Total energy expenditure & physical activity level in chronically energy deficient Indian males measured by the doubly labelled water technique.

Total energy expenditure (TEE) and basal metabolic rate (BMR) in the free-living state were measured in healthy south Indians, by the doubly labelled water (DLW) method. From these measurements, estimates of physical activity level (PAL) could be calculated. A total of 18 subjects were studied in 3 groups of 6 subjects each: Group I (urban controls), Group II (urban slum, chronically undernourished) and Group III (rural). The urban slum recruits were chronically energy deficient (CED), and had a low BMI (average 17.0 kg/m2), while the rural subjects had an average BMI of 18.1 kg/m2. The TEE measured by the doubly labelled water technique was 11.2, 7.1 and 12.2 MJ/day for Groups I, II and III respectively. The TEE was significantly lower in the urban CED group as obtained by the one way ANOVA. The estimates of TEE by the DLW technique were compared with estimates made by whole body calorimetry, in the urban groups of subjects. The TEE obtained by calorimetry was 10.3 +/- 1.6 and 7.3 +/- 0.2 MJ/day in Groups I and II respectively. There were no significant differences between the TEE measured by the two methods, in both the groups. The two methods also correlated well, and the mean difference between the methods, in both groups was -0.5 +/- 1.1 MJ/day, which was about 6 per cent of the value of TEE measured by the DLW method. The calculated PAL (by using TEE measured by DLW/BMR) was 1.79, 1.54 and 1.90 for Groups I, II and III respectively. The results showed that the activity of chronically energy deficient subjects, in urban slums, was reduced, and that this may be their method of conserving energy to maintain a stable body weight. Rural males had a high activity level, even though they had a low BMI.