scholarly journals Constraint and trade-offs regulate energy expenditure during childhood

2019 ◽  
Vol 5 (12) ◽  
pp. eaax1065 ◽  
Author(s):  
Samuel S. Urlacher ◽  
J. Josh Snodgrass ◽  
Lara R. Dugas ◽  
Lawrence S. Sugiyama ◽  
Melissa A. Liebert ◽  
...  

Children’s metabolic energy expenditure is central to evolutionary and epidemiological frameworks for understanding variation in human phenotype and health. Nonetheless, the impact of a physically active lifestyle and heavy burden of infectious disease on child metabolism remains unclear. Using energetic, activity, and biomarker measures, we show that Shuar forager-horticulturalist children of Amazonian Ecuador are ~25% more physically active and, in association with immune activity, have ~20% greater resting energy expenditure than children from industrial populations. Despite these differences, Shuar children’s total daily energy expenditure, measured using doubly labeled water, is indistinguishable from industrialized counterparts. Trade-offs in energy allocation between competing physiological tasks, within a constrained energy budget, appear to shape childhood phenotypic variation (e.g., patterns of growth). These trade-offs may contribute to the lifetime obesity and metabolic health disparities that emerge during rapid economic development.

1994 ◽  
Vol 76 (4) ◽  
pp. 1818-1822 ◽  
Author(s):  
R. W. Hoyt ◽  
J. J. Knapik ◽  
J. F. Lanza ◽  
B. H. Jones ◽  
J. S. Staab

The rate of metabolic energy expenditure during locomotion (Mloco) is proportional to body weight (Wb) divided by the time during each stride that a single foot contacts the ground (tc) (Nature Lond. 346: 265–267, 1990). Using this knowledge, we developed an electronic foot contact monitor. Our objective was to derive and cross-validate an equation for estimation Mloco from Wb/tc. Twelve males were tested [age = 19.4 +/- 1.4 (SD) yr, Wb = 78.4 +/- 8.0 kg] during horizontal treadmill walking (0.89, 1.34, and 1.79 m/s) and running (2.46, 2.91, and 3.35 m/s). Measured Mloco was defined as the total rate of energy expenditure, measured by indirect calorimetry, minus the estimated rate of resting energy expenditure. The equation to estimate Mloco was derived in six randomly selected subjects: Mloco = 3.702.(Wb/tc) - 149.6 (r2 = 0.93). Cross-validation in the remaining six subjects showed that estimated and measured Mloco were highly correlated (r2 = 0.97). The average individual error between estimated and measured Mloco was 0% (range -22 to 29%). In conclusion, Mloco can be accurately estimated from Wb and measurements of tc made by an ambulatory foot contact monitor.


Author(s):  
Kaitlin L Ballenger ◽  
Nicol Tugarinov ◽  
Sara K Talvacchio ◽  
Marianne M Knue ◽  
An N Dang Do ◽  
...  

Abstract Context Mutations in type I collagen or collagen-related proteins cause Osteogenesis Imperfecta (OI). Energy expenditure and body composition in OI could reflect reduced mobility, or intrinsic defects in osteoblast differentiation increasing adipocyte development. Objective Compare adiposity and resting energy expenditure (REE) in OI and healthy controls (HC), for OI genotype- and Type-associated differences. Design/Setting/Participants We studied 90 participants, 30 with OI (13 COL1A1 Gly, 6 COL1A2 Gly, 3 COL1A1 non-Gly, 2 COL1A2 non-Gly, 6 non-COL; 8 Type III, 16 Type IV, 4 Type VI, 1 Type VII, 1 Type XIV) and 60 HC with sociodemographic characteristics/BMI/BMIz similar to the OI group. Participants underwent dual-energy X-ray absorptiometry to determine lean mass and fat mass percentage (FM%) and REE. FM% and REE were compared, adjusting for covariates to examine the relationship of OI genotypes and phenotypic Types. Results FM% did not differ significantly in all patients with OI versus HC (OI: 36.6±1.9%, HC: 32.7±1.2%, p =0.088). FM% was, however, greater than HC for those with non-COL variants (p=0.018). FM% did not differ from HC among OI Types (p’s>0.05). Overall, covariate-adjusted REE did not differ significantly between OI and HC (OI: 1376.5±44.7 kcal/d, healthy controls: 1377.0±96 kcal/d p=0.345). However, those with non-COL variants (p=0.034) and Type VI OI (p=0.04) had significantly lower REE than HC. Conclusions Overall, patients with OI did not significantly differ in either extra-marrow adiposity or REE from BMI-similar HC. However, reduced REE among those with non-COL variants may contribute to greater adiposity.


