumptuous and ridiculous.
But such measures take a long time, so we need an emer-
gency strategy.
0 I am not saying that the kind of operational
research being done under the auspices of the
Subcommittee on Nutrition of the United Nations
Administrative Committee on Coordination with the
leadership of Dr. Horwitz is not necessary and valuable.
I am not saying that action must wait for
research. As a doctor, I do my best to treat a patient
even if I do not fully understand his disease.
I am saying that rational choices about priorities
for action require more biological knowledge than we
have. My job has been to answer the question: What kind
of knowledge? I have given some examples, but the list
is far from complete. There are plenty of challenges for
the young scientist who wants to make a contribution in
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54
nutrition. Let me end by stressing again the vital
importance of basic research in nutritional science as a
foundation for effective policies. The point was made
very eloquently by Hirschman (1963~:
The lag of understanding behind motivation is likely
to make for a high incidence of mistakes and failures
in problem-solving activities and hence for a far
more frustrating path to development than the one in
which understanding paces ahead of motivation.
It should not be necessary to say this again more than 20
years later, but unfortunately it is.
REFERENCES
Bray, G. A., Ed. 1979. Obesity in America. 2nd Fogarty
International Center Conference on Obesity. National
Institutes of Health Publication No. 79-359.
Bethesda, Md.: U.S. Department of Health, Education,
and Welfare.
Elton, G. A. H. 1978.
standards of need.
Needs and Wants.
Publishers.
European diets in relation to
In J. Yudkin, Ed. Diet of Man:
London: Applied Science
Eveleth, P. B., and Tanner, J. M., Eds. 1977. Worldwide
Variation in Human Growth. Cambridge, U.K.:
Cambridge University Press.
Galbraith, J. K. 1982. A Life in Our Times. New York:
Ballantine Books.
Golden, M. H. N. 1985. The consequences of protein
deficiency in man and its relationship to the
features of kwashiorkor. In K. L. Blaxter and J. C.
Waterlow, Eds. Nutritional Adaptation in Man.
London: John Libbey.
FAO/WHO/UNU (Food and Agricultural Organization/World
Health Organization/United Nations University.
1985. Energy and Protein Requirements. Report of a
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55
Joint FAO/WHO/UNU meeting. World Health Organization
Technical Reports Series No. 724. Geneva: World
Health Organization.
Hirschman, A. O. 1963. Journeys Toward Progress:
Studies of Economic Policy Making in Latin America.
Westport, Conn.: Greenwood Press.
Jolly, A. R. In press. Contributions of the UN agencies
to nutrition: UNICEF. In Proceedings of the XIII
International Congress of Nutrition. London: John
Libbey.
Joseph, S. C. 1985. Realistic approaches to world
hunger: public health measures. Food Nutr. Bull.
7~1~:5-9.
Keys, A. B., J. Brozek, A. Henschel, O. Mickelsen, and
H. L. Taylor. 1950. The Biology of Human
Starvation. Minneapolis: University of Minnesota
Press.
Lipton, M. 1983. Poverty, Undernutrition, and Hunger.
World Bank Staff Working Papers No. 597. Washington,
D.C.: World Bank.
Martorell, R. 1985. Child growth retardation: a
discussion of its causes and its relationship to
health. In K. Blaxter and J. C.
Nutritional Adaptation in Man.
Puffer, R. R., and C. V. Serrano.
Waterlow, Eds.
London: John Libbey.
1973 Patterns of
, , .
Mortality in Childhood. Report of the Inter-American
Investigation of Mortality in Childhood. Pan
American Health Organization Scientific Publication
No. 262. Washington, D.C.: Pan American Health
Organization.
Rhoads, G. G., and A. Kagan. 1983. The relation of
coronary disease, stroke, and mortality to weight in
youth and in middle age. Lancet 1:492-495.
Satyanarayana, K., A. N. Naidu, and B. S. Narasinga Rao.
1979. Nutritional deprivation in childhood and the
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56
body~size, activity, and physical work capacity of
young boys. Am. J. Clin. Nutr. 32:1769-1775.
Scrimshaw, N. S. 1985. Realistic approaches to world
hunger: policy considerations. Food Nutr. Bull.
7~1~:10-14.
Seckler, D. 1982.
tlSmall but healthy: a basic
hypothesis in the theory, measurement and policy of
malnutrition. In P. V. Sukhatme, Ed. Newer Concepts
in Nutrition and Their Implications for Policy.
Pune, India: Maharashtra Association for the
Cultivation of Science, Research Institute.
Shetty, P. S. 1984. Adaptive changes in basal metabolic
rate and lean body mass in chronic undernutrition.
Human Nutrition: Clinical Nutrition 38C:443-451.
Streeten, P., S. J. Burki, M. ul Haq, N. Hicks, and
F. Stewart. 1981. First Things First: Meeting
Basic Human Needs in the Developing Countries.
