A new predictive equation for resting energy expenditure in healthy individuals.

In 1229 subjects, 521 males and 708 females, with a wide range in body mass index (BMI; 13.9-40.9 kg/m2), and an age range of 7-83 years, body composition was determined by densitometry and anthropometry. The relationship between densitometrically-determined body fat percentage (BF%) and BMI, taking age and sex (males = 1, females = 0) into account, was analysed. For children aged 15 years and younger, the relationship differed from that in adults, due to the height-related increase in BMI in children. In children the BF% could be predicted by the formula BF% = 1.51 x BMI-0.70 x age - 3.6 x sex + 1.4 (R2 0.38, SE of estimate (SEE) 4.4% BF%). In adults the prediction formula was: BF% = 1.20 x BMI + 0.23 x age - 10.8 x sex - 5.4 (R2 0.79, SEE = 4.1% BF%). Internal and external cross-validation of the prediction formulas showed that they gave valid estimates of body fat in males and females at all ages. In obese subjects however, the prediction formulas slightly overestimated the BF%. The prediction error is comparable to the prediction error obtained with other methods of estimating BF%, such as skinfold thickness measurements or bioelectrical impedance.

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Body mass index as a measure of body fatness: age- and sex-specific prediction formulas.

In brief: The assessment of body composition has become an important method for determining a desirable body weight of adults and athletes. Hydrostatic weighing is a popular and valid method, but it is often not feasible for the clinical setting or for mass testing; thus, anthropometry has become the preferred method. This article reviews the scientific basis for generalized body composition prediction equations and provides methods for evaluating body composition. The authors recommend using a sum of three skinfolds (triceps, chest, and subscapula for men and triceps, abdomen, and suprailium for women) and give detailed instructions for securing accurate measurements of body fat.

Practical Assessment of Body Composition

Methods for the assessment of human body composition: traditional and new.

0.42-1.25 kcal/kg per day; P,.001) and 0.69 (95% CI, 0.25-1.12 kcal/kg day; P = .002) for activity, and 0.77 (95% CI, 0.18-1.36 mL/kg per minute; P = .01) and 1.34 (95% CI, 0.72-1.96 mL/kg per minute; P,.001) for VO2peak for the lifestyle and structured activity groups, respectively. There were significant and comparable reductions in systolic blood pressure (˛3.63 [95% CI, ˛5.54 to ˛1.72 mm Hg; P,.001] and ˛3.26 [95% CI, ˛5.26 to ˛1.25 mm Hg; P = .002]) and diastolic blood pressure (˛5.38 [95% CI, ˛6.90 to ˛3.86 mm Hg; P,.001] and ˛5.14 [95% CI, ˛6.73 to ˛3.54 mm Hg; P,.001) for the lifestyle and structured activity groups, respectively. Neither group significantly changed their weight (˛0.05 [95% CI, ˛1.05 to 0.96 kg; P = .93] and 0.69 [95% CI, ˛0.37 to 1.74 kg; P = .20]), but each group significantly reduced their percentage of body fat (˛2.39% [95% CI, ˛2.92% to ˛1.85%; P,.001] and ˛1.85% [95% CI, ˛2.41% to ˛1.28%; P,.001]) in the lifestyle and structured activity groups, respectively.

Comparison of Lifestyle and Structured Interventions to Increase Physical Activity and Cardiorespiratory Fitness

1. Skinfold thickness, body circumferences and body density were measured in samples of 308 and ninety-five adult men ranging in age from 18 to 61 years. 2. Using the sample of 308 men, multiple regression equations were calculated to estimate body density using either the quadratic or log form of the sum of skinfolds, in combination with age, waist and forearm circumference. 3. The multiple correlations for the equations exceeded 0.90 with standard errors of approximately +/- 0.0073 g/ml. 4. The regression equations were cross validated on the second sample of ninety-five men. The correlations between predicted and laboratory-determined body density exceeded 0.90 with standard errors of approximately 0.0077 g/ml. 5. The regression equations were shown to be valid for adult men varying in age and fatness.

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M L Pollock

Papers

Generalized equations for predicting body density of men