Validation of expedient methods for measuring body composition in Indian adults.

The body composition of 99 men and 89 women from south India was estimated using hydrodensitometry, bioelectrical impedance and skinfold thickness. Comparisons of the hydrodensitometry (reference method) and skinfold methods showed that there were no significant differences between the methods, for estimates of fat free mass (FFM) and per cent fat. The mean difference between the estimates FFM (bias), from skinfold measurement and hydrodensitometry was small for both groups (+0.16 +/- 1.09 kg in men and +0.67 +/- 0.9 kg in women). The same trend was observed in per cent fat estimates (-0.37 +/- 2.04 in men and -1.49 +/- 2.28 in women), showing that the skinfold method can be used as an accurate and expedient method to determine body composition. The bioelectrical impedance method obtained a significantly lower FFM and higher body fat than the reference (hydrodensitometry) method. This could have been due to the use of an inappropriate equation derived from Western population studies. Hence, a new predictive equation, for the measurement of FFM by the bioelectrical impedance method was derived for this population, using the variables of height2/impedance and FFM measured by underwater weighing. The new equation for the bioelectrical impedance method then gave values of body composition which compared well (0.26 +/- 2.32 kg) in men and (0.36 +/- 2.49 kg) in women with the hydrodensitometry method.

Basal metabolism of weight-stable chronically undernourished men and women: lack of metabolic adaptation and ethnic differences.

The purpose of this study was to investigate whether weight-stable chronically energy-deficient subjects exhibit evidence of metabolic adaptation and to establish whether international predictive equations overestimate the basal metabolic rate (BMR) of tropical populations. BMR, body weight, height, and fat-free mass (FFM) by underwater weighing were measured in healthy, physically active urban dwellers of low socioeconomic status (178 men and women aged 22-38 y) in Bangalore, Southern India. Subjects were selected on the basis of body mass index (BMI; in kg/m2) and classified in three groups: severely undernourished (BMI < 17.0; n = 30 men, n = 25 women), marginally undernourished (BMI = 17.0-18.5; n = 31 men, n = 30 women), and well nourished (BMI > 18.5; n = 27 men, n = 35 women). The BMR of the well-nourished group, expressed in absolute terms (6.20 and 5.18 MJ/d for men and women, respectively), was significantly higher (P < 0.000) than that of the severely undernourished group (5.72 and 4.64 MJ/d for men and women, respectively). Normalizing BMR for either body weight or FFM by analysis of covariance abolished all differences. The mean BMR of the low-BMI study group was substantially higher (11-14%) than reported previously for undernourished Indian adults. The BMR of both men and women, regardless of their nutritional status, was accurately estimated by age- and sex-specific FAO/WHO/UNU equations. These findings suggest the absence of an enhanced metabolic response in weight-stable chronically undernourished adults. This is in contrast with earlier reports, and supports more recent views. The study also provides evidence of the absence of ethnic-specific energy turnover in Indians.

Prediction of total body water in Indian men from anthropometry and bioelectrical impedance using deuterium dilution as reference.

Total body water (TBW) obtained by deuterium dilution (TBWD) in 45 adult Indian males of low body mass index was compared with values obtained from bioelectrical impedance (TBWImp) and two anthropometry-based prediction equations. Bioelectrical impedance significantly underestimated TBW when compared with deuterium dilution, by 2.75 SD 2.86 kg. Comparisons of the anthropometry-based prediction equations demonstrated that TBW was overestimated by 0.87 SD 2.49 kg, and 2.47 SD 2.57 kg, respectively. Since all parameters in the bioelectrical impedance method were standardized, the difference in the values could have been because of the equation used. Therefore, a fresh equation for the measurement of TBW by the bioelectrical impedance method was derived using the variables of height2/impedance and weight. New prediction equations for TBW were also derived based on anthropometric variables of weight and height. Body weight has the greatest influence in the prediction equations for TBW, and the equation derived was TBW (kg) = 0.533 x body weight (kg) + 3.77, SEE = 2.4 kg. Using height2/impedance gave the relationship: TBW (kg) = 0.568 body weight-0.04 height2/impedance + 4.35, SEE = 1.9 kg.

Total body water measurements by deuterium dilution in adult Indian males and females.

Total Body Water (TBW) was measured in a group of 20 healthy adult Indian men and 10 women by the deuterated water dilution technique and their body composition was determined by applying a hydration factor of 0.7194 for fat free mass (FFM). The TBW in the male subjects whose mean body weight was 49.8 +/- 6.7 kg, was 60.6 +/- 3.2% of body weight (range 55.8%-65.4%), from which a FFM of 41.9 +/- 6.1 kg (range 31.8 kg-51.3 kg) was obtained. Total body water in the group of 10 female subjects whose mean body weight was 42.7 +/- 4.9 kg, was 57.0 +/- 4.5% of body weight (range 52.5%-64.2%) from which a FFM of 34.0 +/- 5.1 kg (range 28.4 kg-39.4 kg) was obtained.