Systems analysis in nutrition and health planning: approximate model relating birth weight and age to risk of deficient growth.

This paper summarizes the initial phase of an effort to develop semiquantitative methods for nutrition and health planning. The general approach is to utilize the methods of systems analysis and operations research where appropriate, but the emphasis is on developing a simplified, approximate analysis that government planning groups could conveniently apply in evaluating various potential programs for attaining specific nutrition and health objectives, while satisfying certain constraints (e.g., budget, facilities, personnel). An essential element of the analysis is a model that provides an approximate description of malnutrition (inadequate growth, as indicated by weight for age) and mortality in terms of those variables that can be affected by intervention programs. We have concentrated initially on using the results of two INCAP longitudinal studies to develop models relating the incidence of malnutrition (second and third degree on the Gomez scale) to age and previous growth, including birth weight. The two studies cover rural Guatemalan communities with considerable variability in ethnic, socioeconomic, and ecological conditions. Because they are tentative, the resulting models are discussed only qualitatively and not quantitatively. The models may serve as baselines to estimate the consequences of potential programs aimed at different target groups, such as pregnant women and children whose weights at birth or thereafter fall below prescribed levels. The possible benefits of using models of this nature in nutrition and health planning are discussed.

Effects of maternal nutrition on fetal growth and infant development.

The results of a food supplementation study conducted in four chronically malnourished rural villages in Guatemala were analyzed to determine possible effects on the study children's early mental and physical development. One of two food supplements, atole and fresco, were given to pregnant and lactating mothers and the infants born to them up to three years of age. The level of supplement received was noted and the subsequent course of the children's development observed. Food supplementation of pregnant mothers was found to correlate with higher weights of their babies at birth. No other major maternal variables--home diet, body height and/or weight, morbidity, obstetric characteristics, or socioeconomic status--could account for this association. At 36 months of age the children who had received a large amount of food supplementation showed a far lower prevalence of growth retardation than did those who received smaller quantities. Again, this correlation could not be attributed to any other major maternal variables. In regard to mental development, food supplementation was found to correlate with better performance in psychological tests beginning at six months of age. At 36 months the correlations were significant in five different tests. The results of this analysis have wide-ranging implications for public health. Given the recognized association between low birthweight and infant mortality, they point especially to the importance of maternal nutrition during pregnancy in programs aimed at reducing this serious problem.