Variations and determinants of energy expenditure as measured by whole-body indirect calorimetry during puberty and adolescence

Bitar, Abdelali; Fellmann, Nicole; Vernet, Jean; Coudert, J; Vermorel, M.

doi:10.1093/ajcn/69.6.1209

Cited by 61 publications

(60 citation statements)

References 21 publications

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“…Their usual activity was estimated by interview. Anatomical measurements and sexual maturity were determined according to the protocols described previously for the same subjects (Bitar et al, 1999). Body composition was assessed by using both the skinfold-thickness method and bioimpedance analysis.…”

Section: Subjectsmentioning

confidence: 99%

“…Peak oxygen uptake (peak VO 2 ) was measured by a direct method (respiratory gas exchange) during exercises on a cycloergometer. The subjects performed several successive 3 min steps against increasing braking forces until exhaustion (Bitar et al, 1999).…”

Section: Subjectsmentioning

confidence: 99%

Section: Subjectsmentioning

confidence: 99%

“…EE was calculated from oxygen consumption, carbon dioxide production, and 24 h urinary nitrogen (N u ) excretion by using Brouwer's equation (1965): EE (kJ) ¼ 16:18 O 2 ðlÞ þ 5:02 CO 2 ðlÞ À 6:00 N u ðgÞ over 5 min periods during exercise and 15 min periods for the rest of the day (Bitar et al, 1999). HR was recorded continuously by telemetry during the same period according to a standardized activity program including sleep, basal metabolic rate (BMR), meals, seated activities (schoolwork, reading, games and watching television), four 15 min periods of exercise on a cycle ergometer, and the recovery periods (Bitar et al, 1999). In addition, EE of subjects was determined during laboratory tests by open-circuit calorimetry using a face mask and an automated on-line system (CPX ID; Medical Graphics, St Paul, MN USA) for usual activities which could not Individual general relationships were computed between data for EE and HR recorded both in the whole-body calorimeters during 24 h and during the laboratory tests: two linear relationships with determination of the flex-HR value, an exponential relationship for HRs below the flex-HR value and a linear relationship above the flex-HR value, and polynomial relationships (Bitar et al, 1996).…”

Section: Subjectsmentioning

confidence: 99%

“…The variations and determinants of EE of 62 12 -16-y-old boys and girls have been studied in our laboratories with a standardized activity program using whole-body indirect calorimeters (Bitar et al, 1999). The objectives of the present cross-sectional study were to determine: (1) DEE and its main components in the same adolescents in free living conditions; (2) day-to-day variations in DEE and activity pattern; and (3) time devoted to, EE and energy costs of the various activities.…”

Section: Introductionmentioning

confidence: 99%

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Daily energy expenditure, activity patterns, and energy costs of the various activities in French 12–16-y-old adolescents in free living conditions

et al. 2002

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Background: Changes in lifestyle and increases in sedentary activities during recent decades have been shown to contribute to the prevalence of overweight in adolescents. Objectives: To determine the inter-individual variability and the day-to-day variations in daily energy expenditure (DEE) and activity pattern, and the energy costs and EE of the various activities of adolescents in free-living conditions. Design: Sixty adolescents (four groups of 14 -16 boys or girls aged 12 -16 y) participated in this cross-sectional study during spring or autumn. Activity patterns and EE were determined during five consecutive days, using both a diary and the heart rate recording method validated by whole-body calorimetry and laboratory tests. Results: Mean DEE increased significantly with age in boys, but not in girls. However, the physical activity level did not vary significantly with sex and age. Mean DEE was significantly higher in spring than in autumn in the 12.6-y-old subjects. It was also 21% higher during the free days than during the schooldays in the active subjects, but 7% lower in the sedentary subjects. The energy cost of 22 activities was determined. Time and energy devoted to moderate and sport activities exhibited great interindividual variability. They were lower in girls than in boys and decreased with age. The increase in EE resulting from moderate and sport activities instead of sedentary activities ranged from 0.2 to 2.7 MJ=day over the week. Conclusion: The great variability in DEE of adolescents resulted mainly from differences in the nature, duration and intensity of physical activities during the free days.

