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This study aimed to develop a regression equation to predict physical activity energy expenditure (PAEE) using accelerometry. Children aged 11-13 years were recruited and randomly assigned to validation ( n = 54) and cross-validation ( n = 25) groups. The doubly labelled water (DLW) technique was used to assess energy expenditure and accelerometers were worn by participants across the same period. A preliminary equation was developed using stepwise multiple regression analysis with sex, height, weight, body mass index, fat-free mass, fat mass and counts per minute (CPM) as independent variables. Goodness-of-fit statistics were used to select the best prediction variables. The PRESS (predicted residual error sum of squares) statistical method was used to validate the final prediction equation. The preliminary equation was cross-validated on an independent group and no significant ( p > 0.05) difference was observed in the PAEE estimated from the two methods. Independent variables of the final prediction equation (PAEE = [0.001CPM] - 0.112) accounted for 70.6% of the variance. The new equation developed to predict PAEE from accelerometry was found to be valid for use in Sri Lankan children.

Background/objectives: Young Indian adults are at greater risk of overweight/obesity due to their high energy intake and sedentary lifestyle. Their energy requirement (ER) is based on their total energy expenditure (TEE) estimated from factorial method, which possibly overestimates their basal metabolic rate (BMR) and physical activity level (PAL). This study aimed to compare the accurately measured TEE with ER in young adults. Secondarily, to compare measured with predicted BMR and guideline PAL with that obtained from questionnaire and step counts., Subjects/methods: TEE was measured in 19 male adults (18-30 years), using the doubly labeled water technique, over 14 days. Indirect calorimetry was used to measure BMR, while the PAL was estimated by (a) the ratio of measured TEE and BMR, (b) step counts over 7 days measured using tri-axial accelerometers and (c) a physical activity questionnaire (PAQ)., Results: The measured TEE (9.11 ± 1.30 MJ/d) was significantly lower than the ER using either the Indian (15.2%) or the FAO/WHO/UNU (11.9%, both p < 0.01) recommendations. The measured BMR (6.90 ± 0.65 MJ/d) was significantly lower than that predicted using the FAO/WHO/UNU equation (6.5%, p < 0.01) but not for the Indian equation. The estimated PAL from measured TEE and BMR (1.35 ± 0.18), and from accelerometers (1.33 ± 0.11) was significantly lower than PAL obtained from PAQ (1.53 ± 0.17) or the guideline of 1.53 for Indians., Conclusions: The predicted BMR and PAL guideline value was higher than that measured in young Indian adults, resulting in a ~13% lower measured TEE. This emphasizes the need to revisit the guidelines for predicting ER for this population.

Background and Objectives: Indians are more prone to develop diabetes at a younger age, with normal BMI, and this might partly be due to their higher body fat content. Increase in fat mass in the body might be because of the reduction in fat oxidizing capability. Given the fact that Indians consume high carbohydrate diets, effective fat oxidation is likely to be delayed. Simple preventive weight loss strategies like exercise or change in diet regimen are needed to reduce their body fat. This study investigated the effect of exercise with a high protein dinner on overnight thermogenesis and fat oxidation., Methods and Study Design: Nine healthy normal subjects aged 18 - 30 years participated in randomised cross over study. They underwent 6 sessions of overnight whole body indirect calorimetry on separate nights with the following experimental conditions: (i) standard (habitual) meal (ii) standard meal with exercise (iii) 20% protein meal (iv) 20% protein meal with exercise (v) 50% protein meal and (vi) 50% protein meal with exercise. Oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured overnight, from which energy expenditure, non-protein respiratory quotient (RQ), and fat oxidation were estimated., Results: The estimated marginal means of fat oxidation and energy expenditure were significantly different for protocols with exercise compared to those without exercise (p=0.02). There was no acute effect of protein on nocturnal fat or carbohydrate oxidation, with or without exercise., Conclusions: Post-dinner exercise increase nocturnal fat oxidation and energy expenditure in young active Indian men.