Oxford: Oxford University Press for the World Bank.
Tomkins, A. M. In press. Protein energy malnutrition
and risk of infection. Proc. Nutr. Soc.
United Nations University. 1984. Strengthening
developing country institutions concerned with food
and nutrition. Food Nutr. Bull. 6~3~:17-28.
Van Lerberghe, W. 1983. Anthropometric assessment of
young children's nutritional status as an indicator
of subsequent risk of dying. J. Trop. Pediatr.
29:69-75.
Waterlow, J. C. 1981. Sixth Boyd Orr Memorial Lecture.
Crisis for nutrition. Proc. Nutr. Soc. 40~2~:195
207.
Waterlow, J. C. 1986.
Metabolic adaptation to low
intakes of energy and protein. In R. E. Olson, E.
Beutler, and H. P. Broquist, Eds. Annual Review of
Nutrition, Vol. 6:495-521. Palo Alto, Calif.:
Annual Review Inc.
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57
DISCUSSION OF PROFESSOR WATERLO~'S PAPER
DR. MARTORELL: Dr. Waterlow has said a number of very
important things, particularly on the subject of small
body size and on whether stunting merits concern. I
would like to present for consideration a scenario in
which we have moved into the twenty-first century, and
economic development has already taken place. There -are
no problems of malnutrition, and a group of nutritionists
is told by a government, "We don't have any small people
anymore and we need them for intergalactic travel. Fuel
and food requirements will be reduced if flights are
staffed with small people. So, the question is, what is
the formula for small people? How can we produce small
people?" The answer would be that one would need to
interfere with development in early childhood--and would
require frequent infections, particularly diarrhea!
diseases; very poor diets, with nutrient deficiencies and
limitations in energy; and problems with infant feeding,
such as inappropriate timing of complementation of breast
milk. The formula would specify these and other factors,
and we would have to admit that production of small
people would be very inefficient, because many children
would die. There would be effects other than small size
on a variety of functions, including mental development.
There would be reduced immunocompetence and more severe
infections. Wasting would also result; small people
could not be produced without wasting, because the two
conditions are very closely related.
.. ~. . ~
In summary, the
formula for small people would be infection, poor diets,
and malnutrition during early childhood.
If we focus on the causes of small body size, rather
than on small body size itself, we obtain a different
perspective on whether stunting merits concern. Focusing
on small body size alone is misleading.
Males who sur-
vive the tumultuous early period and Become small adults
are able to function in most settings, but agricultural
productivity may be impaired. For small adult females,
there are likely to be problems in reproduction, and the
next generation would be affected. Although the energy
requirements for agricultural tasks might be reduced and
less food might be needed to survive and work, small body
size should not be seen as an adaptation. It is the
formula for producing small people that I want to
emphasize as the problem.
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58
DR . WATERLOW : I agree that we need to know the
causes. I take the simplistic view that the deficit in
linear growth is an effect of inadequate protein intake;
it is related to a specific factor or some substance
associated with protein. I do not agree that
biologically the phenomena of wasting and stunting are
necessarily connected. In real life, of course, cney are
often connected, but there is no statistically valid
association throughout the world between stunting and
wasting, as Dr. Mahler has shown. Still, I agree that we
need a better analysis of the causes.
DR. SCHORR: My question has to do with nutritional
assessment. In the light of Dr. Mellor's comments on the
numbers of malnourished people in the world today, are
the current nutrition assessment tools and derived
indicators sensitive, specific, and adequate to detect
the extent of malnutrition, and are the types of data
being reported or the methods of reporting accurate?
What type of research or practical applications would
improve the quality of data for assessing the severity of
global malnutrition?
At the nutrition congress, Dr. Rohde addressed some
of these issues.
Perhaps he could speak on this issue.
Is there a problem with this reporting? Is it a problem
with severe malnutrition or mild-to-moderate malnutri-
tion? What sorts of things can be done? There appears
to be some sort of a gap between assessment and accurate
reporting.
DR. WATERLOW: Of course there is a problem. The
whole thing is a continuum from perfectly healthy to
dead, and you can assess where you are on it through
various anthropometric methods. What we all want to know
are the functional consequences of being at any point on
the continuum--not an easy thing to determine. It will
be necessary to decide what functions you are interested
in--physical work, mental development, or behavior. The
relation between an anthropometric deficit and a func-
tional deficit depends strongly on culture and on all
sorts of factors. ~ ~ ~ ~ ~~
The risk of excess moray an a
given weight deficit is about 5 in Bangladesh and 1.5 in
Zaire. Presumably, there is a range of different factors
in these two countries. The same would apply to any
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so
functional deficit, and this idea that you can take some
measurements and assess them in some sort of accurate way
is simply a cloud. What we can do is identify children
who are in a serious nutritional state. There might be
some argument at the edges, but anyone who has worked in
clinical nutrition can do this.
