Effects of supplemental fish oil on resting metabolic rate, body composition, and salivary cortisol in healthy adults

Objetivo: Analisar a composição corporal e taxa metabólica de repouso (TMR) de adolescentes com obesidade. Metodologia: Foram avaliados 58 adolescentes, entre 12 e 16 anos (13,7±1,2 anos), com obesidade. A composição corporal foi mensurada por meio da Absortiometria de Raios-x de Dupla Energia (DEXA). A taxa metabólica de repouso e a oxidação de glicose e lipídeos foram determinadas pela medida do oxigênio consumido e pela produção de dióxido de carbono. Foi utilizado teste t de Student para variáveis independentes, análise de regressão linear múltipla e correlação de Pearson, com significância de p<5%. Resultados: Foram observadas diferenças na porcentagem de gordura corporal (p=0,01), porcentagem de massa corporal magra (MCM) (p=0,01), porcentagem de gordura do tronco (p=0,01), massa magra membro inferior (p=0,01) e taxa metabólica de repouso (p=0,04) entre os sexos masculino e feminino. No sexo masculino a MCM foi a melhor preditora de TMR (p=0,01). Houve correlação positiva entre TMR e MCM, assim como observada associação entre a oxidação lipídica e MCM. Conclusão: A composição corporal total e por segmento corporal influenciam a taxa metabólica de repouso e a oxida- ção de substratos. Além disso, a MCM pode ser considerada um fator de aumento do gasto energético de repouso de adolescentes com obesidade.

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Effect of age on body composition and resting metabolic rate

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1990.259.2.e233 ◽

1990 ◽

Vol 259 (2) ◽

pp. E233-E238 ◽

Cited By ~ 20

Author(s):

N. K. Fukagawa ◽

L. G. Bandini ◽

J. B. Young

Keyword(s):

Body Composition ◽

Metabolic Rate ◽

Isotope Dilution ◽

Resting Metabolic Rate ◽

Bioelectrical Impedance ◽

Impedance Analysis ◽

Open Circuit ◽

Fat Free Mass ◽

The Difference ◽

Old Men

The relationship between fat-free mass (FFM) and resting metabolic rate (RMR) was compared in young men (n = 24; age 18-33 yr), old men (n = 24; 69-89 yr), and old women (n = 20; 67-75 yr). Body composition was assessed using anthropometry, bioelectrical impedance analysis (BIA), and isotope dilution with 18O-labeled water. RMR was measured at least twice using an open-circuit indirect calorimetry system with a ventilated hood. The results indicate that the different methods for assessing body composition vary substantially and should not be used interchangeably. Anthropometry was not adequate to assess group differences in body fatness, although skinfold measures may be appropriate for within-group comparisons. BIA correlated well with the isotope-dilution technique and may be a useful measure of FFM. Finally, RMR was lower in the old men than the young (1.04 +/- 0.02 vs. 1.24 +/- 0.03 kcal/min, P less than 0.001) and remained lower even when adjusted for FFM estimated by isotope dilution (P less than 0.001). RMR in the women was also lower (0.84 +/- 0.02 kcal/min), but in contrast to the difference between young and old men, RMR adjusted for FFM did not differ (P = 0.16) between old men and women. Therefore, it is clear that differences in FFM cannot fully account for the lower RMR in the old, suggesting that aging is associated with an alteration in tissue energy metabolism.

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Two Novel Models Evaluating the Determinants of Resting Metabolic Rate in Indian Children

10.21203/rs.3.rs-196719/v1 ◽

2021 ◽

Author(s):

Sandra Aravind Areekal ◽

Anuradha Khadilkar ◽

Veena Ekbote ◽

Neha Kajale ◽

Arun S. Kinare ◽

...

Keyword(s):

Body Composition ◽

Metabolic Rate ◽

Resting Metabolic Rate ◽

Childhood Development ◽

Relative Mass ◽

Kidney Volume ◽

Indian Children ◽

Cross Sectional ◽

Multi Centre Study ◽

The Mean

Abstract Resting metabolic rate (RMR) quantifies the minimal energy required to sustain vital body functions and is a crucial component of childhood development. While inter-individual variations in RMR have been studied for over a century they are poorly understood. Wang (Am. J. Hum., 2012) has modelled mean RMR per unit body mass (RMR/BM) in children grouped into age classes one year apart; this model is able to explain the variation in RMR/BM very accurately in a reference Caucasian dataset based on the relative masses of four major organs (liver, kidney, brain, heart) and the residual mass. However, it is not clear if it applies to other ethnicities, especially when the variation in the RMR is observed to be large in a population. Here we address the extent to which such a model can be adapted to explain RMR/BM in Indian children. Here we present two novel phenomenological models that describe the mean RMR/BM stratified by age in Indian children and adolescents, using data from the Multi-Centre Study (MCS) and RMR-USG. MCS is a cross-sectional dataset on 495 (235 girls) children aged 9 to 19 years with anthropometric, body composition and RMR measurements. RMR-USG consists of anthropometric data, RMR, and liver and kidney volume measured through ultrasonography in nine girls and nine boys aged 6 to 8 years. The mean RMR/BM in Indian children is observed to be significantly lower compared to their Caucasian counterparts, except in boys in the age groups 9 to 11 years and 12 to 13 years. The first is a modified Wang model in which the relative masses of four major organs are assumed to be uniformly lowered for Indian children. Theoretical predictions of size are not uniformly borne out in a pilot validation study, however, the relative mass of the kidney is indeed found to be significantly lower. We then present another version of the Wang model to demonstrate that changes in body composition alone can also explain the Indian data. Either model can be thus used phenomenologically to estimate mean RMR/BM by age in Indian children; however, understanding the mechanistic basis of variation in RMR/BM remains an open problem.

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