Background: In a previous study in pregnant American women, we reported that arginine flux and nitric oxide synthesis increased in trimester 2. More recently, we reported that Indian women do not increase arginine flux during pregnancy as their American or Jamaican counterparts do., Objective: The purpose of this study was to determine whether Indian women of childbearing age are producing less arginine and/or catabolizing more arginine and therefore have less available for anabolic pathways than do Jamaican and American women., Methods: Thirty healthy women aged 28.3 ± 0.8 y from the United States, India, and Jamaica (n = 10/group) were given 6 h primed, constant intravenous infusions of guanidino-¹⁵N₂-arginine, 5,5-²H₂-citrulline, ¹⁵N₂-ornithine, and ring-²H₅-phenylalanine, in addition to primed, oral doses of U-¹³C₆-arginine in both the fasting and postprandial states. An oral dose of deuterium oxide was also given to determine fat-free mass (FFM)., Results: Compared with American women, Indian and Jamaican women had greater ornithine fluxes (μmol · kg fat FFM⁻¹ · h⁻¹) in the fasting and postprandial states (27.3 ± 2.5 vs. 39.6 ± 3.7 and 37.2 ± 2.0, respectively, P = 0.01), indicating greater arginine catabolism. However, Jamaican women had a higher endogenous arginine flux than did Indian and American women in the fasting (66.1 ± 3.1 vs. 54.2 ± 3.1 and 56.1 ± 2.1, respectively, P = 0.01) and postprandial (53.8 ± 2.2 vs. 43.7 ± 4.9 and 42.8 ± 3.1, respectively, P = 0.06) states. As a consequence, Indian women had lower arginine bioavailability (μmol · kg FFM⁻¹ · h⁻¹) in the fasting state (42.0 ± 2.6) than did American (49.9 ± 1.3, P = 0.045) and Jamaican (55.5 ± 3.5, P = 0.004) women, as well as in the postprandial state (40.7 ± 3.5 vs. 51.8 ± 1.2 and 57.5 ± 3.2, respectively, P = 0.001)., Conclusion: Compared with American and Jamaican women, Indian women of childbearing age have a decreased arginine supply because of increased arginine catabolism without an increase in arginine flux., (© 2015 American Society for Nutrition.)

Low intakes of calcium and inadequate vitamin D status often cluster with higher prevalence rates of obesity. Consequently, there has been much interest in the mechanisms by which calcium and vitamin D could regulate body weight and adiposity. This review has focused on randomized controlled trials (RCTs) that have manipulated these nutrients and studied pathways of energy balance. Overall, there is consistent evidence that calcium and vitamin D increase whole body fat oxidation after single and multiple meals, and that calcium promotes a modest energy loss through increased faecal fat excretion. The evidence is equivocal for a greater diet-induced thermogenesis, increased lipolysis, suppression of key lipogenic enzymes, decreased hunger ratings or reduced energy/macronutrient intake. Emerging evidence suggests a potential improvement in insulin sensitivity following vitamin D that would impinge on food intake and substrate oxidation. However, the very few RCTs on supplemental vitamin D and energy balance have not explored postprandial avenues of the hormone's actions. Future efforts in this area need to define the threshold intake of these nutrients that would maximize metabolic and gastrointestinal outcomes. Such studies would provide a platform for endorsing the non-skeletal role of calcium and vitamin D in human pathophysiology., (© 2012 The Authors. obesity reviews © 2012 International Association for the Study of Obesity.)

We recently reported the lysine requirement of school-aged children living in Canada consuming a mixed diet to be 35 mg.kg(-1).d(-1). Because the majority of children in the world live on cereal-based diets in developing countries, we measured the daily lysine requirement in healthy children living in India and consuming a mostly cereal-based diet. Our objective in this study was to determine the lysine requirement in healthy, school-aged children in the developing world by using the indicator amino acid oxidation method with l-[1-(13)C] phenylalanine. Six healthy, school-aged children consumed 7 levels of lysine (5, 15, 25, 35, 50, 65, and 80 mg.kg(-1).d(-1)) each in a random order along with an amino acid mixture providing energy and protein intakes of 1.7 x resting energy expenditure and 1.5 g.kg(-1).d(-1), respectively. The mean lysine requirement was determined by applying a 2-phase linear regression crossover analysis on tracer oxidation (F(13)CO(2)) data, which identified a breakpoint (requirement) at minimal F(13)CO(2) in response to the graded lysine intakes. The mean lysine requirements with the upper 95% CI for children were determined to be 33.5 and 46.6 mg.kg(-1).d(-1), respectively, by breakpoint analysis of the F(13)CO(2) data. The mean lysine requirements of Indian children were almost identical to that of Canadian children (35 mg.kg(-1).d(-1)). There is no evidence for any adaptation in lysine requirements in children from developing countries such as India.

