Improved models for determination of body fat by in vivo neutron activation
In the present study, two different models of body composition, based on data obtained by nuclear techniques are used. Total body nitrogen, calcium, and chlorine were obtained by total body neutron activation. Total body chlorine was used to estimate extracellular water, and total body calcium to determine bone mineral and extracellular solids. Total body potassium was measured by whole body counting to obtain the body cell mass. In addition, total body water was measured by the tritium dilution technique. It was found that either model can be used equally well to measure total body fat in normal subjects. Estimation of body fat as the difference between body weight and the sum of total body nitrogen (protein), total body water, and bone ash (model 1) appears to have an advantage over model 2, which uses body cell mass, extracellular water, and extracellular solids, particularly for patients with metabolic disorders. This advantage is partly due to the fact that the parameter protein (total body nitrogen) is less affected in metabolic disorders than the more labile total body potassium. The closely correlated results obtained with the two models based on nuclear measurements support the conclusion that these techniques provide reliable measurements of total body fat.
- Research Organization:
- Brookhaven National Lab., Upton, NY
- OSTI ID:
- 5045440
- Journal Information:
- Am. J. Clin. Nutr.; (United States), Vol. 40
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ADIPOSE TISSUE
ACTIVATION ANALYSIS
BODY COMPOSITION
BIOLOGICAL MODELS
BODY FLUIDS
CALCIUM
CHLORINE
FAST NEUTRONS
ISOTOPE DILUTION
MEN
NITROGEN
PATIENTS
POTASSIUM
TRITIUM OXIDES
WATER
WHOLE-BODY COUNTING
WOMEN
ALKALI METALS
ALKALINE EARTH METALS
ANIMAL TISSUES
ANIMALS
BARYONS
BIOLOGICAL MATERIALS
BODY
CHALCOGENIDES
CHEMICAL ANALYSIS
CONNECTIVE TISSUE
COUNTING TECHNIQUES
ELEMENTARY PARTICLES
ELEMENTS
FEMALES
FERMIONS
HADRONS
HALOGENS
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MALES
MAMMALS
MAN
MATERIALS
METALS
NEUTRONS
NONMETALS
NUCLEONS
OXIDES
OXYGEN COMPOUNDS
PRIMATES
TISSUES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES
400101* - Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures