Body composition in chronic undernutrition.

Anthropometric (height, weight, and skinfolds), biochemical (serum proteins, albumin, and cholesterol), metabolic (nitrogen balance and creatinine excretion), hematological (plasma volume, hemoglobin, hematocrit, bone marrow hemosiderin, percent transferrin saturation, vitamin B12, and folic acid) variables and body water compartments (total and extracellular) have been measured in 49 adult male subjects who exhibited a wide range of nutritional states from normal to severely undernourished. Changes in body composition associated with moderate degrees of nutritional compromise were related principally to decreases in body cell mass (-15%). Body fat was normal. With severe nutritional involvement, both fat depots (-29%) and body cell mass (-29%) were significantly diminished. Muscle cell mass was more affected than other cells in the body (-41%). These data could indicate that in the group with moderate compromise, energy reserves (and hence energy balance) were maintained but dietary protein deficiencies were not compensated for. Both calorie and protein deficiencies were evident in the subjects with severe undernutrition. Multiple regression equations (r greater than 0.8) were developed that allow prediction of muscle cell mass, fat-free weight, and body cell mass from simple anthropometry and serum albumin levels. Decreases in serum albumin concentration were best related to deficits in muscle mass (r = 0.77).