Objective: To validate questionnaire-based physical activity level (PAL) against accelerometry and a 24 h physical activity diary (24 h AD) as reference methods (Protocol 2), after validating these reference methods against the heart rate-oxygen consumption (HRVO2) method (Protocol 1)., Design: Cross-sectional study., Setting: Two villages in Andhra Pradesh state and Bangalore city, South India., Subjects: Ninety-four participants (fifty males, forty-four females) for Protocol 2; thirteen males for Protocol 1., Results: In Protocol 2, mean PAL derived from the questionnaire (1.72 (sd 0.20)) was comparable to that from the 24 h AD (1.78 (sd 0.20)) but significantly higher than the mean PAL derived from accelerometry (1.36 (sd 0.20); P < 0.001). Mean bias of PAL from the questionnaire was larger against the accelerometer (0.36) than against the 24 h AD (-0.06), but with large limits of agreement against both. Correlations of PAL from the questionnaire with that of the accelerometer (r = 0.28; P = 0.01) and the 24 h AD (r = 0.30; P = 0.006) were modest. In Protocol 1, mean PAL from the 24 h AD (1.65 (sd 0.18)) was comparable, while that from the accelerometer (1.51 (sd 0.23)) was significantly lower (P < 0.001), than mean PAL obtained from the HRVO2 method (1.69 (sd 0.21))., Conclusions: The questionnaire showed acceptable validity with the reference methods in a group with a wide range of physical activity levels. The accelerometer underestimated PAL in comparison with the HRVO2 method.

Background/objectives: To test the association between physical activity measured using accelerometer counts (Actigraph) and energy expenditure (EE) measured using the doubly labelled water (DLW) method in free-living children in India. The aim of this study was to explore the usefulness of Actigraphs in estimating EE., Subjects/methods: Total EE (TEE) was measured in 58 children aged 8-9 years over a period of 2 weeks using the DLW technique. Physical activity level (PAL) was estimated from TEE, and the basal metabolic rate was predicted from weight. Physical activity was measured simultaneously using the Actigraph accelerometers (MTI AM7164 and GT1M). TEE was also calculated from the Actigraph counts using a published equation., Results: TEE (mean: 6.6 vs 5.7 MJ, P=0.04) and Actigraph counts (counts/minute: 557 vs 465, P=0.02; total counts: 445 534 vs 354 748, P=0.004) were higher in boys than in girls. There were no significant correlations between either total Actigraph counts (r=0.15, P=0.3) or counts/minute (r=0.18, P=0.2), and TEE estimated using DLW. Similarly, there were no significant correlations between Actigraph counts and PAL (r=0.10, P=0.5; r=0.17, P=0.2, respectively). The Bland-Altman analysis showed poor agreement between TEE estimated using the DLW method and TEE derived from the Actigraph equation., Conclusions: Activity measured using Actigraph accelerometers was not related to TEE and PAL derived using the DLW technique in children in Mysore. Actigraphs may not be useful in predicting EE in this setting, but may be better used for judging activity patterns.

The objective of this study was to develop a physical activity assessment questionnaire for use in poorly educated and low socio-economic rural communities in developing countries and assess the repeatability of the measurements over a one-year duration. Physical Activity Level, as a composite measure of daily physical activity (PAL = estimated 24 hour energy expenditure / estimated basal metabolic rate) was derived from the semi-pictorial, interviewer based questionnaire assessing physical activity over the previous 1 week. PAL of both men and women was unchanged across the different seasons of the year. Correlations between the first physical activity questionnaire and the mean of at least 4 questionnaires administered during the course of one year were generally high (males: PAL 'r' = 0.69, individual domains 'r' between 0.57 and 0.82; females: PAL 'r' = 0.7, individual domains 'r' between 0.41 and 0.76, all p < 0.05). Within- individual % coefficient variations (CV) across 4 physical activity questionnaires were low for sleep duration and PAL (< 14%) but high for the other domains of physical activity (77-100%). The data, at least in this community, suggest that while within-individual variations in specific domains of physical activity may be considerable, the questionnaire that we designed can rank individuals in terms of their PAL or individual domains of physical activity fairly consistently. A single physical activity assessment using this instrument may therefore be adequate to rank individuals.

Background & Objectives: The total daily energy expenditure in patients with infectious disease is presumed to be high because of an increase in the basal metabolic rate (BMR), a reason for the weight loss observed in these patients. A reduction in daily physical activity, which may reduce the total daily energy expenditure. The aim of this study was to measure the free living total daily energy expenditure and physical activity of newly diagnosed hospitalized patients with tuberculosis using the labelled bicarbonate method., Methods: In 6 healthy volunteers and 6 patients with newly diagnosed tuberculosis, 13C labelled bicarbonate method was used to measure free living total daily energy expenditure and physical activity. The 13C sodium bicarbonate (NaH13CO3) tracer was infused intravenously over a 48 h period and breath samples collected at regular intervals to estimate expired 13CO2., Results: The patients had a 14 per cent increase in their BMR although they were not febrile at the time of measurement. However, their total daily energy expenditure was lower than that of the controls (mean value of 8.3 and 10.3 mJ/day respectively) and their physical activity level was also lower (mean 1.4 and 1.6 units respectively)., Interpretation & Conclusion: The total daily energy expenditure of afebrile patients with newly diagnosed tuberculosis is not higher than that of sedentary controls, despite an increased basal metabolic rate. It is possible that the observed weight loss in patients with tuberculosis is due to a reduced energy intake linked to anorexia associated with the disease. These findings may have relevance in nutritional treatment of chronic infections.

