404 PAHO BULLETIN l vol. 18, no. 4, 1984
GLOBAL TRENDS IN PROTEIN-ENERGY MALNUTRITION
Measuring Protein-Energy Malnutrition One of the basic problems in dealing with protein-energy malnutrition is determining how to measure it. Traditionally, weight-for-age has been the most common indicator used in estimat- ing the prevalence of such malnutrition, though occasionally clinical assessments and biochem- ical analyses have also been used. The first es- timate of global malnutrition’s prevalence was based on surveys using a combination of these indicators together with a few studies using weight-for-height as the malnutrition indicator. Although it is now known that weight-for-age is a composite indicator of two other more spe- cific indicators-weight-for-height (wasting) and height-for-age (stunting)-these two mal- nutrition indicators were seldom used in surveys done before the mid- 1970s.
A recent collection of global malnutrition data that included weight-for-height, height-for-age, and weight-for-age indicators showed that the percentage of children with low weight-for-age was in general closer in value to the percentage of children with low height-for-age than it was to the percentage with low weight-for-height. Low weight-for-age particularly reflected per- centages of children with low height-for-age in groups over two years old. Contrary to the image of malnourished children generally brought to mind as the result of media coverage of famine, stunting is the dominant form of malnutrition, not wasting or emaciation.
When studying trends in the prevalence of protein-energy malnutrition, as defined by the percentage of children with low weight-for-age, it is impossible to determine whether or not
changes are due to changes in the percentage of emaciated children, or changes in the stature of children, or a combination of these two. Even if the percentage of low height-for-age children did not change, but remained approximately the same over a given time period, it is quite possible that wasting (emaciation) may have increased and stunting decreased, or vice versa. Malnutri- tion indicators are further complicated by the fact that while wasting is due to acute, current malnutrition, stunting may be the result of either previous or chronic malnutrition. Despite these drawbacks to the use of weight-for-age as a mal- nutrition indicator, it was necessary to choose this indicator because it is the only one used consistently over the twenty-year time span ( 1963-1983) of the study reported here.
0 ABSTRACTS AND REPORTS 405
Table 1. Estimates of the prevalence of protein-energy malnutrition in developing regions. The percentages shown are the percentages of children found by various surveys (see footnotes) to be at least two standard
deviations below the U.S. National Center for Health Statistics median weight for age.
Proportion malnourished in indicated age group (in years)
o-4 Crude estunate of 0 I 2 3 4 (average) No. malnourished
The Americas (excluding temperate countries)
1963-1973a 1973-1983b
Afrrca:
1963-1973’ 1973- 1 983d
Asia (excluding the USSR and NortheastAsia; weighted forlndiaJ:
1963-1973= 1973-1983’
Oceania (excluding Australia andNewZealandJ:
1963-1973g 1973-1983h
15.0% 9.8%
32.9% 21.9%
27.8% 21.3%
25.3% 17.4%
27.6% 17.9%
25.9% 17.7%
10.8 million 8.6million
18.6% 15.1%
40.5% 35.2%
36.7% 29.9%
31.4% 23.9%
28.1% 23.8%
31.1% 25.6%
19.9 million 21.9 million
24.9% 25.9%
62.8% 60.0%
66.1% 61.4%
54.2% 60.2%
45.3% 62.5%
50.6% 54.0%
94.8 million 114.6 million
15.6% 3.9%
26.8% 21.3%
20.3% 17.3%
23.4% 5.6%
24.0% 9.0%
22.0% 11.5%
0.5 million 0.3 million
‘8,440 children were studied in Surveys of Belize, Bohvia, Brazd, Colombia. Costa Rica, Dominica, the Dominican Republic, Haiti,
Honduras. Jamaica, and Nicaragua.
b20.720 chddren were studied III surveys of Barbados, Colombia, Costa Rica, El Salvador, Guatemala, Guyana, H&I, Hooded, Jama~a. Nicaragua. Panama, St. Vlcent and the Grenadines. Trinidad and Tobago, and the Turks and Caicos Islands.
