Definition
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
Functions
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
1. 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.
2. Sex
Generally, males have a higher BMR compared to females because they tend to have more muscle mass.
3. Age
BMR tends to decrease with age due to a decrease in muscle mass and other physiological changes.
4. Genetics
Genetic factors can also play a role in determining an individual's BMR.
5. Hormonal and Health Status
Thyroid hormones significantly affect BMR.
Conditions such as hyperthyroidism or hypothyroidism can lead to an increase or decrease in BMR, respectively.
Other health conditions and hormonal balances also influence BMR.
Importance of 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.
BMR Calculation
Common Formulas
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.
Considerations
These formulas provide estimates, and actual calorie needs may vary based on additional factors like physical activity levels and overall health status.