Validity of predictive equations for total energy expenditure against doubly labeled water.

Variations in physical activity energy expenditure can make accurate prediction of total energy expenditure (TEE) challenging. The purpose of the present study was to determine the accuracy of available equations to predict TEE in individuals varying in physical activity (PA) levels. TEE was measured by DLW in 56 adults varying in PA levels which were monitored by accelerometry. Ten different models were used to predict TEE and their accuracy and precision were evaluated, considering the effect of sex and PA. The models generally underestimated the TEE in this population. An equation published by Plucker was the most accurate in predicting the TEE in our entire sample. The Pontzer and Vinken models were the most accurate for those with lower PA levels. Despite the levels of accuracy of some equations, there were sizable errors (low precision) at an individual level. Future studies are needed to develop and validate these equations.

Validity of dietary assessment methods compared with doubly labeled water in children: A systematic review and meta-analysis.

OBJECTIVES: We aimed to validate dietary assessment methods against the gold standard, doubly labeled water (DLW), for estimating total energy intake (TEI). METHODS: PubMed, Scopus, Web of Science, and Google Scholar databases were searched until May 2023. Inclusion criteria encompassed studies involving participants aged 1-18 years, employing dietary assessment methods like food records, dietary histories, food frequency questionnaire (FFQ), or 24-h recalls estimating TEI alongside DLW to measure total energy expenditure (TEE). Data were pooled using random-effects meta-analysis models. RESULTS: Thirty-three studies were identified, with sample sizes ranging from 9 to 118 participants. Meta-analysis of 22 studies identified underestimation of TEI (mean difference [MD] = -262.9 kcal/day [95% CI: -380.0, -145.8]; I2 = 93.55%) for food records compared with TEE estimated by DLW. Other dietary assessment methods, including food recalls (n = 9) (MD = 54.2 kcal/day [95% CI: -19.8, 128.1]; I2 = 49.62%), FFQ (n = 7) (MD = 44.5 kcal/day [95% CI: -317.8, 406.8]; I2 = 94.94%), and diet history (n = 3) (MD = -130.8 kcal/day [95% CI: -455.8, 194.1]; I2 = 77.48%), showed no significant differences in TEI compared with DLW-estimated TEE. All studies were of high quality. CONCLUSION: Food records may underestimate TEI, yet additional research is needed to identify the most accurate methods for assessing children's dietary intake.

Biomarker-assessed total energy intake and its cohort study association with all-cause mortality in postmenopausal females.

BACKGROUND: The association of total energy intake (EI) with all-cause mortality is uncertain as are the dependencies of this association on age and weight change history. OBJECTIVES: To identify an EI biomarker suitable for use in epidemiologic association studies and to study EI associations with total mortality in a Women's Health Initiative (WHI) cohort of postmenopausal United States females (1993-present). METHODS: EI biomarkers were developed based on doubly labeled water (DLW) total energy expenditure (TEE) and weight variation during the 2-wk DLW protocol period using the energy balance method in an embedded feeding study (n = 153). This along with 2 earlier WHI nutrition biomarker studies having TEE assessments (n = 1131 total), with 14.6 y (median) follow-up, constituted a prospective cohort for the study of EI and all-cause mortality. RESULTS: An empirical biomarker for log(EI) was developed that had a correlation of 0.73 with log(feeding study-consumed EI). The overall association between EI and mortality was nonsignificant. The association, however, depended on age (P = 0.009), with lower EI associated with lower mortality at younger ages, and also on preceding weight change history (P = 0.03). Among participants with stable or increasing weight, mortality hazard ratios (95% confidence intervals [CIs]) for a 12% lower EI were 0.66 (95% CI: 0.51, 0.87) at age 60, 0.84 (95% CI: 0.72, 0.98) at age 70, and 1.06 (95% CI: 0.87, 1.29) at age 80. Corresponding values for participants having preceding weight loss were 0.83 (95% CI: 0.61, 1.12) at age 60, 1.05 (95% CI: 0.87, 1.26) at age 70, and 1.33 (95% CI: 1.08, 1.63) at age 80. A previously considered EI biomarker, using a theoretical model for variation in body fat and fat-free mass components over time, gave similar results following rescaling. CONCLUSIONS: Lower EI is associated with lower all-cause mortality among younger postmenopausal females with stable or increasing weight and with higher mortality among older females with weight loss. This study was registered with clinicaltrials.gov as NCT00000611.