Objective: To evaluate a simple method that uses only a heart rate monitor to predict total energy expenditure (TEE) and physical activity level (PAL) from 24 h heart rate (HR) measurements., Design: The simple method involved the determination of the physical activity ratio (PAR) from corresponding heart rate ratios (HRR) (ratio of observed to resting HR), from an individualized calibration curve relating activities with known PAR to the HRR. Several curve fits were evaluated for this curve. The PAL was calculated from minute to minute PAR. The TEE was computed as the product of the PAL and the predicted basal metabolic rate (BMR). The accuracy of the simple method was assessed by within-subject comparisons of the simple method versus the oxygen consumption - HR method and a time and motion study., Setting: Bangalore City, India., Subjects: In all, 17 healthy male subjects between 18 and 44 years were recruited for the study., Interventions: None., Results: The simple method correlated well with both the reference methods when using a calibration curve that involved the fitting of two straight lines at low and high PAR activities, respectively, to the PAR and HRR data. The mean error in TEE, as a product of BMR and PAL, was about 1%, but with limits of agreement between the methods that were about 20% of the TEE. However, the low mean error could have been due to a canceling of errors in the determination of BMR and PAL., Conclusions: The simple method is a relatively cheap, useful technique for evaluating TEE and PAL in resource-poor situations. It may particularly be of use in epidemiological investigations where population estimates of TEE and PAL are required.

Energy deficiency is probably best measured in adults by the body mass index (BMI). Acute energy deficiency (AED) is associated with body weight loss, along with changes in body composition, as well as a reduced BMR and physical activity. Chronic energy deficiency (CED) is an inadequacy in food to which individuals adapt, at some cost. Individuals with this have never 'lost' weight: they have simply grown less. They adapt to the decreased food energy by reductions in their total energy expenditure (TEE), linked mainly to a lower body size, and to their physical activity. It seems unlikely that enhanced metabolic efficiency contributes substantially to energy saving in CED. Supplementation of energy deficient individuals is accompanied by significant fat deposition; this may have deleterious consequences. Women in many developing countries achieve a successful outcome to pregnancy in spite of being chronically undernourished. Reductions in basal metabolism and behavioural changes in the form of diminished physical activity could meet most of the extra energy needed for pregnancy. Milk energy output is maintained within the expected range in undernourished lactating mothers. Energy deficiency in children is best measured by height-for-age for stunting, and weight-for-height for wasting. Deficits in behavioural and functional parameters in children exist with undernutrition, and can be reduced by early nutritional supplementation along with the appropriate environment.

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.

Doubly labelled (2H2(18)O) water was used to determine the daily total energy expenditure (TEE) in the free living state of 6 adult, healthy, weight stable, male volunteers over a period of 21 days. The body weights of the subjects ranged from 42.3-70.4 kg. Isotope pool sizes and elimination rates were calculated from 18O and 2H enrichments in basal and daily (21 days) post dose urine samples using the multipoint slope intercept method after corrections for isotope fractionation. The physical activity level (PAL) of the subjects was also measured during the experiment as the ratio of measured TEE to measured basal metabolic rate (BMR). Simultaneous prediction of the total energy expenditure was also carried out by combining the measurements of BMR by indirect calorimetry, and daily physical activity level by 7 day recall. TEE calculated by the isotopic technique was 9.35 +/- 2.00 MJ/day, with an inter individual variation of 21.4 per cent. The measured BMRs in the subjects along with PALs obtained by recall, gave a total daily energy expenditure of 8.66 +/- 2.20 MJ/day with an inter individual variation of 25.4 per cent. The average BMR was 5.59 +/- 0.99 MJ/day and the average PAL (by recall) was 1.54 +/- 0.12. The inter individual variation of the BMR was 17.7 per cent and that of the recalled PAL was 7.9 per cent; the latter increased to 12.2 per cent when the PAL was calculated from the ratio of the measured TEE to the BMR. There was no significant differences between the methods (isotopic and predicted by BMR), although, the TEE obtained by the isotopic method was higher, by about 0.7 MJ/day, or 7.9 per cent, than the TEE predicted by BMR.

