nutritional status among lactating women. These are all discussed below along with a summary of the normative data that are available on the nutritional status of well-nourished lactating women.
In general, assessments of the nutritional status of lactating women and other groups have many applications—in research, in patient management, in public policy development, and in program planning and evaluation. The selection of the indicator of nutritional status to be used should consider its intended application (Habicht and Pelletier, 1990).
To date, there have been few efforts to develop indicators specifically for the assessment of nutritional status among lactating women (Rasmussen and Habicht, 1989). Most indicators are normative; that is, they reveal how an individual's value for that indicator compares to some standard, usually derived from a population of normal, healthy subjects. Values outside a range defined by designated cutoff points are called abnormal, but may or may not be associated with any particular functional consequence. An example of a normative indicator is the comparison of weight for height or blood nutrient values to a reference standard. As discussed further below, no standards for anthropometric or biochemical indicators have been established for nutritional status among lactating women. The usefulness of values obtained from nonpregnant, nonlactating women as a reference standard for lactating women requires evaluation.
There are few indicators of risk of undesirable outcomes for lactating women. Instead, the risk is usually related to the health of the nursing infant. An example of such an indicator is an abnormally low concentration of riboflavin in milk, which is associated with the likelihood of nutritional deficiency in the nursing infant (Bates et al., 1982). Another is the classic association of low thiamin concentrations in the milk of mothers in a rice-eating population with a high incidence of infantile beriberi among breastfed babies (Kinney and Follis, 1958). In contrast, indicators of poor nutritional status with respect to certain micronutrients (e.g., iron) are well understood in lactating women and can be used for the targeting of nutrient-specific interventions.
Indicators of benefit (ways to identify lactating women who would benefit from a planned intervention) have yet to be developed. These would be the most useful indicators for targeting interventions. The theoretical work needed to develop indicators of benefit from interventions designed to ameliorate protein energy malnutrition has been started in studies of young children (Rothe, 1988). It is clear from a supplementation trial conducted in The Gambia (Prentice et al., 1983; see Chapter 5) that the indicators of poor nutritional status used (residence in a low-income community characterized by seasonal decreases in milk volume or low weight for height) are inadequate for predicting who will