Development and validation of age-specific predictive equations for total energy expenditure and physical activity levels for older adults.

BACKGROUND: Predicting energy requirements for older adults is compromised by the underpinning data being extrapolated from younger adults. OBJECTIVES: To generate and validate new total energy expenditure (TEE) predictive equations specifically for older adults using readily available measures (age, weight, height) and to generate and test new physical activity level (PAL) values derived from 1) reference method of indirect calorimetry and 2) predictive equations in adults aged ≥65 y. METHODS: TEE derived from "gold standard" methods from n = 1657 (n = 1019 females, age range 65-90 y), was used to generate PAL values. PAL ranged 1.28-2.05 for males and 1.26-2.06 for females. Physical activity (PA) coefficients were also estimated and categorized (inactive to very active) from population means. Nonlinear regression was used to develop prediction equations for estimating TEE. Double cross-validation in a randomized, sex-stratified, age-matched 50:50 split, and leave one out cross-validation were performed. Comparisons were made with existing equations. RESULTS: Equations predicting TEE using the Institute of Medicine method are as follows: For males, TEE = -5680.17 - 17.50 × age (years) + PA coefficient × (6.96 × weight [kilograms] + 44.21 × height [centimeters]) + 1.13 × resting metabolic rate (RMR) (kilojoule/day). For females, TEE = -5290.72 - 8.38 × age (years) + PA coefficient × (9.77 × weight [kilograms] + 41.51 × height [centimeters]) + 1.05 × RMR (kilojoule/day), where PA coefficient values range from 1 (inactive) to 1.51 (highly active) in males and 1 to 1.44 in females respectively. Predictive performance for TEE from anthropometric variables and population mean PA was moderate with limits of agreement approximately ±30%. This improved to ±20% if PA was adjusted for activity category (inactive, low active, active, and very active). Where RMR was included as a predictor variable, the performance improved further to ±10% with a median absolute prediction error of approximately 4%. CONCLUSIONS: These new TEE prediction equations require only simple anthropometric data and are accurate and reproducible at a group level while performing better than existing equations. Substantial individual variability in PAL in older adults is the major source of variation when applied at an individual level.

Assessment of Cardiorespiratory and Metabolic Contributions in an Extreme Intensity CrossFit® Benchmark Workout.

Our purpose was to characterize the oxygen uptake kinetics (VO2), energy systems contributions and total energy expenditure during a CrossFit® benchmark workout performed in the extreme intensity domain. Fourteen highly trained male CrossFitters, aged 28.3 ± 5.4 years, with height 177.8 ± 9.4 cm, body mass 87.9 ± 10.5 kg and 5.6 ± 1.8 years of training experience, performed the Isabel workout at maximal exertion. Cardiorespiratory variables were measured at baseline, during exercise and the recovery period, with blood lactate and glucose concentrations, including the ratings of perceived exertion, measured pre- and post-workout. The Isabel workout was 117 ± 10 s in duration and the VO2 peak was 47.2 ± 4.7 mL·kg-1·min-1, the primary component amplitude was 42.0 ± 6.0 mL·kg-1·min-1, the time delay was 4.3 ± 2.2 s and the time constant was 14.2 ± 6.0 s. The accumulated VO2 (0.6 ± 0.1 vs. 4.8 ± 1.0 L·min-1) value post-workout increased substantially when compared to baseline. Oxidative phosphorylation (40%), glycolytic (45%) and phosphagen (15%) pathways contributed to the 245 ± 25 kJ total energy expenditure. Despite the short ~2 min duration of the Isabel workout, the oxygen-dependent and oxygen-independent metabolism energy contributions to the total metabolic energy release were similar. The CrossFit® Isabel requires maximal effort and the pattern of physiological demands identifies this as a highly intensive and effective workout for developing fitness and conditioning for sports.

