scholarly journals Quantifying the free living energy exchanges of Arctic ungulates with stable isotopes

Rangifer ◽  
2000 ◽  
Vol 20 (2-3) ◽  
pp. 59 ◽  
Author(s):  
Paul Haggarty
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Energy Requirement ◽  
Ecological Impact ◽  
The Arctic ◽  
Unknown Parameters ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Energy Exchanges ◽  
Free Ranging

When natural diets meet an animal's requirement for energy, other essential nutrients will usually be supplied in amounts at least sufficient for survival. Knowledge of the energy requirements of free ranging species under typical conditions are important in assessing both their nutritional needs and their ecological impact. The doubly labelled water (DLW) method is currently the most promising objective field methodology for estimating free living energy expenditure but expenditure is only equal to the energy requirement when an animal is in energy balance. Reproduction and seasonal cycles of fat deposition and utilization represent significant components of the energy budget of arctic ungulates but the information gained in the course of a typical DLW study may be used to estimate processes such as milk output and fat storage and mobilization in order to predict requirements from expenditure. The DLW method has been exhaustively validated under highly controlled conditions and the introduction of innovations such as faecal sampling for the estimation of body water isotopic enrichment, the availability of appropriate correction factors and stoichiometrics for known sources of error, and iterative calculation of unknown parameters, have produced a methodology suitable for use in truly free ranging species. The few studies carried out so far in arctic ungulates indicate that previous predictions have generally underestimated the true level of expenditure, that there is considerable between animal variation in the level of expenditure and that this is largely determined by physical activity. The disadvantages of the DLW methodology are that it remains expensive and the isotope analysis is technically demanding. Furthermore, although DLW can provide an accurate value for free living energy expenditure, it is often important to have information on the individual components of expenditure, for example the relative contribution of physical activity and thermoregulatory thermogenesis, in order to interpret the values for overall expenditure. For these reasons the most valuable use of the DLW method in the field may be to validate factorial models and other approaches so that they may be used with confidence. Additional important information on the energy exchanges of free ranging animals may be obtained from other stable isotope methodologies. In addition to the use of the isotopes 2H and lsO in the DLW method, natural variations in the abundance of "C and 15N in the arctic environment may be exploited to study diet selection in truly free living arctic ungulates.

scholarly journals Evaluations of Actiheart, IDEEA® and RT3 monitors for estimating activity energy expenditure in free-living women

2013 ◽  
Vol 2 ◽  
Author(s):  
Marie Löf ◽  
Hanna Henriksson ◽  
Elisabet Forsum
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Living Conditions ◽  
Reproductive Age ◽  
Women Of Reproductive Age ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Further Development ◽  
Activity Energy ◽  
Free Living Conditions

AbstractActivity energy expenditure (AEE) during free-living conditions can be assessed using devices based on different principles. To make proper comparisons of different devices' capacities to assess AEE, they should be evaluated in the same population. Thus, in the present study we evaluated, in the same group of subjects, the ability of three devices to assess AEE in groups and individuals during free-living conditions. In twenty women, AEE was assessed using RT3 (three-axial accelerometry) (AEERT3), Actiheart (a combination of heart rate and accelerometry) (AEEActi) and IDEEA (a multi-accelerometer system) (AEEIDEEA). Reference AEE (AEEref) was assessed using the doubly labelled water method and indirect calorimetry. Average AEEActi was 5760 kJ per 24 h and not significantly different from AEEref (5020 kJ per 24 h). On average, AEERT3 and AEEIDEEA were 2010 and 1750 kJ per 24 h lower than AEEref, respectively (P < 0·001). The limits of agreement (± 2 sd) were 2940 (Actiheart), 1820 (RT3) and 2650 (IDEEA) kJ per 24 h. The variance for AEERT3 was lower than for AEEActi (P = 0·006). The RT3 classified 60 % of the women in the correct activity category while the corresponding value for IDEEA and Actiheart was 30 %. In conclusion, the Actiheart may be useful for groups and the RT3 for individuals while the IDEEA requires further development. The results are likely to be relevant for a large proportion of Western women of reproductive age and demonstrate that the procedure selected to assess physical activity can greatly influence the possibilities to uncover important aspects regarding interactions between physical activity, diet and health.

