Assessment of protein nutritional status in children.

When considering the effects of disease on nutritional status it is useful to think of the body consisting of lean mass and fat mass. The latter relates to energy status and the former to protein nutritional status. In addition, childhood growth in length/height is to a high degree dependent upon having an adequate protein intake. If insufficient non-protein energy is fed, then protein is used to help meet energy needs. Hence achieving an optimum protein nutritional status also requires receiving sufficient energy. Assessment of protein nutritional status starts with measurement of length/height and weight in relationship to growth standards. Next comes using mid-upper arm parameters in which the measurement of muscle area or circumference is a reflection of protein nutritional status while triceps skin-fold thickness is a measurement of energy status. Serum albumin remains the number one short term parameter reflecting protein nutritional status followed by serum transferrin. Plasma amino acid profiles can be measured but are mostly dependent on recent dietary intake and so are hard to interpret. Classically, nitrogen balance has been used as a reflection of dietary protein intake. While it has been used extensively on a research basis its clinical applicability is limited. (c) 2007 Wiley-Liss, Inc.