Estimating Total Energy Expenditure to Determine Energy Requirements in Free-Living Children With Stage 3 Chronic Kidney Disease: Can a Structured Approach Help Improve Clinical Care?

OBJECTIVE: Malnutrition and obesity are complex burdensome challenges in pediatric chronic kidney disease (CKD) management that can adversely affect growth, disease progression, wellbeing, and response to treatment. Total energy expenditure (TEE) and energy requirements in children are essential for growth outcomes but are poorly defined, leaving clinical practice varied and insecure. The aims of this study were to explore a practical approach to guide prescribed nutritional interventions, using measurements of TEE, physical activity energy expenditure (PAEE), and their relationship to kidney function. DESIGN AND METHODS: In a cross-sectional prospective age-matched and sex-matched controlled study, 18 children with CKD (6-17 years, mean stage 3) and 20 healthy, age-matched, and gender-matched controls were studied. TEE and PAEE were measured using basal metabolic rate (BMR), activity diaries and doubly labeled water (healthy subjects). Results were related to estimated glomerular filtration rate (eGFR). The main outcome measure was TEE measured by different methods (factorial, doubly labeled water, and a novel device). RESULTS: Total energy expenditure and PAEE with or without adjustments for age, gender, weight, and height did not differ between the groups and was not related to eGFR. TEE ranged from 1927 ± 91 to 2330 ± 73 kcal/d; 95 ± 5 to 109 ± 5% estimated average requirement (EAR), physical activity level (PAL) 1.52 ± 0.01 to 1.71 ± 0.17, and PAEE 24 to 34% EAR. Comparisons between DLW and alternative methods in healthy children did not differ significantly, except for 2 (factorial methods and a fixed PAL; and the novel device). CONCLUSION: In clinical practice, structured approaches using supportive evidence (weight, height, BMI sds), predictive BMR or TEE values and simple questions on activity, are sufficient for most children with CKD as a starting energy prescription.

Longitudinal characteristics of physical frailty and its components in men and women post hip fracture.

BACKGROUND: Frailty is an important geriatric syndrome predicting adverse health outcomes in older adults. However, the longitudinal characteristics of frailty components in post-hip fracture patients are less understood. Adopting the Fried frailty definition, we examined the longitudinal trends and sex trajectory differences in frailty and its components over 1 year post-fracture. METHODS: Three hundred and twenty-seven hip fracture patients (162 men and 165 women with mean age 80.1 and 81.5) from Baltimore Hip Studies 7th cohort with measurements at 22 days after admission, and months 2, 6, and 12 post-fracture were analyzed. Frailty components included: grip strength, gait speed, weight, total energy expenditure, and exhaustion. Longitudinal analysis used mixed effect models. RESULTS: At baseline, men were sicker with worse cognitive status, and had higher weight and grip strength, but lower total energy expenditure than women (p < 0.001). The prevalence of frailty was 31.5%, 30.2%, and 28.2% at months 2, 6, and 12 respectively, showing no longitudinal trends or sex differences. However, its components showed substantial recovery trends over the post-fracture year after confounding adjustments, including increasing gait speed, reducing risk of exhaustion, and stabilized weight loss and energy expenditure over time. Particularly, while men's grip strength tended to remain stable over first year post surgery within patients, women's grip strength reduced significantly over time within patients. On average over time within patients, women were more active with higher energy expenditures but lower grip strength and weight than men. CONCLUSION: Significant recovery trends and sex differences were observed in frailty components during first year post-fracture. Overall frailty status did not show those trends over months 2-12 since a summary measure might obscure changes in components. Therefore, frailty components provided important multi-dimensional information on the complex recovery process of patients, indicating targets for intervention beyond the global binary measure of frailty.