The Actiheart in Adolescents: A Doubly Labelled Water Validation

2012 ◽  
Vol 24 (4) ◽  
pp. 589-602 ◽  
Author(s):  
Nerissa Campbell ◽  
Harry Prapavessis ◽  
Casey Gray ◽  
Erin McGowan ◽  
Elaine Rush ◽  
...  
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Resting Energy Expenditure ◽  
Equation Modeling ◽  
Physical Activity Energy Expenditure ◽  
Limits Of Agreement ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Future Work ◽  
Activity Energy

Background/Objective: This study investigated the validity of the Actiheart device for estimating free-living physical activity energy expenditure (PAEE) in adolescents. Subjects/Methods: Total energy expenditure (TEE) was measured in eighteen Canadian adolescents, aged 15–18 years, by DLW. Physical activity energy expenditure was calculated as 0.9 X TEE minus resting energy expenditure, assuming 10% for the thermic effect of feeding. Participants wore the chest mounted Actiheart device which records simultaneously minute-by-minute acceleration (ACC) and heart rate (HR). Using both children and adult branched equation modeling, derived from laboratory-based activity, PAEE was estimated from the ACC and HR data. Linear regression analyses examined the association between PAEE derived from the Actiheart and DLW method where DLW PAEE served as the dependent variable. Measurement of agreement between the two methods was analyzed using the Bland-Altman procedure. Results: A nonsignificant association was found between the children derived Actiheart and DLW PAEE values (R = .23, R2 = .05, p = .36); whereas a significant association was found between the adult derived Actiheart and DLW PAEE values (R = .53, R2 = .29, p < .05). Both the children and adult equation models lead to overestimations of PAEE by the Actiheart compared with the DLW method, by a mean difference of 31.42 kcal·kg−·d−1 (95% limits of agreement: −45.70 to −17.15 kcal·kg−1·d−1 and 9.80 kcal·kg−1·d−1 (95% limits of agreement: −21.22-1.72 kcal·kg−1·d−1), respectively. Conclusion: There is relatively poor measurement of agreement between the Actiheart and DLW for assessing free-living PAEE in adolescents. Future work should develop group based branched equation models specifically for adolescents to improve the utility of the device in this population.

scholarly journals Evaluation of Actiheart and a 7 d activity diary for estimating free-living total and activity energy expenditure using criterion methods in 1·5- and 3-year-old children

2014 ◽  
Vol 111 (10) ◽  
pp. 1830-1840 ◽  
Author(s):  
Hanna Henriksson ◽  
Elisabet Forsum ◽  
Marie Löf
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Fat Mass ◽  
Fat Free Mass ◽  
Activity Levels ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Metabolic Equivalent ◽  
Activity Diary ◽  
Activity Energy

Accurate and easy-to-use methods to assess free-living energy expenditure in response to physical activity in young children are scarce. In the present study, we evaluated the capacity of (1) 4 d recordings obtained using the Actiheart (mean heart rate (mHR) and mean activity counts (mAC)) to provide assessments of total energy expenditure (TEE) and activity energy expenditure (AEE) and (2) a 7 d activity diary to provide assessments of physical activity levels (PAL) using three sets of metabolic equivalent (MET) values (PALTorun, PALAdolphand PALAinsworth) in forty-four and thirty-one healthy Swedish children aged 1·5 and 3 years, respectively. Reference TEE, PALrefand AEE were measured using criterion methods, i.e. the doubly labelled water method and indirect calorimetry. At 1·5 years of age, mHR explained 8 % (P= 0·006) of the variation in TEE above that explained by fat mass and fat-free mass. At 3 years of age, mHR and mAC explained 8 (P= 0·004) and 6 (P= 0·03) % of the variation in TEE and AEE, respectively, above that explained by fat mass and fat-free mass. At 1·5 and 3 years of age, average PALAinsworthvalues were 1·44 and 1·59, respectively, and not significantly different from PALrefvalues (1·39 and 1·61, respectively). By contrast, average PALTorun(1·5 and 3 years) and PALAdolph(3 years) values were lower (P< 0·05) than the corresponding PALrefvalues. In conclusion, at both ages, Actiheart recordings explained a small but significant fraction of free-living energy expenditure above that explained by body composition variables, and our activity diary produced mean PAL values in agreement with reference values when using MET values published by Ainsworth.

scholarly journals Energy expenditure in disease: time to revisit?

2000 ◽  
Vol 59 (2) ◽  
pp. 199-207 ◽  
Author(s):  
Eileen R. Gibney
Keyword(s):  
Energy Expenditure ◽  
Total Energy ◽  
Energy Requirement ◽  
Total Energy Expenditure ◽  
Energy Requirements ◽  
Direct Result ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Tracer Techniques ◽  
Urea Method

