What Determines Your Basal Metabolic Rate?
13 days ago
- #health
- #body composition
- #metabolism
- Basal metabolic rate (BMR) is the energy your body burns at rest to maintain basic functions.
- BMR is influenced by body composition and the metabolic rates of different tissues.
- Muscle burns 13 Calories/kg, while fat burns 4.5 Calories/kg, making muscle gain and fat loss less impactful on BMR than expected.
- High-metabolic-rate organs (heart, kidneys, brain, liver) account for over 50% of BMR despite being less than 5% of body mass.
- Granular body composition, including organ size, significantly affects BMR, with slight variations causing large differences.
- Standard BMR equations can under- or overestimate by 300-400 Calories due to inaccuracies in predicting high-metabolic-rate tissue mass.
- MRI-based assessments improve BMR accuracy by better estimating organ masses.
- BMR per unit of fat-free mass decreases as fat-free mass increases, due to a higher proportion of low-metabolic-rate tissues.
- Future articles will explore how age, sex, and athleticism affect BMR, and how to refine BMR prediction equations.