Resting energy expenditure (REE), sometimes called Resting Metabolic Rate (RMR), is the total amount of energy your body uses to maintain its most basic functions while completely at rest. It is not to be confused with Basal Metabolic Rate (BMR), which is a more restrictive measurement taken under very specific, controlled conditions. For most practical purposes, REE is the more commonly used and useful metric. It represents the largest portion of your total daily energy expenditure (TDEE), often accounting for 60-75% of the calories you burn daily. This article explores the specifics of REE for women, how it is calculated, and what factors influence it.
The Calculation of REE for Women
Unlike BMR, which requires a clinical setting for a precise measurement through indirect calorimetry, REE can be accurately estimated using predictive equations. The Mifflin-St Jeor equation is generally considered more accurate for a modern population, including overweight and obese individuals, and uses weight, height, and age for its calculation. The revised Harris-Benedict equation is another method, developed earlier and revised, but is considered slightly less accurate for some populations. It also uses weight, height, and age. You can find these equations and learn more about calculating your RMR on {Link: NASM website https://www.nasm.org/resource-center/blog/resting-metabolic-rate-how-to-calculate-and-improve-yours}.
Factors Influencing Resting Energy Expenditure
Many elements beyond simple demographics like age and size affect a woman's REE. Key influencing factors include body composition (particularly lean body mass), age, hormonal status (including menstrual cycle fluctuations), and genetics. A woman's RMR can decrease by approximately 2% per decade after her peak growth years. Regular exercise, especially strength training, can increase lean body mass and boost REE over time. Consistently eating very low-calorie diets can suppress RMR by as much as 20%.
Comparison of REE Estimation Formulas
| Feature | Mifflin-St Jeor Equation | Revised Harris-Benedict Equation |
|---|---|---|
| Development | Published in the 1990s | Published in 1919, revised in 1984 |
| Accuracy | Generally considered more accurate for modern populations, including overweight and obese individuals. | Widely used but can be less accurate than Mifflin-St Jeor. |
| Gender Specificity | Has a gender-specific calculation. | Also uses a gender-specific formula. |
| Variables Used | Weight (kg), Height (cm), Age (years) | Weight (kg), Height (cm), Age (years) |
| Recommended For | More reliable for a general population seeking an estimate. | Useful for historical context, but less precise than Mifflin-St Jeor. |
The Role of REE in Weight Management
Understanding REE is essential for effective weight management. It's the baseline for overall energy expenditure, which also includes physical activity and the thermic effect of food. Creating a caloric deficit based on an accurate REE is necessary for weight loss and helps avoid metabolic slowdown from aggressive restriction.
How to Improve Your REE
Here are actionable steps to positively influence your REE:
- Build Lean Body Mass: Strength training is effective for boosting REE by increasing muscle mass.
- Ensure Adequate Caloric Intake: Avoid severe calorie restriction, which can lower your metabolic rate.
- Stay Hydrated: Water is essential for metabolic processes.
- Prioritize Sleep: Chronic sleep deprivation can disrupt metabolic hormones.
- Manage Stress: The stress hormone cortisol can negatively affect metabolic function.
Conclusion
Understanding what is the resting energy expenditure for a woman is fundamental for informed weight management. It's the baseline calorie requirement for survival, influenced by factors like body composition, age, and hormones. Using reliable estimation formulas and focusing on lifestyle factors such as strength training, adequate nutrition, and stress management allows women to better manage their metabolic health and achieve wellness goals sustainably. Accurate REE is more effective than guesswork or restrictive diets.
Key Takeaways
- Definition: Resting Energy Expenditure (REE) is the number of calories burned at rest for vital functions like breathing and circulation.
- Calculation: The Mifflin-St Jeor equation is the most accurate formula for estimating REE in women, using weight, height, and age.
- Influencing Factors: Key variables include lean body mass, age, hormonal status (including the menstrual cycle), and diet.
- Lifestyle Impact: Factors like strength training, adequate nutrition, sleep, and stress levels can all impact and improve REE.
- Avoid Crash Diets: Severely restricting calories can lower your metabolic rate, making sustainable weight loss more difficult.
- Foundational Knowledge: An accurate REE estimate is the basis for creating an effective and sustainable weight management plan.