Measurement of the Thermic Effect of Food in a Chinese Mixed Diet in Young People.

Objective: To determine the thermic effect of food (TEF) in a Chinese mixed diet in young people. Methods: During the study, the participants were weighed and examined for body composition every morning. The total energy expenditure (TEE) of the participants was measured by the doubly labeled water method for 7 days, and during this period, basal energy expenditure was measured by indirect calorimetry and physical activity energy expenditure was measured by an accelerometer. The value obtained by subtracting basal energy expenditure and physical activity energy expenditure from TEE was used to calculate TEF. Results: Twenty healthy young students (18-30 years; 10 male) participated in the study. The energy intake of the participants was not significantly different from the Chinese Dietary Reference Intake of energy ( P > 0.05). The percentage of energy from protein, fat and carbohydrate were all in the normal range. The intakes of fruits, milk and dietary fiber of the participants were significantly lower than those in the Chinese Dietary Guidelines ( P < 0.05). There was no significant difference in the body weight of the participants during the experiment ( P > 0.05). When adjusted for body weight, there was no significant difference in either TEE or basal energy expenditure between the male and female participants ( P > 0.05). In addition, there was no significant difference in physical activity energy expenditure and TEF between the male and female participants ( P > 0.05). The percentage of TEF in TEE was 8.73%. Conclusion: The percentage of TEF in TEE in a Chinese mixed diet in young people was significantly lower than 10% ( P < 0.001). A value of 10% is usually considered to be the TEF in mixed diets as a percentage of TEE.

Prediction of the Physical Activity Level of Community-Dwelling Older Japanese Adults with a Triaxial Accelerometer Containing a Classification Algorithm for Ambulatory and Non-Ambulatory Activities.

Accurate methods for the prediction of the total energy expenditure and physical activity level (PAL) in community-dwelling older adults have not been established. Therefore, we examined the validity of estimating the PAL using an activity monitor (Active style Pro HJA-350IT, [ASP]) and proposed correction formulae for such populations in Japan. Data for 69 Japanese community-dwelling adults aged 65 to 85 years were used. The total energy expenditure in free-living conditions was measured with the doubly labeled water method and the measured basal metabolic rate. The PAL was also estimated from metabolic equivalent (MET) values obtained with the activity monitor. Adjusted MET values were also calculated with the regression equation of Nagayoshi et al. (2019). The observed PAL was underestimated, but significantly correlated, with the PAL from the ASP. When adjusted using the Nagayoshi et al. regression equation, the PAL was overestimated. Therefore, we developed regression equations to estimate the actual PAL (Y) from the PAL obtained with the ASP for young adults (X) as follows: women: Y = 0.949 × X + 0.205, mean ± standard deviation of the prediction error = 0.00 ± 0.20; men: Y = 0.899 × X + 0.371, mean ± standard deviation of the prediction error = 0.00 ± 0.17.

Energy expenditure of southern right whales varies with body size, reproductive state and activity level.

Quantifying the energy expenditure of animals is critical to understanding the cost of anthropogenic disturbance relative to their overall energy requirements. We used novel drone focal follows (776 follows, 185 individuals) and aerial photogrammetry (5372 measurements, 791 individuals) to measure the respiration rate and body condition loss of southern right whales (Eubalaena australis) on a breeding ground in Australia. Respiration rates were converted to oxygen consumption rate and field metabolic rate (FMR) using published bioenergetic models. The intra-seasonal loss in body condition of different reproductive classes (calves, juveniles, adults, pregnant and lactating females) was converted to blubber energy loss and total energy expenditure (TEE). Using these two metrics, we tested the effects of body size, reproductive state and activity level on right whale energy expenditure. Respiration rates and mass-specific FMR decreased exponentially with an increase in body size, as expected based on allometric scaling. FMR increased curvilinearly with an increase in swim speed, probably as a result of increased drag and increased locomotion costs. Respiration rates and FMR were 44% higher for pregnant and lactating females compared with those of adults, suggesting significant costs of fetal maintenance and milk production, respectively. The estimated FMR of adults based on their respiration rates corresponded well with the estimated TEE based on body condition loss. The rate of decline in body condition of pregnant and lactating females was considerably higher than expected based on respiration rates, which probably reflects the milk energy transfer from mothers to calves, which is not reflected in their FMR.

