Body composition of humans: comparison of two improved four-compartment models that differ in expense, technical complexity, and radiation exposure
Nutritionists are recognizing flaws in the traditional two-compartment model of body composition, in which the body weight is divided into fat and lean components. New four-component models are gaining favor, but the measurements involved are significantly more costly and complex. Four-compartment models divide the body into aqueous (water-based), protein, mineral, and fat components. A definitive method of measuring nitrogen in the body (which represents proteins) and mineral composition is neutron activation analysis, which uses a plutonium neutron source and sophisticated instrumentation. Neutron activation analysis is clearly unsuitable for routine use at most medical centers. However, in a comparison of two methods of determining body composition, researchers have found that a simpler method using dual-photon absorptiometry gives results which are comparable to those achieved with neutron activation analysis; the technique is also accessible to a greater number of researchers. Both techniques estimate the amount of water in the body by observing the dilution of a known quantity of radioactive water. Quantities of minerals measured with the absorptiometry may then be compared with explicit values determined by precisely measuring the bone mass and dissolved minerals in cadavers. The results showed a typical adult body to be about 53 percent water, 15 percent protein, 5 percent mineral, and 27 percent fat. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: American Journal of Clinical Nutrition
Maternal body fat and water during pregnancy: do they raise infant birth weight?
The amount of lean tissue a pregnant woman has influences her baby's birth weight more than the amount of body fat. This was the conclusion of researchers who measured pre-pregnancy weight, body fat and lean tissue in 200 pregnant women. Body fat had no influence on infant birth weight, but weight and the amount of lean tissue did. Different body compositions may explain why two women of similar weight can produce similar weight babies even though one woman gained much more weight during pregnancy.
Publication Name: American Journal of Obstetrics and Gynecology
- Abstracts: Single-center comparison of results of 1000 prenatal diagnoses with chorionic villus sampling and 1000 diagnoses with amniocentesis
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- Abstracts: Epidermal growth factor receptor expression in normal ovarian epithelium and ovarian cancer. Overexpression of HER-2/neu in endometrial cancer is associated with advanced stage disease
- Abstracts: Relation of body fat patterning to lipid and lipoprotein concentrations in children and adolescents: the Bogalusa heart study
- Abstracts: Supplemental-chromium effects on glucose, insulin, glucagon, and urinary chromium losses in subjects consuming controlled low-chromium diets