Comparison of methods of estimating body fat in normal subjects and cancer patients

Abstract

Total body fat can be indirectly estimated by the following noninvasive techniques: determination of lean body mass by measurement of body potassium or body water, and determination of density by underwater weighing or by skinfold measurements. The measurement of total body nitrogen by neutron activation provides another technique for estimating lean body mass and hence body fat. The nitrogen measurement can also be combined with the measurement of total body potassium in a two compartment model of the lean body mass from which another estimate of body fat can be derived. All of the above techniques are subject to various errors and are based on a number of assumptions, some of which are incompletely validated. These techniques were applied to a population of normal subjects and to a group of cancer patients. The advantages and disadvantages of each method are discussed in terms of their ability to estimate total body fat.

Body composition and time course changes in regional distribution of fat and lean tissue in unselected cancer patients on palliative care—Correlations with food intake, metabolism, exercise capacity, and hormones

“…19 Numerous investigations on alterations of body composition in undernourished individuals and patients have been published based on a variety of methods, including plain antropometric measurements, 20 -22 whole body potassium determinations, 1,[23][24][25] neutron activation analysis, 26,27 computerized tomography, 28 bioelectric impedance measurements, 29,30 and DEXA measurements. 20,[31][32][33][34] All of these techniques have various advantages and limitations. During recent years, the DEXA technique has become a gold standard due to its reproducibility and simplicity, particularly in repeated follow-up measurements.…”

“…21,27,32 These discrepancies may depend on the fact that various techniques with different limitations were used or that various groups of patients have different time course changes. 33 However, most studies indicate that body fat declines when patients suffer from progressive disease, whereas alterations in fat-free mass or lean body mass may be either inconclusive or decreased. 21,37 A well established opinion in medical handbooks and consensus discussions is that lean tissues, particularly skeletal muscles, are lost rapidly, a fact that may represent an important issue from the patient's perspective.…”

Análise crítica do uso do índice de massa corporal para idosos

“…Problema associado a qualquer metodologia de determinação dos pontos de corte é o fato de não se saber claramente como levar em consideração a idade, já que com o envelhecimento ocorrem simultaneamente aumento na deposição de gordura e uma perda da massa livre de gordura 37 .…”

Estimation of body fat from skinfold thicknesses in middle‐aged and older men and women: A multiple component approach

“…Protein, an important constituent of FFB composition, was not assessed, and its inclusion in the criterion estimate of body composition together with THW and BMD may have further reduced the age-related error in the relationship between skinfolds and D,. Although accounting for individual variation in protein content is theoretically appropriate, there is presently no consensus on how the protein content of the FFB varies with age (Cohn et al, 1981;Heymsfield et al, 1989;Shephard et al, 1985). The use of regional as opposed to whole body dualphoton absorptiometry (DPA) in the present study precluded the estimation of protein content from measurements of TBW, total body bone ash, and D, as recently outlined by Heymsfield et al (1990).…”