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Section: Subjectsmentioning

confidence: 99%

Section: Subjectsmentioning

confidence: 99%

Section: Subjectsmentioning

confidence: 99%

Section: Subjectsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Daily energy expenditure, activity patterns, and energy costs of the various activities in French 12–16-y-old adolescents in free living conditions

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Morphological and functional implications of sexual dimorphism in the human skeletal thorax

García‐Martínez

Torres-Tamayo

Torres-Sánchez

et al. 2016

American J Phys Anthropol

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Number of tables: 2Abbreviated title: 3D morphometrics of human rib cage.Key words: rib cage; geometric morphometrics; sex differences. This is the peer reviewed version of the following article: American Journal of Physical Anthropology 161(3): 467-477 (2016), which has been published in final form at http://dx.doi.org/10.1002/ajpa.23051. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. *Corresponding author:2 Title: Morphological and functional implications of sexual dimorphism in the human skeletal thorax. ABSTRACT Objectives:The human respiratory apparatus is characterized by sexual dimorphism, the cranial airways of males being larger (both absolutely and relatively) than those of females. These differences have been linked to sex-specific differences in body composition, bioenergetics and respiratory function. However, whether morpho-functional variation in the thorax is also related to these features is less clear. We apply 3D geometric morphometrics to study these issues and their implications for respiratory function. Material and methods:402 landmarks and semilandmarks were measured in CT-reconstructions of rib cages from adult healthy subjects (N male =18; N female =24) in maximal inspiration (MI) and maximal expiration (ME). After Procrustes registration, size and shape data were analyzed by mean comparisons and regression analysis. Respiratory function was quantified through functional size, which is defined as the difference of rib cage size between MI and ME.Results: Males showed significantly larger thorax size (p<0.01) and functional size (p<0.05) than females. In addition, the 3D-shape differed significantly between sexes (p<0.01). Male rib cages were wider (particularly caudally) and shorter, with more horizontally oriented ribs when compared to females. While thorax widening and rib orientation were unrelated to allometry, thorax shortening showed a slight allometric signal. Conclusions:Our findings are in line with previous research on sexual dimorphism of the respiratory system. However, we add that thorax shortening observed previously in males is the only feature caused by allometry. The more horizontally oriented ribs and the wider thorax of males may indicate a greater diaphragmatic contribution to rib cage kinematics than in females, and differences in functional size fit with the need for greater oxygen intake in males.3

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Three‐dimensional analysis of sexual dimorphism in ribcage kinematics of modern humans

García‐Martínez

Bastir

Torres-Tamayo

et al. 2019

American J Phys Anthropol

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Objectives: Sexual dimorphism is an important biological factor underlying morphological variation in the human skeleton. Previous research found sex-related differences in the static ribcage, with males having more horizontally oriented ribs and a wider lower ribcage than females. Furthermore, a recent study found sex-related differences in the kinematics of the human lungs, with cranio-caudal movements of the caudal part of the lungs accounting for most of the differences between sexes. However, these movements cannot be quantified in the skeletal ribcage, so we do not know if the differences observed in the lungs are also reflected in sex differences in the motion of the skeletal thorax. Materials and methods:To address this issue, we quantified the morphological variation of 42 contemporary human ribcages (sex-balanced) in both maximal inspiration and expiration using 526 landmarks and semilandmarks. Thoracic centroid size differences between sexes were assessed using a t test, and shape differences were assessed using Procrustes shape coordinates, through mean comparisons and dummy regressions of shape on kinematic status. A principal components analysis was used to explore the full range of morphological variation.Results: Our results show significant size differences between males and females both in inspiration and expiration (p < .01) as well as significant shape differences, with males deforming more than females during inspiration, especially in the mediolateral dimension of the lower ribcage. Finally, dummy regressions of shape on kinematic status showed a small but statistically significant difference in vectors of breathing kinematics between males and females (14.78 ; p < .01).Discussion: We support that sex-related differences in skeletal ribcage kinematics are discernible, even when soft tissues are not analyzed. We hypothesize that this differential breathing pattern is primarily a result of more pronounced diaphragmatic breathing in males, which might relate to differences in body composition, metabolism, and ultimately greater oxygen demand in males compared to females. Future research should further explore the links between ribcage morphological variation and basal metabolic rate.

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Variations and determinants of energy expenditure as measured by whole-body indirect calorimetry during puberty and adolescence

Abstract: The DEE of adolescents measured under standardized conditions varied with sex, body composition, and season, but not with stage of puberty. These variables could be predicted accurately from fat-free mass, sex, and season.

Cited by 61 publications

References 21 publications

Daily energy expenditure, activity patterns, and energy costs of the various activities in French 12–16-y-old adolescents in free living conditions

Daily energy expenditure, activity patterns, and energy costs of the various activities in French 12–16-y-old adolescents in free living conditions

Morphological and functional implications of sexual dimorphism in the human skeletal thorax

Three‐dimensional analysis of sexual dimorphism in ribcage kinematics of modern humans

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