Total energy expenditure of collision team sports players measured using doubly labeled water: a systematic review.

PURPOSE: Total energy expenditure (TEE) is crucial for energy balance and recovery in athletes who participate in collision team sports with high training volumes. This study aimed to review the existing evidence on TEE measured using the doubly labeled water (DLW) technique in soccer, basketball, and rugby players. Furthermore, this systematic review summarized the training volume, match details during the measurement period, and body composition of the athletes. METHODS: This systematic review used the PubMed, Science Direct, Web of Science, and Embase databases. Only articles presenting objectively measured data on the TEE of adolescent and adult collision team sports players were included, as measured using the DLW method. The measurement period, training, match information, and body composition data were also obtained. The search strategy identified 1497 articles, of which 13 met the selection criteria. RESULTS: The 13 studies included four rugby players, six soccer players, and three basketball players; six of the 13 studies involved young players. The TEE measured using the DLW method was 3862.3-5783.9 kcal/day for rugby, 2859-3586 kcal/day for soccer, and 4006-4921 kcal/day for basketball players. CONCLUSION: The TEE of collision sports players varies depending on the training or match load, body composition, and measurement period. Individual approaches to nutritional prescriptions for collision sports players should also account for different periods, anthropometric profiles, training, and game loads. This review provides evidence for developing nutritional guidelines to optimize the recovery and performance of collision team players.

Macadamia nut effects on cardiometabolic risk factors: a randomised trial.

We sought to examine the effects of daily consumption of macadamia nuts on body weight and composition, plasma lipids and glycaemic parameters in a free-living environment in overweight and obese adults at elevated cardiometabolic risk. Utilising a randomised cross-over design, thirty-five adults with abdominal obesity consumed their usual diet plus macadamia nuts (~15 % of daily calories) for 8 weeks (intervention) and their usual diet without nuts for 8 weeks (control), with a 2-week washout. Body composition was determined by bioelectrical impedance; dietary intake was assessed with 24-h dietary recalls. Consumption of macadamia nuts led to increased total fat and MUFA intake while SFA intake was unaltered. With mixed model regression analysis, no significant changes in mean weight, BMI, waist circumference, percent body fat or glycaemic parameters, and non-significant reductions in plasma total cholesterol of 2⋅1 % (-4⋅3 mg/dl; 95 % CI -14⋅8, 6⋅1) and low-density lipoprotein (LDL-C) of 4 % (-4⋅7 mg/dl; 95 % CI -14⋅3, 4⋅8) were observed. Cholesterol-lowering effects were modified by adiposity: greater lipid lowering occurred in those with overweight v. obesity, and in those with less than the median percent body fat. Daily consumption of macadamia nuts does not lead to gains in weight or body fat under free-living conditions in overweight or obese adults; non-significant cholesterol lowering occurred without altering saturated fat intake of similar magnitude to cholesterol lowering seen with other nuts. Clinical Trial Registry Number and Website: NCT03801837 https://clinicaltrials.gov/ct2/show/NCT03801837?term = macadamia + nut&draw = 2&rank = 1.

Total Energy Expenditure in Healthy Ambulatory Older Adults Aged ≥80 Years: A Doubly Labelled Water Study.