2006 ◽  
Vol 22 (02) ◽  
pp. 66-71
Author(s):  
Yasuhisa Okumoto

This report focuses on welding work for the assembly of large steel structures as an example of physical jobs. Task simulations using a digital human model, including metabolic energy expenditure analysis, have been carried out using the biomechanical approach for typical welding postures. Moreover, necessary rest time to recover from fatigue has been studied, and the optimal work cycle in a day was examined. As a result, it can be concluded that the flat position for welding, the most widely applied posture, requires the greatest energy expenditure, whereas the overhead position is requires the least. Furthermore, it is concluded that the rule of taking short breaks and often is preferable from the viewpoint of recovery from fatigue, especially for work where the consumption of energy is large. Finally, an optimal work cycle is proposed.


2019 ◽  
Vol 184 (7-8) ◽  
pp. e281-e287
Author(s):  
Caitlin E Mahon ◽  
Benjamin J Darter ◽  
Christopher L Dearth ◽  
Brad D Hendershot

Abstract Introduction Temporal-spatial symmetry allows for optimal metabolic economy in unimpaired human gait. The gait of individuals with unilateral transfemoral amputation is characterized by temporal-spatial asymmetries and greater metabolic energy expenditure. The objective of this study was to determine whether temporal-spatial asymmetries account for greater metabolic energy expenditure in individuals with unilateral transfemoral amputation. Materials and Methods The relationship between temporal-spatial gait asymmetry and metabolic economy (metabolic power normalized by walking speed) was retrospectively examined in eighteen individuals with transfemoral amputation walking at a self-selected velocity overground. Pearson’s product-moment correlations were used to assess the relationship between: (1) step time symmetry and metabolic economy and (2) step length symmetry and metabolic economy. The retrospective analysis of this data was approved by the Walter Reed National Military Medical Center Institutional Review Board and all individuals provided written consent. Additional insights on this relationship are presented through a case series describing the temporal-spatial and metabolic responses of two individuals with transfemoral amputation who completed a split-belt treadmill walking test. Results For the cohort of individuals, there was no significant relationship between metabolic economy and either step time asymmetry or step length asymmetry. However, the case series showed a positive relationship between step length asymmetry and metabolic power as participants adapted to split-belt treadmill walking. Conclusion There is mixed evidence for the relationship between temporal-spatial asymmetries and metabolic energy expenditure. This preliminary study may suggest optimal metabolic energy expenditure in individuals with transfemoral amputation occurs at an individualized level of symmetry and resultant deviations incur a metabolic penalty. The results of this study support the idea that addressing only temporal-spatial gait asymmetries in individuals with transfemoral amputation through rehabilitation may not improve metabolic economy. Nevertheless, future prospective research is necessary to confirm these results and implications for clinical practice.


2013 ◽  
Vol 38 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Benjamin J Darter ◽  
Jason M Wilken