Knowledge of energy expenditure is especially important in disease, and may in fact help in the understanding of the pathophysiology of wasting associated with disease. Energy requirements in a clinical setting are often ‘prescribed’ by health professionals, either directly through enteral or parenteral feeding, or perhaps controlled through a hospital diet. Studies initially suggested an increase in energy expenditure, and thus energy requirements, as a direct result of an increase in basal metabolic rate often seen in disease. However, many problems exist in the measurement of BMR in a disease situation, due to the effects of drugs, clinical practice, feeding or possibly anxiety either as a cause of the disease or the measurement itself. These problems could in themselves contribute to the rise in metabolism seen in disease. More recently, however, with the use of tracer techniques such as doubly-labelled water and the bicarbonate–urea method, more accurate estimates of energy expenditure, and thus energy requirements, have been made. Some such measurements have in fact shown that even with an elevated BMR, free-living total energy expenditure can in fact be reduced in many disease situations, suggesting a reduced rather than an increased energy requirement. The present review investigates measurements of total energy expenditure in disease to explore the hypothesis that energy expenditure in disease, even with an elevated BMR, can in fact be reduced due to a concurrent reduction in physical activity.

scholarly journals Energy requirements of adults

2005 ◽  
Vol 8 (7a) ◽  
pp. 994-1009 ◽  
Author(s):  
Prakash Shetty
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Energy Restriction ◽  
Activity Level ◽  
Energy Requirements ◽  
Metabolic Adaptation ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Life Styles ◽  
Made In

AbstractObjectivesTo describe issues related to energy requirements of free living adults and discuss the importance of basal metabolic rate (BMR) and their relationships to total energy expenditure (TEE ) and physical activity level (PAL, derived as TEE/BMR) and to determine the influence of body weight, height, age and sex.DesignBased on a review of the literature, this paper examines the variability in BMR due to methodology, ethnicity, migration and adaptation (both metabolic and behavioural) due to changes in nutritional status. Collates and compiles data on measurements of TEE in free living healthy adults, to arrive at limits and to compare TEE of populations with different life-styles.Results and ConclusionsThe constancy of BMR and its validity as a reliable predictor of TEE in adults as well as the validity of PAL as an index of TEE adjusted for BMR and thus its use to categorise the physical activity pattern and lifestyle of an individual was confirmed. The limits of human daily energy expenditure at around 1.2×BMR and 4.5×BMR based on measurements made in free living adults have been reported in the literature. A large and robust database now exists of energy expenditure measurements obtained by the doubly labelled water method in the scientific literature and the data shows that, in general, levels of energy expenditure are similar to the recommendations for energy requirements adopted by FAO/WHO/UNU (1985). The review also confirms that metabolic adaptation to energy restriction is not an important factor that needs to be considered when recommending energy requirements for adults in developing countries.

scholarly journals Validating accelerometry-derived proxies of energy expenditure using the doubly-labelled water method in the smallest penguin species

Biology Open ◽  
2021 ◽  
pp. bio.055475
Author(s):  
G. J. Sutton ◽  
J. A. Botha ◽  
J. R. Speakman ◽  
J. P. Y. Arnould
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Energy Use ◽  
Travel Speed ◽  
Specific Energy Expenditure ◽  
Doubly Labelled Water ◽  
Data Collection And Analysis ◽  
Behavioural Patterns ◽  
Free Ranging ◽  
The Relationship

Understanding energy use is central to understanding an animal's physiological and behavioural ecology. However, directly measuring energy expenditure in free-ranging animals is inherently difficult. The doubly-labelled water (DLW) method is widely used to investigate energy expenditure in a range of taxa. Although reliable, DLW data collection and analysis is both financially costly and time consuming. Dynamic body acceleration (e.g. VeDBA) calculated from animal-borne accelerometers has been used to determine behavioural patterns, and is increasingly being used as a proxy for energy expenditure. Still its performance as a proxy for energy expenditure in free-ranging animals is not well established and requires validation against established methods. In the present study, the relationship between VeDBA and the at-sea metabolic rate calculated from DLW was investigated in little penguins (Eudyptula minor) using three approaches. Both in a simple correlation and activity-specific approaches were shown to be good predictors of at-sea metabolic rate. The third approach using activity-specific energy expenditure values obtained from literature did not accurately calculate the energy expended by individuals. However, all three approaches were significantly strengthened by the addition of mean horizontal travel speed. These results provide validation for the use of accelerometry as a proxy for energy expenditure and show how energy expenditure may be influenced by both individual behaviour and environmental conditions.

scholarly journals Energy expenditure of free-living reindeer estimated by the doubly labelled water method

Rangifer ◽  
2000 ◽  
Vol 20 (2-3) ◽  
pp. 211 ◽  
Author(s):  
Geir Gotaas ◽  
Eric Milne ◽  
Paul Haggarty ◽  
Nicholas J.C. Tyler
Keyword(s):  
Energy Expenditure ◽  
Rangifer Tarandus ◽  
Water Flux ◽  
Co2 Production ◽  
Wild Ungulates ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Svalbard Reindeer ◽  
Mountain Pasture ◽  
The Mean