INTRODUCTION: The life expectancy of older adults continues to increase; however, knowledge regarding their total energy requirements is lacking. This study aimed to compare the total energy expenditure (TEE) of older adults ≥80 years measured using doubly labelled water (DLW), with estimated TEE. The hypothesis was that the Mifflin, Ikeda, and Livingston equations will more closely estimate energy requirements than the commonly used Schofield equation. METHODS: Resting metabolic rate (RMR) and TEE were measured using the reference methods of indirect calorimetry and DLW, respectively. Bland-Altman plots compared measured RMR and TEE with predicted RMR using equations (Mifflin, Ikeda, Livingston, Schofield) and predicted TEE (predicted RMR × physical activity level). RESULTS: Twenty-one older adults (age range 80.7-90.1 years, BMI 26.1 ± 5.5 kg/m2) were included. The Schofield equation demonstrated the greatest bias from measured RMR, overestimating approximately up to double the mean difference (865 ± 662 kJ/day) compared with the three other equations. The Schofield equation exhibited the greatest bias (overestimation of 641 ± 1,066 kJ/day) compared with measured TEE. The other three equations underestimated TEE, with the least bias from Ikeda (37 ± 1,103 kJ/day), followed by Livingston (251 ± 1,108 kJ/day), and Mifflin (354 ± 1,140 kJ/day). Data are mean ± SD. CONCLUSIONS: In older adults ≥80 years, the Ikeda, Mifflin, and Livingston equations provide closer estimates of TEE than the widely used Schofield equation. The development of nutrition guidelines therefore should consider the utilization of equations which more accurately reflect age-specific requirements.

Resting and total energy expenditure of patients with long-chain fatty acid oxidation disorders (LC-FAODs).

The basis of medical nutrition therapy for patients with LC-FAODs is to provide adequate energy to maintain anabolism and prevent catabolism. In practice, energy needs are estimated based on formulas derived from normal populations but it is unknown if energy expenditure among patients with LC-FAODs is similar to the normal population. We measured resting energy expenditure (REE), total energy expenditure (TEE) and body composition in 31 subjects with LC-FAODs ranging in age from 7 to 64 years. Measured REE was lower than estimated REE by various prediction equations and measured TEE was lower than estimated TEE. It is possible that the lower energy expenditure based on prediction formulas from the normal population is due to differences in body composition; we compared body composition to normal data from the 2017-18 National Health and Nutrition Examination Survey (NHANES). Fat free mass and fat mass was similar between subjects with an LC-FAOD and NHANES normal data suggesting no difference in body composition. We then compared measured REE and TEE to normal published data from the Dietary Reference Intakes (DRI). Measured REE and TEE were significantly lower among subjects with LC-FAODs compared to normal published energy expenditure data. Our results suggests patients with a LC-FAOD exhibit a lower REE and therefore actually have a slightly lower TEE than estimated. Current prediction equations may overestimate energy expenditure of patients with a LC-FAOD.

Total energy expenditure measured by doubly labeled water method in children and adolescents: a systematic review.

Total energy expenditure (TEE) is essential for understanding the growth, development, and physical activity of children and adolescents. This study aimed to summarize the existing evidence on TEE measured using the doubly labeled water (DLW) technique in children and adolescents aged 1-18 years. Furthermore, this review compared TEE between obese and normal-weight participants. This systematic review used the PubMed, ScienceDirect, Web of Science, and EBSCO databases. These studies were limited to those published in English between January 2000 and December 2021. Articles presenting objectively measured data on the TEE of children and adolescents aged 1-18 years measured using the DLW method were included. Physical activity level (PAL; TEE/basal metabolic rate [BMR]) and BMR data were also obtained. The search strategy identified 2,351 articles, of which 63 (n=4,283 children and adolescents; 45.4% male) met the selection criteria. The participants in the 10 studies were overweight or obese (n=413). In our study, TEE increased in male and female participants aged 1-18 years. PAL increased with age in males (y=0.0272x+1.3887, r2=0.511) and females (y=0.0199x+1.401, r2=0.335), and the slope of PAL with age did not differ between males and females. The TEE of obese and overweight participants was higher than that of normal-weight participants, but the slope of TEE did not differ between normal-weight (y=132.99x+702.24, r2=0.877) and obese individuals (y=136.18x+1,037.9, r2=0.842). In conclusion, this review provides convincing evidence that daily TEE progressively increases with growth in males and females aged 1-18 years.