Background:Technological advances in prosthetic design include the use of microprocessors that adapt device performance based on user motion. The Proprio ankle unit prepositions the foot to adjust for walking on slopes and increases foot clearance during swing to minimize gait deviations.Study design:Comparative analysis.Objectives:To investigate the effect of a prosthesis with adaptive ankle motion on physiological gait performance during slope walking.Methods:Six persons with a unilateral transtibial amputation completed treadmill walking tests at three slopes (−5°, 0°, and 5°). The participants were tested wearing a customary device, active Proprio (Pon), and an identical inactivated Proprio (Poff).Results:Metabolic energy expenditure, energy cost for walking, and rating of walking difficulty were not statistically different between the Pon and Poff for all tested slopes. However, for slope descent, energy expenditure and energy cost for walking improved significantly by an average of 10%–14% for both the Pon and Poff compared to the customary limb. Rating of walking difficulty also showed an improvement with slope descent for both the Pon and Poff compared to the customary device. An improvement with slope ascent was found for Pon compared to the customary limb only.Conclusions:Adaptive ankle motion provided no meaningful physiological benefit during slope walking. The Proprio was, however, less demanding than the customary device for slope descent. Differences in the mechanical properties of the prosthetic feet likely contributed to the changes.Clinical relevanceWhile the adaptive ankle motion did not affect metabolic energy expenditure or energy cost for walking, the results suggest close attention should be paid to the mechanical properties of the foot component. Assessment of gait on nonlevel surfaces is recommended to better understand the implications of different prosthetic design features.


1990 ◽  
Vol 64 (2) ◽  
pp. 413-425 ◽  
Author(s):  
Jan A. Weststrate ◽  
Ingrid Wunnink ◽  
Paul Deurenberg ◽  
Joseph G. A. J. Hautvast

The impact of alcohol (ethanol) on resting energy expenditure of male non-obese volunteers was determined in two studies. In the first study the thermic effect of alcohol on resting metabolic rate (RMR) was assessed in ten male non-obese volunteers. In the second study the impact of alcohol on diet-induced thermogenesis (DIT) was determined in twelve male non-obese volunteers. Energy expenditure was measured with a ventilated-hood system. RMR was measured for 60 min with the subjects in a fasting state. In the first study subjects received in random order 20 g alcohol in concentrations of 75, 180 and 300 ml/I water respectively. After measurement of the RMR the thermic effect of alcohol was measured for 90 min. In the second study volunteers received in random order and in duplicate either a meal of food (2 MJ) plus an alcoholic aperitif (20 g alcohol in a 180 ml/1 solution) or an isoenergetic meal of food alone (2.55 MJ) plus a placebo aperitif containing no alcohol. DIT was measured for 240 min. Alcohol induced a significant thermic effect, which varied between 0.22 and 0.30 kJ/min. No systematic difference in DIT was observed among the different concentrations. DIT was not significantly affected by the ingestion of alcohol. Total DIT was 219 (SE 14) kJ for the alcohol treatment and 185 (SE 20) kJ for the control treatment. The results do not support the suggestion that alcohol is less efficiently used as an energy source in comparison with, for example, fats and carbohydrates.


2000 ◽  
Vol 85 (4) ◽  
pp. 1550-1556 ◽  
Author(s):  
Eric Doucet ◽  
Sylvie St. Pierre ◽  
Natalie Alméras ◽  
Pascale Mauriège ◽  
Denis Richard ◽  
...  

The aim of the present study was to determine the impact of weight loss and its related metabolic and hormonal changes on resting energy expenditure (REE) and substrate oxidation. Forty subjects (16 men and 24 women) took part in a 15-week weight loss program that consisted of drug therapy (fenfluramine, 60 mg/day) or placebo coupled to an energy restriction (−700 Cal/day). Subjects were asked to come to the laboratory after an overnight fast for an indirect calorimetry measurement before and after weight loss. Fasting blood samples were also drawn and were analyzed for plasma glucose, insulin, leptin, and free fatty acid determinations. This program reduced body weight by 11% and 9% (P < 0.01) in men and women, respectively. Fat mass (FM) and fat-free mass (FFM) were also significantly reduced in both sexes. A significant decrease in REE (13%; P < 0.01) and fat oxidation (11%; P = 0.08) was observed in men in response to this program, whereas no significant differences were noted for these variables in women. In men, positive correlations were found between changes in FFM and energy-related variables, whereas the best predictor of changes in REE and substrate oxidation was the change in FM in women. The most important finding of this study is that in men, the association between changes in fasting plasma leptin and changes in REE (r = 0.50; P < 0.01) and fat oxidation (r = 0.63; P < 0.01) persist after correction for changes in body composition. These results suggest that a comparable weight loss is accompanied by a greater decrease in REE and substrate oxidation in men than in women, and that these changes are better explained by changes in leptinemia in men and by changes in FM in women.


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