The doubly labelled water (DLW) method was used to measure total energy expenditure (TEE) in three male reindeer (Rangifer tarandus tarandus) aged 22 months in winter (February) while the animals were living unrestricted at natural mountain pasture in northern Norway (69&deg;20'N). The concentrations of 2H and l8O were measured in water extracted from samples of faeces collecred from the animals 0.4 and 11.2 days after injection of the isotopes. Calculated rates of water flux and CO2-production were adjusted to compensate for estimated losses of 2H in faecal solids and in methane produced by microbial fermentation of forage in the rumen. The mean specific TEE in the three animals was 3.057 W.kg-1 (range 2.436 - 3.728 W.kg1). This value is 64% higher than TEE measured by the DLW method in four captive, non-pregnant adult female reindeer in winter and probably mainly reflects higher levels of locomotor activity in the free-living animals. Previous estimates of TEE in free-living Rangifer in winter based on factorial models range from 3.038 W.kg-1 in female woodland caribou (R. t. caribou) to 1.813 W.kg-1 in female Svalbard reindeer (R. t. platyrhynchus). Thus, it seems that existing factorial models are unlikely to overestimate TEE in reindeer/caribou: they may, instead, be unduly conservative. While the present study serves as a general validation of the factorial approach, we suggest that the route to progress in the understanding of field energetics in wild ungulates is via application of the DLW method.

scholarly journals Review of Prediction Models to Estimate Activity-Related Energy Expenditure in Children and Adolescents

2010 ◽  
Vol 2010 ◽  
pp. 1-14 ◽  
Author(s):  
Suzanne M. de Graauw ◽  
Janke F. de Groot ◽  
Marco van Brussel ◽  
Marjolein F. Streur ◽  
Tim Takken
Keyword(s):  
Heart Rate ◽  
Energy Expenditure ◽  
Prediction Model ◽  
Children And Adolescents ◽  
Prediction Models ◽  
Accurate Estimate ◽  
Healthy Children ◽  
Triaxial Accelerometer ◽  
Free Living ◽  
Doubly Labelled Water

Purpose. To critically review the validity of accelerometry-based prediction models to estimate activity energy expenditure (AEE) in children and adolescents.Methods. The CINAHL, EMBASE, PsycINFO, and PubMed/MEDLINE databases were searched. Inclusion criteria were development or validation of an accelerometer-based prediction model for the estimation of AEE in healthy children or adolescents (6–18 years), criterion measure: indirect calorimetry, or doubly labelled water, and language: Dutch, English or German.Results. Nine studies were included. Median methodological quality was5.5±2.0 IR (out of a maximum 10 points). Prediction models combining heart rate and counts explained 86–91% of the variance in measured AEE. A prediction model based on a triaxial accelerometer explained 90%. Models derived during free-living explained up to 45%.Conclusions. Accelerometry-based prediction models may provide an accurate estimate of AEE in children on a group level. Best results are retrieved when the model combines accelerometer counts with heart rate or when a triaxial accelerometer is used. Future development of AEE prediction models applicable to free-living scenarios is needed.

scholarly journals Description and validation of the ActiReg®: a novel instrument to measure physical activity and energy expenditure

2004 ◽  
Vol 92 (6) ◽  
pp. 1001-1008 ◽  
Author(s):  
Bo-Egil Hustvedt ◽  
Alf Christophersen ◽  
Lene R. Johnsen ◽  
Heidi Tomten ◽  
Geraldine McNeill ◽  
...  
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Body Position ◽  
Energy Costs ◽  
Motion Sensors ◽  
Storage Unit ◽  
Doubly Labelled Water ◽  
The Right ◽  
Different Levels ◽  
Objective Recording

The ActiReg® (PreMed AS, Oslo, Norway) system is unique in using combined recordings of body position and motion alone or combined with heart rate (HR) to calculate energy expenditure (EE) and express physical activity (PA). The ActiReg® has two pairs of position and motion sensors connected by cables to a battery-operated storage unit fixed to a waist belt. Each pair of sensors was attached by medical tape to the chest and to the front of the right thigh respectively. The collected data were transferred to a personal computer and processed by a dedicated program ActiCalc®. Calculation models for EE with and without HR are presented. The models were based on literature values for the energy costs of different activities and therefore require no calibration experiments. The ActiReg® system was validated against doubly labelled water (DLW) and indirect calorimetry. The DLW validation demonstrated that neither EE calculated from ActiReg® data alone (EEAR) nor from combined ActiReg® and HR data (EEAR–HR) were statistically different from DLW results. The EEAR procedure causes some underestimation of EE >11 MJ corresponding to a PA level >2·0. This underestimation is reduced by the EEAR–HR procedure. The objective recording of the time spent in different body positions and at different levels of PA may be useful in studies of PA in different groups and in studies of whether recommendations for PA are being met. The comparative ease of data collection and calculation should make ActiReg® a useful instrument to measure habitual PA level and EE.

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