The effect of an infusion of norepinephrine (0.42 nmol.kg-1.min-1) on energy metabolism in the whole body (using indirect calorimetry and the arteriovenous forearm catheterization techniques in eight healthy young male adults. The activity of the triglyceride-fatty acid cycle, which mainly operates in nonmuscular tissues, was also assessed by measuring glycerol turnover using [2H5]glycerol (to indicate lipolysis) and indirect calorimetry (to indicate net fat oxidation). Norepinephrine increased whole body oxygen consumption by almost 10% (P < 0.01), but the estimated oxygen consumption of muscles tended to decrease. Muscle blood flow (measured by 133Xe) and forearm blood flow (measured by strain-gauge plethysmography) were not significantly affected by norepinephrine, but the rate of uptake of nonesterified fatty acids and beta-hydroxybutyrate increased severalfold (P < 0.05), whereas that of glucose did not. The activity of the triglyceride-fatty acid cycle increased fourfold after norepinephrine administration, having a marginal effect on resting energy expenditure (approximately 1.5%) but accounting for approximately 15% of the increase in whole body energy expenditure. This study provides no evidence that skeletal muscle is an important site for norepinephrine-induced thermogenesis and suggests that an increase in the activity of the triglyceride-fatty acid cycle contributes to the norepinephrine-induced increase in energy expenditure of nonmuscular tissues.

Maximal aerobic capacity (VO2max) and oxygen consumption during recovery were measured in well-nourished control subjects (C) and compared with results from chronically energy-deficient (CED) subjects in the same age range. The absolute VO2max was lower in undernourished subjects (2.5 +/- 0.1 L/min [C] v 1.8 +/- 0.1 L/min [CED]; mean +/- SEM, P < .001); however, when expressed per kilogram fat-free mass (FFM), the values were comparable. The total O2 debt was higher in the well-nourished group even when corrected for FFM differences (249.1 +/- 17.1 v 147.3 +/- 9.2 mL/kg FFM; P < .001). O2 consumption in the recovery period returned to baseline values rapidly and in a single phase in undernourished subjects. In contrast, a slow biphasic decline was observed in well-nourished control subjects. The postexercise recovery phase may be an important period during which energy-saving may occur in chronically undernourished human subjects.

Chronically undernourished patients (n = 10) undergoing elective abdominal surgery were assessed with regard to their energy expenditure and urinary nitrogen loss. These measurements were made for 1 week after the surgery, and stress factors for each parameter were computed. The responses of the chronically undernourished patients were compared to those of relatively well nourished patients (n = 10) undergoing comparable surgeries. It was found that the postoperative resting energy expenditure (REE) of the chronically undernourished patients was not significantly elevated when compared to their preoperative values (mean +/- SEM): 1210.66 +/- 88.13, 1354.91 +/- 86.61, 1215.09 +/- 89.68, and 1188.23 +/- 86.61 kcal/day preoperatively and on postoperative days 1, 4, and 8, respectively. On the other hand, the postoperative REE of the controls was significantly elevated (p < 0.05) over their baseline values: 1357.18 +/- 70.81, 1574.66 +/- 100.35, 1502.89 +/- 109.44, and 1477.23 +/- 83.52; kcal/day, respectively, for the same days. The stress factors for the controls were higher than those for the undernourished (1.16 versus 1.12, 1.11 versus 1.00, and 1.09 versus 0.98 on postoperative days 1, 4, and 8, respectively). The urinary nitrogen excretion in both groups (for the 4 days) was not significantly elevated over baseline (6.23 +/- 0.87, 7.72 +/- 0.71, 8.36 +/- 0.87, and 8.04 +/- 1.56 grams/day in the undernourished; and 7.59 +/- 1.03, 9.57 +/- 1.33, 9.49 +/- 1.03, and 8.67 +/- 0.76 grams/day in the controls. The stress factors for nitrogen excretion were slightly higher in the undernourished group.(ABSTRACT TRUNCATED AT 250 WORDS)

The sympatho-adrenal system is involved in the regulation of energy metabolism and responds to changes in energy intake. Energy restriction diminishes the sympathetic drive while overfeeding increases it. Chronically energy deficient subjects show an enhanced alpha and beta receptor responsiveness, which may be of a denervation type, associated with the reduced sympathetic activity that results from the decrease in dietary energy intake. The reduced basal metabolism of energy restricted subjects is partly attributable to the decrease in sympathetic activity. Chronically energy deficient individuals also show a suppressed thermogenic response to infusions of adrenergic agonists such as noradrenaline. Although sympathetic activity plays a modulating role in the energy homeostasis of the chronically energy deficient, it is not possible to explain seasonal fluctuations in energy balance.