Those are the people
whom I am suggesting we concentrate on. Otherwise, we
are doing nothing.
UNIDENTIFIED SPEAKER: In the slide you showed [Figure
1], the case-fatality declines over the preschool years,
with the peak in the age group of 1 month. How much of
that was not confounded by the low birth weight of these
babies? This makes us wonder how early is early enough
for intervention, such as changes in maternal nutrition
during pregnancy.
DR. WATERLOW: That is a very good question. It was
not the case-fatality ratio that declined, it was the
actual number of deaths. I left out the neonatal
period. Results of the work in Guatemala and Costa Rica
suggested that a very high proportion of the neonatal
deaths result from prematurity. There are, of course,
other complications. I agree that we should intervene as
early as possible in pregnant women. Dr. Whitehead's
results in West Africa suggested that supplementary
feeding of pregnant women can have a significant effect
on birth weight. So, I agree, we should start as early
as possible.
DR. ROHDE: There is considerable basis for debate
over the question of functional significance of
smallness, and one can look at it either from the
perspective of Dr. Martorell (how to get a small
population) or from the perspective that Dr. Waterlow has
offered (how to deal with this huge problem in the world
and focus our resources on the people who need them the
most). The latter gives us the perspective that
Dr. Waterlow offered of looking at the most severely
malnourished and deciding what can be done about them,
what the functional consequences are. and which of them
are most in need of help
I suggest a compromise.
think that the implication in the comments is that, if we
start early enough and take the appropriate measures, we
will not have to tolerate either wasting or stunting.
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60
We should start interventions very early, as was just
pointed out, during the prenatal period, or (as
Dr. Martorell suggested) even one generation ahead. We
should look for healthier mothers and healthier children,
monitor the growth of the children, and do something
about it in the first 6 months of life. Thus, we do not
wait until we have a malnourished child on our hands who
all of us find to constitute an almost impossible
clinical task. That is how we have to approach it.
Although the preventive approach does commit us to do
something for every child, a later approach to those who
are malnourished does not seem to be within our capacity.
DR. WATERLOW: I like to agree with compromises. I
agree with you, Dr. Rohde, about a concentration on the
first 6 months of life. I also think that for countries
where there are many seriously malnourished children, we
have to do something about it. We have to show a
willingness and an ability to save those children's
lives. This will also make a contribution to mothers'
understanding of how to treat their children.
UNIDENTIFIED SPEAKER: If we omit the very severely
malnourished child, how comfortable are you that we know
chat ~nthrnn~m~tri ~ tori sari ~ should be applied during the
r r ~ ~
first 6-12 months of life to identify the small child
that you and Drs. Martorell and Rohde have referred to?
DR. WATERLOW: That is impossible to answer. How
appropriate are criteria? All we can do is work
according to results. -~
What an ordinary person ages, 1
think, In looking alter children is say that, if they are
at a particular weight at a particular age, they are
pretty healthy and,
that, they are not.
if they are beginning to fall below
This attempt to define quantitative
cutoffs granted that we have to have growth charts and
references, is not terribly useful.
UNIDENTIFIED SPEAKER: I would like to return to
nutritional science. As you said, we are in a state of
transition in nutritional science. Much of nutritional
research is retreating or being partitioned among the
basic sciences these days, and room for nutrition itself
in the laboratory is disappearing.
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61
At the some time, advances in genetics might entirely
change the way we view requirements within the next
10-20 years. I suspect that the role of nutritionists
will change, and even the name. I am concerned that the
baby not be thrown out with the bathwater in all
this--that the multidisciplinary focus on human beings be
maintained in this process.
With regard to your recommendation that more
institutes of higher education and nutrition be set up in
developing countries, I am worried about the degree to
which people are willing to invest in such institutions.
If they are unwilling to send students to industrialized
countries to study science and to pay for a full course
of study--not just 3 or 6 months, but the full 5 years
that it takes to bring people to the expertise expected
of scientists here--we are going to be fostering a form
of international apartheid where we have different
standards. We have a misleading separate-but-equal
concept of what institutions will do overseas. Do you see
that as a concern as to the amount that should be
invested in these institutions?
DR. WATERLOW: Thank you for your comment about
nutritional science in general. As far as the insti-
tutions are concerned, I was not suggesting that vast
numbers of completely new institutions be established.
My own work has always been in a special institute within
a university and medical school. Universities and
medical schools need to be strengthened. My attitude
has been that people from developed countries have the
responsibility to help to develop the intellectual
potential of people in the developing countries. I do
not accept that there are necessarily going to be
first- and second-class citizens. In Jamaica, we have a
master of science course in nutrition that is recognized
as being good as any. There is no reason for the
situation to be otherwise--and it is not--for courses in
India and other parts of the world. I think that it is a
colonialist point of view to say that it is bound to be
worse because it is there, rather than here.
. . . . . .. . .
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Representative terms from entire chapter:
body size
