The scaling of human basal and resting metabolic rates
Publication Name
European Journal of Applied Physiology
Abstract
Purpose: In tachymetabolic species, metabolic rate increases disproportionately with body mass, and that inter-specific relationship is typically modelled allometrically. However, intra-specific analyses are less common, particularly for healthy humans, so the possibility that human metabolism would also scale allometrically was investigated. Methods: Basal metabolic rate was determined (respirometry) for 68 males (18–40 years; 56.0–117.1 kg), recruited across five body-mass classes. Data were collected during supine, normothermic rest from well-rested, well-hydrated and post-absorptive participants. Linear and allometric regressions were applied, and three scaling methods were assessed. Data from an historical database were also analysed (2.7–108.9 kg, 4811 males; 2.0–96.4 kg, 2364 females). Results: Both linear and allometric functions satisfied the statistical requirements, but not the biological pre-requisite of an origin intercept. Mass-independent basal metabolic data beyond the experimental mass range were not achieved using linear regression, which yielded biologically impossible predictions as body mass approached zero. Conversely, allometric regression provided a biologically valid, powerful and statistically significant model: metabolic rate = 0.739 * body mass (P < 0.05). Allometric analysis of the historical male data yielded an equivalent, and similarly powerful model: metabolic rate = 0.873 * body mass (P < 0.05). Conclusion: It was established that basal and resting metabolic rates scale allometrically with body mass in humans from 10–117 kg, with an exponent of 0.50–0.55. It was also demonstrated that ratiometric scaling yielded invalid metabolic predictions, even within the relatively narrow experimental mass range. Those outcomes have significant physiological implications, with applications to exercising states, modelling, nutrition and metabolism-dependent pharmacological prescriptions. 0.547 0.497
Open Access Status
This publication is not available as open access
Volume
121
Issue
1
First Page
193
Last Page
208
Funding Number
2019H1D3A2A01061171
Funding Sponsor
National Research Foundation of Korea