do not provide quantitative guidance.17 These recommendations were promulgated for all healthy adults, including the elderly.
Anthropometric indices of nutritional status such as weight, stature, and skinfolds, as well as changes in these indicators, correlate well with clinical and laboratory markers, at least in young and middle-aged adults. They pose difficult problems for use in the elderly, however, because there are no norms for body composition in older individuals. Some of the usual anthropometric measures (e.g., stature) may be difficult to obtain, especially in the very old; as a result, substitutes such as segmental measurements of the head to the knee may be more useful. Also, special equipment and extensive training in its use may be required for some of the more elaborate measurements. Yet despite these limitations, even simple, standardized measurements of weight can be helpful in monitoring nutritional status and are easy enough to be performed by anyone, given minimal training.
Because most anthropometric measurements of body composition are rather nonspecific, they are best utilized in combination with other measurements. Indeed, the combination of clinical observations with biochemical, anthropometric, and dietary indices is thought by nutritional scientists to best reflect the specific physiological ''functions" of interest for nutritional research purposes. For example, functional tests of light adaptation coupled with clinical and dietary data may be used as measures of vitamin A nutrition. Whether a diet is adequate to rehabilitate a starved individual can be assessed by its ability to generate weight gain. For clinical purposes, however, these standard assessment methods are less useful than feeding evaluations to determine by observation whether individuals are able to and actually do eat unassisted. Finally, it is necessary to assess the effects on functioning that may arise from nutritional or other treatments (for example, home internal feeding by pump, which is a complex, time-consuming procedure).
Another approach to assessing "functional" nutritional status is to develop a battery of biochemical and clinical tests that serve as predictors of morbidity and mortality and assist clinicians in determining the appropriate course of further treatment for the patient.