3 for age) and wasting (weight for height) in children', although these alone do not reveal nutrition problems related to micronutrient deficiencies. Poor anthropometrv **may be** the result of non-nutritional factors as well. A good picture of protein energy malnutrition problcms of a comm-nity can obtained using these indicators nonetheless.

# Reference Values

The anthropometric reference standards are based on a population of well-nourished children. Several different reference values have been used historicaliv for these three anthropomeitric measurements. The U.S. Nsational Center for Health Statistics (NCHS) standard is ni)\% adopted bv the World Health Organization as the global reference standard. There has alwa|s hben some controversy about genetic difference between populations and if references from WesLern countries are really appropriate for children in developing countries. Some countries have, **Is a** result, developed their own rcferences. From a varietv of studies, it is clear that well-nouri-.ed children prior to pubertv have the same gro\wth potential regardless of nationalitv although thcre is variation in bodv size belt%cen social classes which is true tor both industrial and dcvcloning countries. ' A recent example of this the similarity in growth between industrial and developing countrv children is 1985 height data lor children in the Peoples' Republic of China which shows that well-nourished urban children do not differ in growth from the NCHS reference"

Data for malnutrition should bc presented as distributions--the proportion of the population falling helow a specif'ied centile. standard deviation or Z-score. or percent of the rcfercnce mcdian. Thev should not he represented as population medians or means.

In any normail distribution. 2.3l of hcalthv children fall helowv 2 standard dc,xiations of the median (-2Z). If significantlv more than 2.3'' ol' children fall below -2Z then there i a nutrition problem.

In the past most anthropomctric data \wcre expressed as proportions of' children falling bclos\ a speciieLd percent of the median. Children tIaling helow 80(1' _of_ the NiCHS median seight t'or alce or weight lor height and 90(W) of the median height for aye werc classilicd as mialnourshed. (Some researchers ma% use the C omez classifica.ion of s\eight lor age (<6(F)'' of the median {se\ere; 61-75% Of the median JmoderatcL 76-90%( ol' the median {mild); >909% of the mtedian {normal ).

The %ariancc ot' dil'l'erent indicators changes at diffcrent aces. Hence. S) perccnt of' median hc.iht '' r ace ma\ menan much morc uc\crc malnutrition at aiUc one than at **J i\_** . The Z9N ';erlos iJC.. R. Bu/ini Keller, J. Line. N.Z. Nichaman J. Tannr ( 1977). The presentation and use of hcight and weiuht data for comparing the nutritional status Of urou ps of children under thL ace Of liO \cars. Bulletin **Of** the World Health Orcani/alion >5(4) :489-4'8. "Nartorell. R. & J P. Hahicht ( l-IS(- . Crow th in vark childhood in dc\cloping counltrics. (F. Falkncr & JI.. Tanncr. ci) Humain ciro lh: a comprehcnsike Treatise. Second edition. \'olumne **3s.** Mihodoloi3: E **o1oglical.** Genetic. and Nutritional Effects on Grotlh. Neu% York and London: Plenum PrcsN Yip. R. l NS90. Girko\th ot Chiniese children: which retercnce to **assess** the erowsth **of** Chinese children.' Pro(_cedinci 11' thc 4th Initrnational S~mposium on Matcrnal and Inlant N'utrition. Chcnlu. Cthina .