‘5.576 children were studied in surveys of Burundi, Ivory Coast, Ltbyan Acab Jauhniya, Malawi, Sudan, Togo, Tunisia, Uganda, and the United Republic of Tanzania.
d45.084 chddmn were studied in surveys of Cameroon. Egypt, Ethiopia, Ghana, Guinea, Gumea-Bissao. Lxsotbo, Libena, Madagascar, Nigeria, Sierra Leone. Togo. Tunisia, Uganda. Upper Volta, and Zaire.
‘37.050 children wece studied in surveys of Democratx Yemen, India, Iran, the Philippines, and the Yemen ,&ah Republic. ‘25.673 chddmn were studied in sunreys of Bangladesh, Burma, Democratic Yemen, India, Indonesia, the Islamic Repobbc of Ino, Jordan. Malaysia, Nepal. Sri Lanka. and Yemen.
p787 chddren were studied in a survey of tbe Solomon Islands
hl ,519 chddreo were studled in surveys of Papua New Guinea, Kiribatl, and Western Samoa.
Prevailing Trends, 1963-1973, and 1973-1983
pen, and so any estimate of protein-energy mal- nutrition prevalence must be very gross. Sample size is the greatest limitation in estimating global trends; specifically, during the first 10 years the surveys measured 52,000 children in 29 coun- tries; during the second 10 years they measured 93,000 children in 43 countries. The same coun- tries were not necessarily surveyed in both time periods; in fact, the countries represented appear to be maldistributed. Also, national surveys were more likely to be done in the last 10 years than in the previous 10 years. Therefore, it is For the study reported here, worldwide trends
406 PAHO BULLETIN l vol. 18, no. 4, 1984
impossible to determine whether malnutrition is definitely getting better or worse; only an ap- proximation of trends can be seen.
When data from the Americas, excluding the temperate countries (Canada and the United States of America, Chile, Argentina, the Falk- land Islands, and Uruguay), were averaged by age group, each group showed a trend toward improvement; in other words, proportionately fewer children were found to be malnourished (as defined by low weight-for-age) between
1973 and 1983 than between 1963 and 1973. The same could be said for Africa. However, while there may have been some improvement in decreasing “absolute” numbers of mal- nourished children in the Americas, Africa’s population increases caused the numbers to re- main approximately the same in this time-span. In Oceania, the country surveyed during the period 1963-1973 is not sufficiently representa- tive to permit a general statement about prevail- ing trends. When the data for Asia (weighted for India and excluding the USSR and the North- east Asian countries of China, Hong Kong, Japan, Macao, Mongolia, and the Republic of Korea) were averaged, no percentage improve- ment appeared; and in fact the data suggest the situation may have worsened.
Overall, even though the percentage of mal- nourished children in developing areas indicated by weight-for-age data does not appear to be
increasing, the growth in population over the past 20 years appears to have caused the number of malnourished children under five years of age to be somewhat larger than it was 10 years ago.
Gross estimates of the numbers of malnour- ished children in these regions, based on weight- ed one-year age groups and the 1963-1973 and
1973-1983 surveys, yield totals of 126 and 145 million malnourished children, respectively. However, there are probably individual coun- tries in each region which were able to decrease the number of malnourished children during this same time period, while others may have experi- enced a dramatic worsening of the situation.
Furthermore, these numbers only give very gross trend estimates and do not tell how many children are wasted or stunted, and how many are currently or previously malnourished. In the future, it may be possible to make a better esti- mate of trends and to shed more light on specific types of malnutrition by using the more specific indicators of weight-for-height and height-for- age; in the meantime, however, the information presented here at least gives a retrospective view of this global problem and may be of use in trying to find solutions.
Source. World Health Organ~zatmn, Weekly Epm’emrolog~ca/Rec- ord 59.189-192, 1984 A hst of references for this rep-! IS awlable upon request from the Umt of Nutrmon. Dw~sion of Famly Health, World Health Organm~m, 121 I Geneva 27, Swmerland.
HUMAN GENETICS AND PREVENTION OF CORONARY HEART DISEASE
Since the beginning of this century, dramatic progress has been made in the treatment and pre- vention of diseases that are largely determined by environmental factors or by specific genetic defects. One consequence of this progress is that many of the most important residual causes of morbidity and mortality in developed societies are diseases of complex etiology-such as
cancer, heart disease, mental illness, and birth defects-in which both genetic and environmen- tal factors may play an important role.
