Basal Metabolic Rate (BMR) - Definition, Functions, Factors

Definition of Basal Metabolic Rate (BMR)

Basal Metabolic Rate (BMR) refers to the amount of energy, measured in calories, that your body requires to perform its most basic, life-sustaining functions at rest.
These functions include:
- Breathing
- Circulation
- Cell production
- Nutrient processing
- Protein synthesis
- Ion transport

Basal Metabolic Rate (BMR) represents the minimum calorie requirement needed to keep your body functioning at rest, including:
- Maintaining body temperature
- Repairing cells
- Carrying out other essential metabolic processes

Body Size and Composition:
- Individuals with more muscle mass have a higher BMR because muscle tissue burns more calories than fat tissue, even at rest.
Sex:
- Males generally have a higher BMR compared to females due to a higher proportion of muscle mass.
Age:
- BMR decreases with age due to a decrease in muscle mass and other physiological changes.
Genetics:
- Genetic factors can influence an individual’s BMR, leading to variations in metabolic rates.
Hormonal and Health Status:
- Thyroid hormones play a significant role in regulating BMR.
- Conditions such as hyperthyroidism (increased BMR) or hypothyroidism (decreased BMR) affect metabolic rates.
- Other health conditions and hormonal imbalances also influence BMR.

Energy Balance: Calculating BMR is essential for understanding and managing energy balance.
Caloric Needs: It helps estimate the total number of calories needed to maintain current weight.
Weight Management: Knowing your BMR aids in setting accurate daily calorie intake targets for weight loss, gain, or maintenance.

The Harris-Benedict Equation and the Mifflin-St Jeor Equation are widely used to estimate BMR.
These formulas take into account factors such as age, sex, weight, and height.

These formulas provide estimates, and actual calorie needs may vary based on additional factors like physical activity levels and overall health status.