[Contemporary approaches to the assessment of energy intake and energy expenditure in athletes].

Assessment and interpreting of the energy expenditure (EE) in highly skilled athletes are important components of an effective training and performance prediction. Each component of EE (resting energy expenditure, thermic effect of food, and physical activity energy expenditure) is closely related to dietary patterns, the intensity and duration of physical activity, as well as a number of other factors that affect the functional state of athletes. Despite the importance of EE in the training process, coaches and athletes often do not take EE into account, which reduces the objectivity of assessing athletes' functional state. The purpose of this research was to summarize the recent information on the structure of EE and energy consumption in athletes. Material and methods. The search and analysis of publications was carried out using the PubMed, MEDLINE, Scopus, Web of Science, eLIBRARY databases, mainly for the last 10 years, using the search keywords: rest energy expenditure, thermic effect of food, physical activity energy expenditure, energy intake, total energy expenditure, athletes. Results. This overview includes information on the components of total energy expenditure, such as rest energy expenditure, thermic effect of food and physical activity energy expenditure, as well as generalized information on the factors affecting the variability of their values and methods for assessing one or another type of energy expenditure. International nutritional recommendations regarding the level of physical activity of athletes are systematized, as well as the advantages and disadvantages of methods for studying energy consumption and total energy expenditure are presented. Conclusion. Combined study of energy intake and energy expenditure will help athletes avoid the negative impact of energy deficiency on performance, and the correct construction of the training process with the maintenance of adequate energy consumption will have a positive impact on the performance and recovery processes after intensive physical exertion.

Determining total energy expenditure in 3-6-year-old Japanese pre-school children using the doubly labeled water method.

The doubly labeled water (DLW, 2H218O) method for calculating the total production of CO2 over several days is currently considered to be the most accurate technique for the measurement of total energy expenditure (TEE), and the results obtained using this method have been used to review energy requirements. Presently, there is limited data available on TEE in Japanese children. The objective of this study was to assess the TEE in pre-school Japanese children using the DLW method. We used a cross-sectional population of 140 children (69 boys and 71 girls) aged 3-6 years. TEE was measured using the DLW method over 8 days under free-living conditions. The average weights (kg) of the boys and girls were 15.6 ± 2.5 and 15.0 ± 2.1 for the 3-4 years old and 19.8 ± 3.8 and 19.6 ± 2.7 for the 5-6 years old, respectively. The corresponding TEE (kcal/day) was 1260.9 ± 357.8 and 1265.2 ± 408.0, and 1682.3 ± 489.0 and 1693.1 ± 473.3, respectively, showing a significant difference with respect to age. Furthermore, TEE per body weight (kcal/kg/day) was 83.2 ± 29.2 and 84.9 ± 26.6, and 85.4 ± 23.2 and 86.7 ± 22.6, respectively. However, when TEE was adjusted for body weight or fat-free mass, there were no age or sex differences. We conclude that in Japanese children, TEE in those aged 3-4 years was similar to the current Ministry of Health recommendations. However, TEE in children aged 5-6 years was slightly higher than the recommendations. Based on these findings, the present results obtained from a large number of participants will provide valuable reference data for Japanese children.

Relationship between Measured Aerobic Capacity and Total Energy Expenditure Obtained by the Doubly Labeled Water Method in Community-Dwelling, Healthy Adults Aged 81-94 Years.

