Comparison of commonly used procedures, including the doubly-labelled water technique, in the estimation of total energy expenditure of women with special reference to the significance of body fatness

Abstract

According to the report of the World Health Organization (1985), total energy expenditure (TEE) in human subjects can be calculated as BMR×physical activity level (PAL). However, other reports have pointed out limitations in the suggested procedure related to the % body fat of the subjects. The purpose of the present study was to evaluate the World Health Organization (1985) procedure in thirty-four healthy women with BMI 18–39kg/m 2 . BMR and TEE were measured using indirect calorimetry (BMR meas ) and the doubly-labelled water method (TEE ref ) respectively. When assessed using the doubly-labelled water and skinfold-thickness methods, the women had 34 (sd 8) and 33 (sd 6) % body fat respectively. On the basis of guidelines provided by the World Health Organization (1985), 1·64 was selected to represent the average PAL of the women. Furthermore, PAL was also assessed by means of an accelerometer (PAL acc ), heart-rate recordings (PAL HR ) and a questionnaire (PAL q ). These estimates were: PAL acc 1·71 (sd 0·17), PAL HR 1·76 (sd 0·24), PAL q 1·86 (sd 0·27). These values were lower than TEE ref /BMR ref , which was 1·98 (sd 0·21). BMR assessed using equations recommended by the World Health Organization (1985) (BMR predicted ) overestimated BMR by 594 (sd 431) kJ/24h. However, when TEE was calculated as BMR predicted ×PAL acc , BMR predicted ×PAL HR and BMR predicted ×PAL q respectively, average results were in agreement with TEE ref . Furthermore, TEE values based on BMR predicted and PAL acc , PAL HR , PAL q as well as on PAL=1·64, minus TEE ref , were significantly correlated with body fatness. When the same PAL value (1·64) was used for all subjects, this correlation was particularly strong. Thus, the World Health Organization (1985) procedure may give TEE results that are biased with respect to the body fatness of subjects.