The doubly labeled water method is a gold-standard method for the measurement of total energy expenditure in daily life. We aimed to identify the relationship between measured aerobic capacity and total energy expenditure, activity energy expenditure, or physical activity level using the doubly labeled water method in adults of advanced old age. A total of 12 physically independent older adults (10 men and 2 women), aged 81-94 years, participated in this study. The aerobic capacity was evaluated according to the lactate threshold. Total energy expenditure under free-living conditions was assessed using the doubly labeled water method, and self-reported physical activity was obtained using the Japanese version of the International Physical Activity Questionnaire. The lactate threshold was significantly positively correlated with total energy expenditure, activity energy expenditure, and physical activity level after adjusting for age and sex. We found that the aerobic capacity of the lactate threshold was positively and independently correlated with total energy expenditure, activity energy expenditure, or physical activity level. The present results suggest that maintaining aerobic capacity is an important factor in preventing frailty, although further research is required.

Doubly labelled water for determining total energy expenditure in adult critically ill and acute care hospitalized inpatients: A scoping review.

BACKGROUND & AIMS: Doubly labelled water (DLW) is considered the reference standard method of measuring total energy expenditure (TEE), but there is limited information on its use in the Intensive Care Unit (ICU) and acute care setting. This scoping review aims to systematically summarize the available literature on TEE measured using DLW in these contexts. METHODS: Four online databases (MEDLINE, Embase, Emcare and CINAHL) were searched up to Dec 12, 2020. Studies in English were included if they measured TEE using DLW in adults in the ICU and/or acute care setting. Key considerations, concerns and practical recommendations were identified and qualitatively synthesized. RESULTS: The search retrieved 7582 studies and nine studies were included; one in the ICU and eight in the acute care setting. TEE was measured over 7-15-days, in predominantly clinically stable patients. DLW measurements were not commenced until four days post admission or surgery in one study and following a 10-14-day stabilization period on parenteral nutrition (PN) in three studies. Variable dosages of isotopes were administered, and several equations used to calculate TEE. Four main considerations were identified with the use of DLW in these settings: variation in background isotopic abundance; excess isotopes leaving body water as carbon dioxide or water; fluctuations in rates of isotope elimination and costs. CONCLUSION: A stabilization period on intravenous fluid and PN regimens is recommended prior to DLW measurement. The DLW technique can be utilized in medically stable ICU and acute care patients, with careful considerations given to protocol design.

Reindeer herders from subarctic Finland exhibit high total energy expenditure and low energy intake during the autumn herd roundup.

OBJECTIVE: High levels of total energy expenditure (TEE, kcal/day) have been documented among numerous human populations such as tropical climate horticulturalists and high-altitude agriculturalists. However, less work has been conducted among highly physically active cold climate populations. METHODS: In October 2018, TEE was measured using the doubly labeled water (TEEDLW , N = 10) and flex-heart rate methods (TEEHR , N = 24) for 6-14 days among reindeer herders (20-62 years) in northern Finland during an especially physically demanding, but not seasonally representative, period of the year for herders-the annual reindeer herd roundup. Self-reported dietary intake was also collected during TEE measurement periods. TEE was then compared to that of hunter gatherer, farming, and market economies. RESULTS: During the herd roundup, herders expended a mean of 4183 ± 949 kcal/day as measured by the DLW method, which was not significantly different from TEEHR . Mean caloric intake was 1718 ± 709 kcal/day, and was significantly lower than TEEDLW and TEEHR (p < .001). Herder TEEDLW was significantly higher than that of hunter gatherer (p = .0014) and market (p < .0014) economy populations; however, herder TEEDLW was not different from that of farming populations (p = .91). CONCLUSION: High TEE and low caloric intake among herders reflect the extreme demands placed on herders during the annual herd round up. Although TEEDLW was similar between cold climate herders and hot climate farming populations, there are likely differences in how that TEE is comprised, reflecting the local ecologies of these populations.